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Stone sheep and their habitat in the northern Rocky Mountain foothills of British Columbia Luckhurst, Alan John 1973

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STONE SHEEP AND THEIR HABITAT IN THE NORTHERN ROCKY MOUNTAIN FOOTHILLS OF BRITISH COLUMBIA by  ALAN JOHN LUCKHURST, B.Se.(Brit Col.)  A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REOUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN THE DEPARTMENT OF PLANT SCIENCE THE UNIVERSITY OF BRITISH COLUMBIA 1973  We accept t h i s t h e s i s as conforming t o the required standard  THE UNIVERSITY OF BRITISH COLUMBIA FEBRUARY 1 9 7 3  In presenting this thesis i n p a r t i a l fulfilment of the requirements f o r an advanced degree at the University of B r i t i s h Columbia, I agree that the Library s h a l l make i t freely available for reference and study.  I further agree that permission f o r  extensive copying of this thesis f o r scholarly purposes may be granted by the head of my department or h i s representative.  It is  understood that copying or publication of this thesis f o r f i n a n c i a l gain s h a l l not be allowed without my written permission.  Department of Plant Science The University of B r i t i s h Columbia Vancouver 8, B.C. Date  i  Abstract Stone sheep (Oyis d a l l i stonei) and a representative, undisturbed habitat f o r this species were studied i n the northern Rocky Mountain Foothills from May 1969 through May 1971.  A highly descriptive and  h o l i s t i c approach was taken i n this introductory study, with physiography, s o i l s , climate, and vegetation and the native sheep a l l being assessed. The study was concerned primarily with the alpine sheep habitat with emphasis on the c r i t i c a l winter range. Vegetation i n this northern environment, r e f l e c t i n g  physiographic,  climatic and edaphic d i v e r s i t y , presents a.complex, heterogeneous pattern l o c a l l y to a degree seldom observed i n more southern latitudes. Local variations i n climate, on different slopes and aspects, have produced s t r i k i n g f l o r i s t i c differences within short distances.  Moreover, s o i l s  developed over different bedrock formations and distrubed l i t t l e by glaciation contributed considerably to diversity i n the alpine habitat. Extremely acid s o i l s characterized by impeded drainage and low temperatures limited forage production over much of the habitat. However, s o i l s developed over calcareous parent materials on southern exposures had the favourable characteristics of moderately coarse texture, good drainage and an adequate nutrient status. These s o i l s supported r e l a t i v e l y productive plant communities and high quality forage for the sheep. The vegetation was also characterized by s t a b i l i t y especially i n the alpine zone; this zone i s largely free of a f i r e history and i s characterized by climax or long-term disclimax communities. Apparent deteriorating climate over long periods may be very s i g n i f i c a n t , however, because i n a l l likelihood they reduce favourable sheep habitat.  ii Stone sheep were almost entirely dependent on the herbaceous alpine vegetation for t h e i r n u t r i t i o n a l requirements.  Even though plant  succession proceeds slowly at these latitudes, serai grasslands tended to be invaded quite rapidly by shrubs which reduced the herbaceous cover and caused drifting snow to accumulate i n winter.  Grasses and sedges made up  95.6 percent of the winter diet and 78.5 percent of the f a l l diet of sheep collected i n the Nevis Creek study area. Vegetative d i v e r s i t y contributed largely to a balanced habitat f o r the sheep and the fortuitous combinations of factors of climate, s o i l s and vegetation provided c r i t i c a l winter range on largely snow-free slopes with southern exposures.  Three plant communities provided winter forage  but one, the Elymus - Agropyron community, provided almost 60 percent of the forage u t i l i z e d by wintering sheep. About 80 percent of the standing crop i n this community, which made up only about 20 percent of the winter range and four percent of the t o t a l productive habitat by area, was u t i l i z e d by the sheep. Although productivity was t y p i c a l l y low i n t h i s alpine ecosystem, forage quality was r e l a t i v e l y high and was maintained i n the cured  stage by hard f a l l frosts and the persistent winter cold.  Counts conducted i n summer and winter over an extensive portion of the northern f o o t h i l l s and Rocky Mountains showed stone sheep populations averaged 35 percent mature ewes, 28 percent mature rams, 15 percent yearlings and 22 percent lambs (n = 981).  Early summer counts f o r two seasons i n the  study area shewed an average r a t i o of 74 lambs per 100 ewes two years of age or older indicating a high b i r t h rate and low mortality i n the f i r s t few weeks of l i f e .  The lambs experienced almost 50 percent mortality by the  end of t h e i r f i r s t year; however, most of i t occurred early i n the f i r s t winter.  C l a s s i f i e d counts of the ram segment of the population indicate a  iii period of low mortality during adult l i f e to age 8 or 10 years.  Of course,  i n t r a s p e c i f i c competition and malnutrition during severe winter conditions, disease and parasites, injury, predation and hunting a l l contributed to mortality to some degree. Stone sheep populations r e f l e c t the s t a b i l i t y of t h e i r r e l a t i v e l y undisturbed alpine habitat. Actinomycosis and lungworm were common i n sheep at Nevis Creek but there i s no record of large-scale enzootic dieoffs i n this or other stone sheep populations such as occur i n bighorn populations due to lungworm-pneumonia disease. Stone sheep habitat, once remote, i s rapidly becoming more accessible and subject to man's influence with development of the north. Interference i n this northern environment by man must consider i t s s e n s i t i v i t y to abuse and i t s slew recovery.  Any change or destruction of this northern sheep  habitat, p a r t i c u l a r l y the important and r e s t r i c t e d elements such as the Elymus - Agropyron plant community on the Nevis Creek winter range, would unquestionably seriously reduce the sheep populations dependent upon i t .  iv  TABLE OF CONTENTS Page 1. INTRODUCTION 1.1 Background 1.2 The Study  1 1 2  2. AREA 2.1 2.2 2.3 2.4 2.5 2.6  3 3 4 4 4 5 6  3.  DESCRIPTION AND DISCUSSION Physiography and s o i l s Climate Economy and land use Flora Fauna The study area  PHYSIOGRAPHY, GEOLOGY AND SOILS 3.1 Background 3.2 Physiography 3.3 Geology 3.4 Soils 3.4.1. Soils below treeline .3.4.2. Alpine s o i l s 3.5. Discussion  9 9 9 9 12 12 18 23  4.  CLIMATE 4.1 Methods 4.2 Observations and results 4.2.1. A i r and s o i l temperatures 4.2.2. Precipitation and snow cover 4.2.3. Wind 4.3 Discussion  25 25 27 27 31 33 34  5.  VEGETATION 5.1 Methods 5.1.1. Plant communities below treeline 5.1.2. Alpine plant communities 5.1.3. Importance of plant communities to sheep 5.1.4. Forage production and quality on the winter range 5.1.5. Forage u t i l i z a t i o n and wastage on the winter range 5.2 Observations and results " 5.2.1. Plant communities below treeline (a) the Picea-Abies and north slope Picea-Abies communities (b) the Populus community (c) the Pinus-Salix community (d) the Betula^Pinus and Betula-Abies communities (e) the Betula-Salix community (f) the Salix-Betula and Salix-Epilobium communities (g) Valley meadow plant community  39 39 39 39 40 40 40 41 41 41 45 46 46 47 47 48  V  5.2.2. Alpine plant communities (a) the Betula-Vaccinium uliginosum and Betula-Vaccinium y i t i s - i d a i a communities (b) The Elymus-Agropyron community (c) the Elymus-Festuca community (d) the Dryas-Festuca community (e) the Calamagrostis-Hierochloe community (f) the Festuca-Dryas community (g) the Silene-Calamagrostis community (h) the Cryptogam-Salix community 5.2.3. Importance of plant communities to sheep 5.2.4. Forage production and quality on the winter range (a) Productivity (b) Forage quality 5.2.5. Forage u t i l i z a t i o n and wastage on the winter range 5.2.6. Discussion  48 48 50 57 59 59 74 75 75 76 77 77 78 78 80  6.  STONE SHEEP 6.1 Methods 6.2 Results 6.2.1. Seasonal movements and distribution 6.2.2. Foods and minerals 6.2.3. Population structure 6.2.4. Productivity 6.2.5. Juvenile and adult mortality 6.2.6. Mortality factors (a) competition f o r forage (b) disease and parasites (c) injury (d) predation (e) hunting 6.3. Discussion  7.  GENERAL DISCUSSION AND CONCLUSIONS  113  8.  LITERATURE CITED  118  9.  APPENDICES'  123  Klan in  pockef"  85 85 85 86 87 .92 96 99 101 101 102 104 104 106 106  LIST OF TABLES Table No.  page  1  Some chemical and physical properties of forest and valley s o i l s at Nevis Creek 19  2  Some chemical and physical properties of alpine s o i l s at Nevis Creek  21  3  Mean and extreme monthly temperatures (°F) at the Nevis Creek valley station, 1970  28  4  Mean and extreme temperatures ( F) a t Nevis Creek f o r the summer and winter of 1970/71  30  5  Precipitation totals at Nevis Creek and selected D.O.T. stations f o r the summer and winter of 1970/71  32  6  Mean wind v e l o c i t i e s (miles per hour) during the winter of 1969/70 and the summer of 1970 at bothe Nevis Creek climatic stations and a t two lowland stations  39  7  Padiation heat balance of selected surfaces at Nevis Creek on June 21, 1970  37  8  Plant communities studied below treeline at Nevis Creek  42  9  Relative abundance of major plants i n classes 1-5 f o r  10  four forest communities at Nevis Creek  43  Alpine plant communities a t Nevis Creek  51  11a  Major plant species coverage and frequency (C/F) f o r two sites i n the Betula-Vaccinium uliginosium l i b Shrub measurements and ground surface components f o r two sites i n the Betula-Vaccinium uliginosum community 12a Major plant species C/F f o r three sites i n the BetulaVaccinium v i t i s - i d a e a community 12b  54 55  Shrub measurements and ground surface components f o r three sites i n the Betula-Vaccinium v i t i s - i d a e a community 56  13a Major plant species C/F f o r three sites i n the ElymusAgropyron community 13b  53  60  Shrub measurements and ground surface components f o r three sites i n the Elymus-Agropyron community 61  14a Major plant species C/F f o r three sites i n the ElymusFestuca community  vii  LIST OF FIGURES Figure No. 1  page  Outline map of B r i t i s h Columbia shewing the location of the Nevis Creek study area  7  2  View of Nevis Mountain and alpine sheep ranges  8  3  Diagrammatic cross-section of the f o o t h i l l s ridge tentatively designated Nevis Mountain  9  4.  A Gleyed Cumulic Regosol p r o f i l e on an a l l u v i a l terrace  14  5  A Podsol p r o f i l e under the Picea community  14  6  A Degraded Dystric Brunisol p r o f i l e under open Pinus-Salix  15  7  A Chernozem-like p r o f i l e developed i n calcareous colluvium  16  8  A Degraded Eutric Brunisol p r o f i l e developed i n noncalcareous sandstone  16  9  A L i t h i c Degraded Dystric Brunisol p r o f i l e on the windswept summit  17  10  Climatic station at 5500 feet (1675 m) elevation on the sheep winter range, Nevis Mountain  26  11  The north slope Picea community  49  12  The Betula-Vaccinium v i t i s - i d a e a community  49  13  The Elymus-Agropyron community  58  14  The Elymus-Festuca community  58  15  The Dryas-Festuca community on exposed ridge  66  16  The Calamagrostis-Hierochloe community  66  17  The cryptogam-Salix community  18  Clipping grazed forage plots at s i t e 10A i n the ElymusAgropyron community  83  19  A temporary exclosure at s i t e 10A  83  20  Survivorship curve f o r stone rams i n the northern Rocky Mountains  .  71  100  viii  APPENDICES No.  page  1  S c i e n t i f i c and common names and authorities f o r plant species i d e n t i f i e d i n the Nevis Creek area  2  S c i e n t i f i c and common names and authorities for mammals  123  and birds mentioned i n text  132  3  Some t y p i c a l s o i l p r o f i l e s and additional s o i l s data  134  4  Miscellaneous climatic data and a l i s t of instruments used  141  ACKNOWLEDGEMENTS  The f i e l d work of t h i s project was financed by the B.C. Fish and W i l d l i f e Branch and the Canada Land Inventory (B.C.).  Office space,  laboratory f a c i l i t i e s and some technical services were provided by the Research D i v i s i o n , B.C. Fish and W i l d l i f e Branch and the Department of Plant Science, University of B r i t i s h Columbia. I am indebted t o Dr. V.C. Brink, Department of Plant Science and t o Dr. P.J. Bandy, B.C. Fish and W i l d l i f e Branch, for directing t h i s study. Dr. Ian McTaggart Cowan, Professor of Zoology and Dean of Graduate Studies, Dr. M. T a i t , Assistant Professor, Department of Animal Science, Dr. A.J. Renney, Professor, Department of Plant Science and Dr. M. Taylor, Professor, Department of Zoology, gave invaluable assistance and advice, p a r t i c u l a r l y during the preparation of the manuscript. I am grateful f o r the cooperation and assistance of many members of . the Canada Land Inventory (B.C.) team: t o Mr. D. Blower, project leader of the ungulate sector f o r permitting me to coordinate the f i e l d work of this study with my regular duties i n northeastern B.C.; to Mr. J.R. Marshall, project leader, agroclimatology sector, f o r assistance i n instrumentation and maintenance of climatic stations and the compilation of climatic data; also, t o Mr. R. Muir, Mr. C.W. Tremblay and Mr. R. Reid f o r technical advice and services. Mr. T.M. Lord, Pedologist, Canada Department of Agriculture, assisted i n the f i e l d and made valuable contributions to the section on soils.  To many members of the B.C. Fish and W i l d l i f e Branch including  Messrs. D.J. Robinson, Assistant Director, K. Sumamk, R.A. Demarchi,  X  F.E. Harper and D.A. Demarchi, a l l ' w i l d l i f e b i o l o g i s t s , I am grateful f o r t h e i r encouragement and valuable advice. Messrs. John Todd and Bob Marsh assisted greatly with the f i e l d work. For t h e i r cheerful acceptance of an often lonely task and a minimum of physical comforts, I owe them much. The f i e l d work was largely made possible and much more pleasant by the cooperation of Mr. Garry Vince and a l l members of the Wes Brown family of Fort St. John.  Their services and h o s p i t a l i t y throughout the study are  gratefully acknowledged. To these people and many others who contributed i n one way or another to t h i s study, I am deeply indebted.  1 1. INTRODUCTION  1.1 Background The native sheep of North America can be broadly divided into two groups, the bighorn (Ovis canadensis) i n the south and the thinhorn (Oyis d a l l i ) i n the north.  The stone or Stone's sheep (Ovis d a l l i stonei) i s one  of three races within the thinhorn group which inhabit an extensive area north of approximately latitude 56°N (Cowan, 1940). The stone sheep i s the most abundant native sheep i n B r i t i s h Columbia, and i s second i n abundance only t o i t s subspecific cousin the white d a l l sheep (Ovis d a l l i d a l l i ) i n North America.  Separated by less than a hundred miles from the northernmost  bighorn group, stone sheep range extends northward into the Yukon Territory, but l i e s mostly i n northern B r i t i s h Columbia, including much of the mountainous and high elevation plateau lands from the summit of the coast mountains to the eastern l i m i t s of the Rocky Mountain f o o t h i l l s . The vast area inhabited by t h i s native sheep i s s t i l l largely remote and uninfluenced by man and there i s l i t t l e ecological information f o r any part of i t .  The only previous detailed studies on stone sheep i n i t s  native habitat were carried out by Dr. Valerius Geist i n the Cassiar D i s t r i c t of B r i t i s h Columbia and were concerned mainly with the social behaviour of this sheep. In contrast to the northern regions inhabited by stone sheep, more southern latitudes of North America have experienced extensive ecological disturbance by man. As a result of man's influence, and particuarly his disturbance of t h e i r  habitat, bighorn sheep have suffered serious population  declines i n recent years (Buechner, 1960 and Stelfox, 1971). There i s much concern now at the pace with which man i s influencing his environment. The concern i s heightened because i t i s now d i f f i c u l t or  2 impossible to reconstruct o r i g i n a l conditions or to assess the ramifications of this disturbance.  Moreover, there i s l i t t l e or no documentation from  the past (Daubenmire, 1968). Stressing the imminent need for serious study of natural communities, Daubenmire (1968) points out that: "Soon the increasing demands of human populations w i l l have put a l l the land surface under management and destroyed p r a c t i c a l l y a l l natural ecosystems f o r eternity", and, ".. basic knowledge of the processes going on i n undisturbed communities has much t o offer i n helping t o manage the land for timber, game, forage, water and recreation". 1.2 The Study In keeping with these views and i n view of the rapid development of northern B r i t i s h Columbia, the objective of this study has been t o describe a more or less representative and pristine section of northern sheep habitat, before i t i s materially altered. A highly descriptive and h o l i s t i c approach was taken i n t h i s introductory study, with physiography, s o i l s , climate, vegetation and the native sheep a l l being assessed, i n some cases quite generally. In addition to providing new information on the habitat and population dynamics o f stone sheep i n the northern f o o t h i l l s , the study i s complementary to studies of bighorn and t h e i r habitat i n southern B r i t i s h Columbia and to studies of d a l l sheep and t h e i r habitat  presently underway i n the Yukon  and Northwest T e r r i t o r i e s . Through my work with the Canada Land Inventory (B.C.), I was able to make observations over much of the northern Rocky Mountain f o o t h i l l s , which contain a major portion of the better stone sheep habitat, and to select a r e l a t i v e l y accessible part of the area f o r t h i s study.  3  2. AREA DESCRIPTION AND DISCUSSION  2.1 Physiography and Soils The northern f o o t h i l l s p a r a l l e l the Rocky Mountains i n a belt f i f t e e n to forty miles wide and more than 350 miles long from south of the Peace River to the Liard River i n northeastern B r i t i s h Columbia (Holland, 1964). The underlying rocks, mainly of Mesozoic age, are greatly folded and faulted to produce a subdued mountainous topography characterized by a series of p a r a l l e l mountain ridges.  Relief and ruggedness vary, being  generally greatest i n the western h a l f ;  i n the main, the  summits are. about 2,500 feet (762 m) above the valley bottoms to reach elevations of about 6,500 feet (1,981 m). The longitudinal ridges are dissected by east-west through valleys which are generally wide and f l a r i n g as a result of glaciation. Glaciation has been comparatively l i g h t as indicated by the t h i n mantle of g l a c i a l d r i f t on valley floors, the absence of many g l a c i a l features and the close relationship of s o i l parent materials to underlying bedrock on mountain slopes. Precise s o i l data are lacking for the f o o t h i l l s but Brunisols, Podsols, Regosols and Gleysols appear to dominate while Chernozem-like s o i l s have developed l o c a l l y where parent materials and other s i t e factors are favourable; organic s o i l s occur on some poorly drained sites (Lord, pers. comm. 1972). The dominant drainage i s eastward and the f o o t h i l l s are characterized by a t r e l l i s pattern of drainage as streams make frequent right-angle turns to follow the northwest trending bedrock pattern (Holland, 1964).  4  2.2  Climate That part of B r i t i s h Columbia which l i e s east of the Rocky Mountains  i s dominated by Polar Continental and Polar P a c i f i c a i r and experiences long, cold winters and short, warm summers (Chapman, 1952), I t has the most continental climate of any part of the province with annual summer temperatures occasionally i n excess of 80°F (26.7°C) and temperatures below -50°F (-45.6°C) for short periods during most winters. Long term climatic data are lacking for the f o o t h i l l s .  Here the  climate i s modified somewhat from the prevailing climate of northeastern B.C. as i s i l l u s t r a t e d i n Section 4. 2.3 Economy and Land Use With an economy based on agriculture, o i l and natural gas, forestry and tourism, settlement and development i n northeastern B r i t i s h Columbia has proceeded at a rate w e l l above the provincial average i n recent years (Department of Lands, Forests and Water Resources,' (B.C.) 1968).  So f a r ,  t h i s a c t i v i t y has been limited mainly to the lowlands and, with the exception of the Alaska Highway which crosses them west of Fort Nelson, no all-weather roads occur i n the f o o t h i l l s north of the Graham River. Guided hunting parties have penetrated the f o o t h i l l s since the late 1920's and big game guiding i s s t i l l the main land use and economic a c t i v i t y . With the.abundance of game and limited access, the f o o t h i l l s area presently supports some of the most successful big game guiding operations i n the province (Bowden and Pearse, 1968). 2.4 Flora Two broad vegetation zones are recognized i n the f o o t h i l l s , (a) the Northern Foothills Section of the Boreal Forest Region, and, (b) Alpine tundra (Rowe, 1959).  5  White spruce (Picea glauca) and alpine f i r (Abies lasiocarpa) are the characteristic trees of the mature forest which has been largely replaced by serai lodgepole pine (Pinus contorta subsp. l a t i f o l i a ) , willows (Salix, spp.) and glandular birch (Betula glandulosa).  Poplar (Populus  balsamifera and P. tremuloides) dominate south facing slopes while grass sedge meadows with associated shrubs (Salix spp. and Betula glandulosa) occupy fine-textured a l l u v i a l s o i l s i n the valley bottoms. Widespread f i r e s have resulted i n the replacement of much of the spruce-fir forest i n the f o o t h i l l s by serai vegetation i n recent times. Both man-set and natural f i r e s have been a factor here but i t i s d i f f i c u l t to assess t h e i r r e l a t i v e importance.  In some parts of the f o o t h i l l s , man  has maintained,by repeated burning, open plant associations favoured by wild ungulates and horses.  Alpine vegetation i s extensive above treeline  which occurs at about 5,000 feet (1,524 m) altitude but extends to almost 6,000 feet (1,829 m) on protected slopes. Treeline i s often poorly defined where serai shrub meets the alpine zone. Alpine meadows of grasses and sedges occupy higher elevations and exposed locations where climatic and s o i l factors are favourable while mosses and lichens prevail on cold northern exposures and stable rock surfaces. 2.5 Fauna The prevalence of open plant associations and reduced snow cover i n the northern f o o t h i l l s favours an abundant and varied vertebrate fauna. In addition to stone sheep, moose (Alces alces) and caribou (Rangifer tarandus) are widespread and abundant while elk (Cervus canadensis), mule deer (Odocoileus hemionus) and mountain goat (Oreamnos americanus) are l o c a l l y abundant.  Large predators inhabiting the f o o t h i l l s include the  black bear (Ursus americanus), wolf (Canis lupus), g r i z z l y bear (Ursus  6  arctos), wolverine (Gulp luscus) and coyote (Canis latrans). 2.6 The Study Area During the study, observations were made throughout most of the f o o t h i l l s north of the Halfway River, but the main study area included approximately 6,500 acres (2,630 ha) i n the Nevis Creek area (see foldout map).  Within t h i s , main interest focused on 1,300 acres (526 ha) of alpine  habitat, on a t y p i c a l f o o t h i l l s ridge tentatively designated Nevis Mountain (Fig. 1). Located i n the outer f o o t h i l l s , 30 miles (48 km) on the leeward side of the Rocky Mountain c r e s t l i n e , Nevis Mountain rises to 6,675 feet (2,034 m) from the valley bottom at about 4,000 feet (1,220 m) altitude (Fig. 2). The valley contains a hunting camp and i s traversed by a seismograph road on which travel i s limited mainly to the winter months.  Except  f o r occasional t r a v e l through the valley and guided hunting, there has been l i t t l e a c t i v i t y by man. Fire and the ranging of horses are the only significant means through which man has influenced the native vegetation. Although the vegetation below treeline has been materially altered by f i r e , the alpine vegetation, except i n the shrub zone immediately above t r e e l i n e , has been undisturbed by f i r e and has not been used by domestic livestock.  8  Figure 2. View of Nevis Mountain looking north. Alpine sheep winter range i n the background. The Fopulus and Pinus• Salix communities- on an old burn-are' seen' i n the foreground.--  9 3. PHYSIOGRAPHY, GEOLOGY AND SOILS 3.1 Background The physiography and geology of the study area are described from f i e l d observations, from the interpretation of a i r photos and from physiographic and geological reports (Lord and McLean, 1964, Holland, 1964, P e l l e t i e r , 1964, P e l l e t i e r and Stott, 1963, McLean and Kindle, 1951). Soils were investigated at p i t s dug at one or more sites i n each plant community. Soils were described and c l a s s i f i e d according to the guidelines of the Canada S o i l Survey Committee (1970) as related by T.M. Lord, pedologist, Research Station, Canada Agriculture, Vancouver, B.C.  S o i l features recorded  at each s i t e included: drainage and nature of the parent material as w e l l as horizon number, thickness, texture, structure and colour. S o i l samples were analyzed at the Canada Agriculture Research Station, Vancouver, B.C. 3.2 Physiography The study area i s physiographically varied, extending across a broad glaciated valley and including the southern two-thirds of 6,675 foot (2034m) Nevis Mountain.  Nevis Mountain, a t y p i c a l f o o t h i l l s mountain ridge, abuts  the north side of the east-west trending valley.  The upper portion of the  valley i s occupied by Nevis Creek which makes an abrupt turn northwards at the eastern end of the study area, to p a r a l l e l , and thus largely contain, Nevis Mountain.  Nevis Creek just north of the study area joins the Besa River.  The broad valley, occupied i n i t s upper reaches by Nevis Creek, continues eastward to completely penetrate the f o o t h i l l s , and meet the Alberta Plateau, some ten miles beyond Nevis Mountain.  I t i s occupied i n i t s outer reaches  by the Buckinghorse River which flows east, across the plateau surface. 3.3 Geology The f l o o r and lower slopes of the through valley occupied by Nevis  10 Creek and the upper Buckinghorse River are covered by a t h i n mantle of glacial drift.  The presence of granitic material from the Canadian Shield  at the eastern edge of the study area indicates that continental i c e sheets reached the area (W.H. Mathews, per. comm. (1971)). However, g l a c i a l erosion was mainly a result of i c e moving eastward through the valleys and the g l a c i a l d r i f t consists mostly of Palaeozoic limestone, chert and sandstone from the western mountains (Pelletier and Stott, 1963).  North-  westerly trending valleys such as the valley containing lower Nevis Creek were not eroded but did., receive a mantle of d r i f t when the i c e receded (Holland, 1964). Although valley bedrock i s largely covered by g l a c i a l d r i f t , rocks of the Buckinghorse Formation are exposed where Nevis Creek cuts deeply into them along the eastern edge of Nevis Mountain.  These rocks consist  mainly of acidic dark grey marine shales ( P e l l e t i e r , 1964). Glaciation has been l i g h t above t r e e l i n e although limestone e r r a t i c s , scattered sparsely to the summit of the mountain ridge, indicate complete ice cover from the west at some stage (W.H. Mathews, per. comm. (1971)). The sedimentary rocks of the northwesterly dipping a n t i c l i n a l ridge, designated as Nevis Mountain, can be described on the basis of groups and individual stratigraphic units ( P e l l e t i e r and Stott, 1963) (see Fig. 3). The Bullhead group of lower Cretaceous age and the Schooler Creek group of Triassic age dominate.  The younger Bullhead rocks  which p r e v a i l on eastern and northern slopes are mainly siliceous sandstones, siltstones and shale of an acidic nature. Rocks of the Bullhead group have been largely eroded from the southern and southwestern slopes and from the peaks of Nevis Mountain, exposing the older rocks of the Fernie Formation and Schooler Creek Group. The Fernie Formation i s r e l a t i v e l y t h i n ,  FIGURE 3 Diagrammatic cross-section of the Foothills ridge tentatively designated Nevis Mountain Capping of Schooler Creek limestones on peaks  Scree and erosionol debris from Schooler Creek Group and Bullhead Group Bullhead Group  Scree and erosionol debris from Schooler Creek Group and Bullhead Group  Bullhead Group-continuous on NW slope eroded from most of SW slope  Buckinghorse Formation eroded to expose rocks of the Bullhead Group  Quaternary drift and colluvium -Stream  Quaternary drift and colluvium  Alluvial terrace Nevis Creek Buckinghou. __ formation |  Buckinghorse Formation  Strotiographic Units and Undivided Groups f-'plj  Buckinghorse Formation - mainly dark gray marine shales (Lower Cretaceous age) Bullhead Group - mainly siliceous marine sandstones and siltstone (mainly Lower Cretaceous age) Fernie Formation - less than 100feet thick-mainly rapidly weathering dark calcareous siltstone and shale with phosphatic chert (Jurassic age) Schooler Creek Group - mainly limestones, calcareous siltstones,shales and sandstones (Triassic age)  12  and l i t t l e exposed here.  I t consists mainly of rapidly weathering dark  calcareous siltstones and shale with phosphatic chert.  The  Schooler  Creek group, several thousand feet i n thickness, consists mainly of limestones and calcareous siltstones and shales.  I t includes strata which  form massive limestone c l i f f s and ledges on the western slope and strata which contain numerous marine f o s s i l s including brachiopods (Halobia sp. and Monotis sp.), pelecypods (Gryphaea sp.), cephalopods (Ammonoidea sp.) and large marine vertebrates. 3.4 Soils 3.4.1. Soils below treeline Soils below treeline have developed on a l l u v i a l , c o l l u v i a l and g l a c i a l t i l l deposits (Fig. 1).  Selected chemical analysis of a Gleyed Cumulic  Regosol occuring on recent alluvium are presented i n Table 1 ( s i t e #16). This s o i l had 4 cm of Ah horizon over 11 cm of AGg horizon.  These upper  horizons overlie several s t r a t i f i e d layers, including a buried Ah, which have a wide range i n texture (Fig. 4). The pH values obtained show the s o i l i s strongly acid i n the surface horizons and pH increases to neutral with depth. The organic matter, t o t a l C and the C:H r a t i o are very high i n the Ah horizon, and the organic matter content remains high i n the subsoil horizons.  Although the s o i l i s imperfectly and poorly drained and occurs  i n a cold environment, i t has a cation exchange capacity that i s favourable for plant growth. Podsols, Brunisols and Gleysols have developed on g l a c i a l t i l l and c o l l u v i a l deposits that cover most of the forested lower mountain slope. A mini-Humo-Ferric Podsol developed on g l a c i a l t i l l ( s i t e #15) i s characterized by a Bf horizon 10 cm thick which i s overlain by a l i g h t coloured Ae 5 cm thick and an equal thickness of forest l i t t e r (Fig. 5).  13 The pH values shew that although the Ae and Bf horizons are extremely acid, a horizon i n which the reaction i s mildly alkaline occurs at HO cm. The high l e v e l of available phosphorus i s related to the high t o t a l phosphorus and i s probably a mineral source at this lew pH (4.1).  Organic  matter i s r e l a t i v e l y low and the C.E.C. i s only s l i g h t l y lower than that of the Cumulic Regosol.  I t i s a moderately well-drained s o i l under a  closed forest canopy. Frost persisted i n the subsoil u n t i l mid-summer. For a more complete description of this and other characteristic s o i l s i n the study area see Appendix 3. A Degraded Dystric Brunisol has developed on well-drained slopes with a serai Pinus-Salix cover.- A t y p i c a l example of this s o i l i s described at s i t e #12 (Table 1).  I t i s characterized by a Bin horizon 30 cm thick  overlain by 20 cm of light-coloured Ae and a t h i n cover of forest l i t t e r . The Bm horizon i s low i n organic matter (0.55%) and nitrogen (0.053%) and the Ae horizon, which has only s l i g h t l y higher values, has a high C:N r a t i o (14.4).  On d r i e r sites with a more open canopy the Bm horizon i s less  pronounced and the Ae horizon more weakly eluviated (Fig. 6). Humic Gleysols have'developed on cold, northern exposures and are presently underlying thick moss-lichen layers and support an open canopied Picea-Abies forest.  A Humic Gleysol a t s i t e #17 had a f i h r i c organic H  horizon 10 cm thick with no noticeable e l u v i a l or i l l u v i a l horizons (Table 1).  Percent organic matter (45.72) and nitrogen (1.1319) are high, but  i t i s poorly drained with frozen subsoils and has an unfavourably high C:N r a t i o (20.2). Chernozem-like s o i l s (see section 3.4), i n contrast to Humic Gleysols on cold northern exposures, have developed on steep southern exposures under moderately dense stands of small poplar (Populus tremuloides and P. balsamifera),  Figure 4. A Gleyed Cumulic Regosol p r o f i l e on an a l l u v i a l terrace. Note the predominantly fine-textured layers.  Figure 6. A Degraded Dystric Brunisol p r o f i l e under open Pinus-salix. Note the bunchgrass (Festuca scabrella) on this open canopied s i t e .  Figure 7. A Chernozem-like p r o f i l e developed i n calcareous colluvium. Note the depth of the Ah, the lower boundary of which i s narked by the knife Iso the productive ground cover i n which grasses predominate  Figure 8. A Degraded Eutric Brunisol p r o f i l e developed i n non-calcareous sandstone  Figure 9. A L i t h i c Degraded Dystric Brunisol p r o f i l e on the windswept summit. Note the shallowness of the p r o f i l e and the sparse vegetative cover.  18 and dense lyme grass (Elymus innovatus). A black Chernozem-like s o i l a t s i t e A l i s characterized by an Ah horizon 20 cm thick over a dark brown Bm horizon 5 cm thick (Table 1). This s o i l , developed on calcareous marine sandstone, to a depth of 70 cm has physical and chemical properties favourable for plant growth. Results of the analysis show the Ah horizon to be high i n organic matter (25.08%) and available nitrogen (1.134%) with a favourable cation exchange capacity (55.63 me/10Og). The C:N r a t i o of this well-drained sandy loam s o i l was found to be moderately high (12.8) and the reaction was s l i g h t l y a c i d i c .  The high reading f o r available  phosphorus i n the BC horizon may be related to the favourable pH of 6.8. The s o i l described at s i t e A2 has similar characteristics (Table 1). 3.4.2. Alpine Soils Because there i s very l i t t l e g l a c i a l debris a t higher a l t i t u d e s , there i s a close relationship: between alpine s o i l s and the underlying sedimentary rocks from which they have developed. Eutric Brunisols and Black s o i l s are closely associated on the south . and west-facing slopes of Nevis Mountain. These s o i l s have developed on neutral to s l i g h t l y calcareous parent materials derived from rocks of the Schooler Creek group. Black Chernozem-like s o i l s were found on steep (59 to 70%) southern exposures of the lower alpine slopes (Sites 10A, 10B and 10C).  They were characterized by Ah horizons 10 to 20 cm thick.  A brown (7.5 YR 3/2m)* Bm horizon was present i n a l l these s o i l s and free lime was present i n the lower B.C. of C l horizons of the s o i l s at sites 10A and 10C. (Fig. 7). These are well-drained loam s o i l s that have developed to a depth of 70 cm or more. As the analysis results f o r s i t e 10A indicate, these s o i l s are high i n organic matter and nitrogen and have a high cation  Table 1., Some chemical properties of forest and valley soils at Nevis Creek  Site . Soil elev. Parent aspect . Material slope(%)  Soil ' Order and • Classif.  Organic Matter(%)  Horizon,  Organic '." N(%) = C:N • ratio Carbon(%) :  CEC me/100g  . Exchange Cations (me /lOOg)". " " (pp~ Ca K  •  16 Alluvium'' Regosolic Gleyed Comulic 4050(1234) Regosol Flat  Ah . ACg . Cl C2  4.7 24.98 . 4.4 6.19 5.8. -if. 34 7.2' 2.14  20.31  1.32 0.32 0.20 0.10  15.  15 Glacial 4200(1280) t i l l E 17  Podzolic Mini-HomoFerric Podzol  Ae Bf BCk  3.1 4.1 7.5  1.06 1.79 1.27  0.63 1.03  0.05 100.08 - l l * 0.06 I •  12 Colluvium 5150(1559) S 15  Br^tnisolic Degraded Dystric Brunisol  Ae . Bm BC  3.4 3.8 4.4  1.76 0.55 0.17  1.02 0.32  0.07 i l H . ' 6. 0.05 0.03 !  17 Colluvium 4525(1378) NE 28  Gleysolic Humic Gleysol  H  6.6  45.72  26.58  1.32  55.63 19.68 16.66 9.58  29.29 8.57 14.88 26.36  0.64 0.09 0.05 0.05  6.98 12.74 5.51.  0.37 3.17 20.49  0.06 10.6 0.09 164.3 0.04 1.5  31.2 31.5. 20.8 7.4 20.6 427.2 8.2  20. i I-  Al Calcareous Black . 4925(1494) Marine Chernozem-like S Sandstone 61  Ah Bm BC  6.2 6.3 6.8  25.08 9.03 5.30  A2 Calcareous Black 49 0 0(149 3) Marine Chernozem-like 5 Sandstone 70  Ahe  5.5  22.11  " Available P. as determned by the Bray #2 method  14.55  12.13  i n appendix  1.13 0.42 0.30  12. , 12. 10.  55.63 31.73 23.90  51.29 30.08 24.99  0.37 0.07 0.08  30.3 8.2 10.2  1.05  11.  47.58  36.73  0.76  25.8  120.6 102.4 487.5  20 exchange capacity and a favourable C:N r a t i o (Table 2). A L i t h i c Humisol occurred at higher elevations on a steep southwestfacing slope at s i t e 3A. developed  At t h i s s i t e , an H horizon 18 cm thick has  d i r e c t l y on a calcareous C horizon and was overlain by an L-H  horizon 2 to 3 cm thick.  This s o i l , infused by basic seepage waters, i s  high i n organic matter ( 39.83 percent),'has a high cation exchange capacity (88.15 me/100 g.) and a moderately high C:N r a t i o (13.7).(Table 2). In several respects this s o i l  i s similar to the Chernozem-like  s o i l s with  which i t i s grouped here for descriptive purposes. Eutric Brunisols were found on s l i g h t l y acid to neutral parent materials derived from weathered rocks of the Schooler Creek group. These s o i l s , as shown for s i t e ID, 2C and 2B i n Table 2, have t h i n (5 to 12 cm), grayish brown Ahe horizons and dark brown Bm horizons 15 to 21 cm thick that overlie BC or C horizons i n which free lime i s generally absent (Fig.8). They are s l i g h t l y acidic with favourable texture and only moderately high C:N r a t i o s (Table 2). Regosols and Degraded Dystric Brunisols occur on the east slope of Nevis Mountain. These predominantly shallow, loam and sandy loam s o i l s have developed on parent materials derived from acidic rocks of the Bullhead group. They are very strongly to extremely acid (pH 4.8 to 3.5 i n the upper horizon) and w e l l to imperfectly drained. A t y p i c a l L i t h i c Dystric Brunisol i s characterized by a t h i n (5 cm), very dark grayish brown (10 YR 3/2 d) Ahe over a brown (10 YR 3/3-3/2 d) sandy loam Bm horizon (Fig. 9). As indicated by the analysis results for sites 4B and IC respectively, the Ah horizon i s high i n percent organic matter (20.65 and 12.14), low i n percent nitrogen (0.831 and 0.633) and has moderately high C:N ratios (14.3 and 11.0) (Table 2).  Table 2. Seme chemical properties of alpine s o i l s at Nevis Creek Site elev. Aspect Slope  Soil Parent Material  Soil Order & Classif.  Organic Horizon Texture PH Matter(%)  Exchange Cations Organic C:N C.E.C. (meg/ l00g) Carbon(%) N(%) r a t i o meg/1 OOg Ca ' K P  (ppm)  Ah BC  L L  6.0 6.4  17.86 4.78  10.36 2.7  0.96 0.26  11. 10.  10A Calcareous Black 5075(1546)Colluvium Chernozemlike S  Ah BC  L L  6.4 7.5  27.11 1.65  15.72  1.38 0.09  11.  61.75 8.90  55.99 .0.-44 20.86 0.05  9.5 0.0  101.7 55.6  3A Calcareous L i t h i c 6100(1859)Colluvium Humisol SW 65  H  SiL  6.8  39.83  22.55  1.65  14.  88.15  83.59  7.3  48.3  Brunisolic Bm ID Neutral 5500(1676)Weathered Orthic Degraded C l S Sandstone Eutric Brunisol 40  L L  5.7 6.6  2C Neutral Brunisolic Ahe 56 00 (17 07 leathered L i t h i c Degraded SW Sandstone Eutric Brunisol 26  LS  6.0  27.97  16.41  1.17  14.  2B Neutral 5775(1759) Weathered SW Sandstone 26 1C Acidic 5450(1650)Sandstone SE  Brunisolic Ahe L i t h i c Degraded Bm Eutric Brunisol BC  LS FSL FSL  6.0 6.1 7.1  9.57 3.88 3.48  5.55 2.25  0.38 0.18 0.17  15, 12.  Brunisolic Ae L i t h i c Degraded Bm Dystric Brunisol BC  FSL L L  4.8 4.4 4.0  12.14 4.48 3.44  7.0 2.61  0.63 0.22 0.14  11. 11. 12.  10B Calcareous L i t h i c Black 4990(1521)Sandstone ChernozemS like 63  0.61  32.50 18.93 0.38 20.46 9.06 0.13 11.64 3.95 0.10  10.3 7.1 6.8  ,. .  M  Table 2. (continued)  5A Acidic 6000(1829Marine E Siltstone 16.,  Brunisolic Ahe Gleyed Dystric Em  SL SL  3.5 3.6  4B Acidic 6420(19 57)Quartzite undulating 6 Sandstone  Brunisolic Lithic Dystric Brunisol  L SL SL  3.5 3.6 3.7  Ahe Bm BC  20.65 2.74 2.79  11.96 1.60  0.8314. 0.1 '/ 11. 0.12 11.  33.35 13.64 13.50  4.87 0.61 0.51  0.16 0.04 0.04 .  33.5 41.1 24.4 34.9 49.8 104.0  * Available P by the Bray 2 method  ro ro  23  Humic Gleysols occurred both above and below t r e e l i n e on slopes w i t h a c o l d northern exposure., A L i t h i c Humic G l e y s o l described a t s i t e #17 below t r e e l i n e i s c h a r a c t e r i z e d by an H h o r i z o n , h i g h i n organic matter (45.72 %) and n i t r o g e n (1.319%) (Table 1).  The C:N r a t i o was h i g h i n t h i s  c o l d , p o o r l y drained s o i l which had permafrost pockets i n seepage s i t e s . The s o i l found above t r e e l i n e on t h i s c o l d exposure had s i m i l a r characteristics . 3.4 D i s c u s s i o n The study a r e a i s p h y s i o g r a p h i c a l l y and g e o l o g i c a l l y d i v e r s e .  The  s o i l s r e f l e c t t h i s d i v e r s i t y , s t r i k i n g l y so i n the case o f a l p i n e s o i l s which were developed on parent m a t e r i a l s d e r i v e d d i r e c t l y from c o n t r a s t i n g underlying bedrock formations. Although l i t h i c p r o f i l e s a r e common, the a l p i n e s o i l s g e n e r a l l y a r e c h a r a c t e r i z e d by loam o r sandy loam t e x t u r e s , high carbon and n i t r o g e n values and adequate l e v e l s o f those p l a n t n u t r i e n t s t e s t e d f o r .  Potassium  l e v e l s tended t o be low b u t phosphorus l e v e l s are v e r y h i g h , due, i n p a r t , to t h e supply o f inorganic phosphorus from sedimentary parent m a t e r i a l s . E u t r i c B r u n i s o l s and Black s o i l s which p r e v a i l on southern and western exposures have t h e favourable c h a r a c t e r i s t i c s o f moderately coarse t e x t u r e , good drainage and an adequate n u t r i e n t s t a t u s , p a r t i c u l a r l y the Black s o i l s which have developed under a very favourable m i c r o c l i m a t e . The Black s o i l s a r e c l a s s i f i e d as Chernozem-like s o i l s because o f p o s s i b l e temperature r e s t r i c t i o n s which, i f a p p l i c a b l e , would r e q u i r e t h a t they be c a l l e d A l p i n e E u t r i c B r u n i s o l s according t o the Canadian system o f s o i l c l a s s i f i c a t i o n (Lord, per. comm. (1972)).  Terminology i s based on a  c r i t i c a l temperature o f 0°C (32°F) and although a mean temperature o f -2.5°C (27.5°F) was recorded a t the v a l l e y s t a t i o n i n 1970, i t i s thought t h a t  24  the s o i l s  i n q u e s t i o n d e v e l o p e d i n a m i c r o c l i m a t i c environment w i t h a  mean a n n u a l temperature i n e x c e s s o f 0°C (J.R. M a r s h a l l , p e r . comm.(1972)). I n c o n t r a s t t o the B l a c k s o i l s and  E u t r i c B r u n i s o l s on  e x p o s u r e s , Humic G l e y s o l s c o n t a i n i n g f r o z e n l a y e r s o c c u r r e d exposures and D y s t r i c B r u n i s o l s and R e g o s o l s o c c u r r e d s l o p e and windswept r i d g e s n e a r the mountain t o p . on c o o l e x p o s u r e s , f e r t i l i t y i s l i m i t e d by c o n d i t i o n s and  extreme a c i d i t y .  r a t i o s a r e u n f a v o u r a b l y h i g h due under lew  M o t t l i n g and  on  northern  on t h e h i g h  In these l a t t e r  eastern soils  temperatures, saturated g l e y i n g a r e common, and  t o the slow breakdown o f o r g a n i c  s o i l t e m p e r a t u r e s , i n t h e s e , and  s o i l s i n the v a l l e y b o t t o m .  low  southern  i n fine textured  C:N  matter  alluvial  25 4. CLIMATE Methods Two climatic stations were located i n the study area i n 1969,  one  i n September at 4,050 feet (1234 M) altitude i n the valley bottom and  one  i n July at 5,500 feet (1675 M) a l t i t u d e i n the centre of the alpine winter range for sheep (Fig. 10).  The location of these stations, which i n future  are referred to as the "valley" and "mountain" stations respectively, i s shown on the fold-out  map.  Since no long-term climatic records are available for the northern f o o t h i l l s , the stations were designed to measure general climatic parameters. Instrumentation  at each of the climatic stations included a hygrothermograph  and minimum thermometer housed i n a Stevenson screen, two simple open r a i n gauges and an anemometer. In addition, a maximum thermometer and a s i x month continuous recorder (which measured a i r temperature and precipitation) were located at the mountain station. Snow depth recording stakes, readable from the valley f l o o r with binoculars, or from a low-flying a i r c r a f t , were located on the south-facing slopes of Nevis Mountain i n two a l t i t u d i n a l transects from 5,100  t o 5,250 feet (1555 to 1600 M) and from 5,450 to  5,500 feet (1661 to 1675 M).  S o i l thermistors which could be read with a  telethermometer were located 10 and 20 inches (25 and 50 cm) below the s o i l surface at both stations i n May,  1970.  The mountain station was serviced once a week during the summer i n 1969 and 1970  and the valley station was serviced once a month as f a r as was  possible up to and including June, 1971.  Snow cover was measured period-  i c a l l y by reading levels on snow stakes located on the alpine winter range and by actual measure at ten random locations at the valley station. In addition to providing the instrumentation f o r the stations, the  26  Figure 10. Climatic station at 5,500 feet (1675 M) elevation on the sheep winter range, Nevis Mountain  27 climatology sector of the Canada Land Inventory compiled and assisted i n summarizing and interpreting climatic data.  Where necessary, missing  climatic data f o r Nevis Creek were interpolated using data from Canada Department of Environment (formerly Department of Transport) meteorological stations at Fort St. John a i r p o r t , Fort Nelson airport and Fort Nelson Churchill mines (J.R. Marshall, 1970). Fort St. John airport at 2,775 feet (844 M) altitude i s located near Fort St. John on the Peace River lowlands 125 miles (201 km) southeast of Nevis Creek.  Fort Nelson a i r p o r t , at 1,230 foot  (375 M) altitude i s located on the Fort Nelson lowland, 105 miles (168 km) northeast of Nevis Creek and Fort Nelson Churchill Mines at an altitude of 5,015 feet (1527 M) i s located i n the Rocky Mountains 105 miles (168  km)  northwest of Nevis Creek. 4.2 Observations and Results Considerable climatic data were l o s t due to malfunctioning or damaged instruments and servicing d i f f i c u l t i e s at Nevis Creek. However, a complete monthly record of a i r temperature was obtained f o r the valley station during the 1970 calendar year; the record permits direct comparison with standard data from other stations.  Otherwise, the data presented are f o r the year,  a r b i t r a r i l y divided into a f i v e month summer (May 1 to September 30) and seven month winter (October 1 to A p r i l 30) f o r which the most complete seasonal records were obtained. Additional climatic data and a complete l i s t and description of climatic equipment used are included i n Appendix 4. 4.2.1. A i r and s o i l tanperatures In 1970, the valley station had an annual mean d a i l y temperature of 27.5°F (-2.5°C), a mean maximum of 39°F (3.9°C) and a mean minimum of 14.4°F (-9.8°C). An extreme maximum of 81.0°F (27.2°C) was recorded i n August and a minimum of -49.9°F (-45.5°C) i n January (Table 3). The mean d a i l y temperature exceeded 32°F (0°C) f o r f i v e months from May to September, but  28  Table 3. Mean and extreme monthly temperatures (°F) at the Nevis Valley Station, 1970 Month  Mean Maximum  January  *(8.9)  (35.1)  February  29.9  41.1  March  30.8  April May June  Period Maximum  Period Mean Minimum Minimum (-14.1)  Mean Daily  6.6  -49.9 -21.0  ((-2.6) 18.4  40.4  6.9  -10.4  18.9  41.2  50.1  16.4  -5.0  28.8  (55.0) 62.5  69.6 79.6  (32.0) 35.8  (21.8) 26.5  (43.0) 49.2  62.3 63.3  74.8 81.0  35.4 35.5  25.0 24.5  48.9 49.4  September October  52.4 (42.2)  66.0 59.9  29.4 (21.4)  9.0 2.0  40.9 31.7  November December  (11.8) (7.3)  43.3 39.1  (-2.5)  -30.6 -32.0  4.6 -0.9  July August  Mean Annual 39.0  (-9.0) 14.4  27.5  " Brackets indicate values which have been determined, at least i n part, by interpolation  29 several degrees of f r o s t were recorded during every month of the year i n 1970. The mean and extreme temperatures f o r the summer and winter periods of 1970/71 are shown f o r both stations a t Nevis Creek i n Table 4. Daily mean temperatures were comparable f o r the two stations during the summer months. However, the mountain station had a smaller mean diurnal range of temperatures with a mean maximum averaging 6.0°F lower and a mean minimum 4.7°F higher than the valley station.  Higher minimum temperatures resulted  i n a mean minimum above 32°F (0°C) f o r a l l f i v e summer months a t the mountain station as opposed to only 3 months a t the valley station.  While seven or  eight degrees of frost were recorded a t the valley station i n July and August, only one degree of f r o s t was recorded during these months a t the mountain station.  Department of Transport records (1970) show that mean  d a i l y temperatures exceeded 32°F f o r seven months from A p r i l to October and that the months of June, July and August were frost-free at the lowland stations of Fort Nelson and Fort St. John airports. During the winter months, a mean d a i l y temperature of 12°F was recorded at the valley station.  Records were obtained f o r only three winter months  at the mountain station when mean maximum temperatures averaged s l i g h t l y higher and mean minimum temperature several degrees lower than at the valley station.  Rapid and substantial temperature changes occurred i n winter and  temperature inversions resulted i n differences of 40°F or more between the valley bottoms and mountain slopes on occasion. The limited record obtained during 1970 indicates that well-drained s o i l s a t the valley station had thawed t o a depth of 20 inches by the end of the f i r s t week i n May.  Moderately well-drained s o i l s at the mountain  station remained frozen at t h i s depth f o r another month. However, a temperature of 35. 5°F (1.9°C) was recorded i n well-drained s o i l s adjacent  TABLE 4. Mean and extreme temperatures ( F) at Nevis Creek f o r the summer and winter of 1970/71 Valley Station Mean Extreme max. max.  Mean min.  Extreme min.  Mean daily  Mean max.  Mountain Station Extreme Mean max. min.  Extreme min.  Mean daily  May  ^ (55.0)  69.6  32.0  (21.8)  43.0  47.4  56.9  34.1  22.5  40.9  June  62.5  79.6  35.8  26.5  49.2  56.7  74.1  41.0  28.5  48.9  July  62.3  74.8  35.4  25.0  48.9  56.8  71.8  42.0  31.0  49.4  August  63.3  81.0  35.5  24.5  49.4  55.7  76.9  40.1  31.0  47.9  September 52.4  66.0  29.4  9.0  40.9  49.2  61.8  34.2  18.3  41.7  46.3  53.1  Av. Mean Summer  59.1  October  (42.4)  59.9  (21.4)  November  (11.8)  (43.3)  (-2.5)  December  (7.3)  (39.1)  (-9.0)  January  5.4  38.2  February  25.7  March April  33.6  38.3  45.8  (31,7)  missing  missing missing  missing  missing  (-30.6)  (4.6)  missing  missing missing  missing  missing  (-32.0)  (-0.9)  missing  missing missing  missing  missing  -19.5  -48.0  -6.6  -49.0  -10.4  43.9  0.6  -25.9  13.2  missing  missing missing  missing  missing  24.4  39.6  -0.9  -26.0  11.7  17.4  30.0  2.5  -15.3  10.0  41.2  60.3  19.6  -11.0  30.4  (33.0)  (51.7)  (19.2)  (-2.8)  (26.1)  Av. Mean Winter 22.6 ' 1.2 1 Brackets indicate interpolated values  2.0  ' 12.0  -1.1  missing  35.0  -19.7  missing  missing 00  °  31 to the mountain station on June 2nd and alpine s o i l s on a 60 percent slope with a southern exposure had thawed to a depth of at least 20 inches by May 14.  Soils on steep southern exposures probably thawed much sooner than  s o i l s i n the valley bottom.  In contrast, alpine and forest s o i l s on a  northern exposure s t i l l had frozen layers within twenty inches of the surface two months after the summer s o l t i c e . I t should be pointed out that s o i l thermistors a t the valley station were located i n coarse gravels as opposed to those a t the mountain station which were located i n fine t o medium textured loams.  Unfortunately  no temperatures were recorded i n fine-textured a l l u v i a l s o i l s which prevailed i n the valley bottom.  Much lower s o i l temperatures would be  expected i n the fine textured a l l u v i a l than i n the gravelly s o i l s i n which the thermistors were located a t the valley station.  S o i l temperatures at  the 2o inch depth averaged 49.2°F (9.4°C) a t the valley station and 38.0°F (3.3°C).at the mountain station during June, July and August. S o i l temperatures had dropped t o 40°F (4.y4°C) from a high of 44°F (6.6°C) by August 29 at the mountain station and had dropped to the same l e v e l from a high of 56°F (13.3°C) by September 13 at the valley station. Ambient a i r temperatures indicate that they would have been frozen by September 15 a t the valley station and by September 20 or possibly as early as September 11, at the mountain station. 4.2.2. Precipitation and snow cover Precipitation t o t a l s f o r the summer and winter seasons of 1970/1 a t Nevis Creek and other selected stations are shown i n Table 5. Summer precipitation t o t a l s a t the valley and mountain stations were similar.  Most of t h i s precipitation f e l l as r a i n , but snow occurred i n  May, August and September.  32 During the winter of 1970/71, the mountain station received approximately 5.70 inches (12.7 cm) of precipitation f o r a t o t a l of 18.10 inches (46 cm) during the year beginning May 1, 1970. In winter, precipitation f a l l s as snow which covers the ground unevenly because of different exposure to sun and wind.  To i l l u s t r a t e :  During the l a s t two weeks of January, 1969, the northern f o o t h i l l s experienced clear, cold weather with l i t t l e wind and the valleys and mountain slopes had a continuous snow cover of about 10 t o 18 inches (25.4 to 45.7 cm). Three weeks l a t e r , after a period of milder weather, with many windy days, almost two feet (30.5 cm) of snow lay i n the valley bottoms while many exposed slopes and ridges were completely snow-free. A transect from valley bottom, at 4,350 feet (1,326 M) a l t i t u d e , to the lower alpine slopes of a f o o t h i l l s ridge i n late February, 1969, showed the snow cover averaged 21.8 inches (55.4 cm) and varied from 20 t o 22 inches (51 t o 56 cm) i n the v a l l e y bottom which supported a scattered cover of low-growing Salix spp. On slopes of 38 to 66 percent with a southern aspect, snow depths averaged 14.7 inches (37.3 cm) and varied from 13.5 to 16.0 (34.3 to 40.6cm) inches under a moderate cover of Populus spp. Above 5,000 feet (1524 M) a l t i t u d e on alpine slopes of 50 to 80 percent with a southern exposure, snow depths ranged from 0 to 22 inches (0 t o 56 cm) depending on exposure to wind. In the valley bottoms at Nevis Creek, a more or less continuous snow cover persists from early November u n t i l late A p r i l (Garry Vince, per. comm. 1970). Winter snow depths averaged 8 inches (20.3 cm),at the valley station i n 1969/70 and 9.1 inches i n 1970/71. The maximum recorded snow depth was three feet ( .91 m ) and included some snow which had accumulated through d r i f t i n g .  During the winter of 1970/71, snow depths averaged only  32(b)  Table 5. Precipitation totals at Nevis Creek and selected D.O.T.* stations f o r the summer and winter of 1970/71 Station  Summer (inches)  Winter (inches)  Annual (inches)  Nevis Valley  11.98  missing  missing  Nevis Mountain  12.40  5.70**  18.10**  Fort St. John A  8.46  7.81  16.27  Fort Nelson A  11.65  5.36  17.01  Fort Nelson Churchill Mines  22.48  11.00  33.48  * Department of Transport (now Department of Environment) ** Approximate  33 3 or 4 inches (8 or 10 cm) on the exposed south-facing slopes of Nevis Mountain. D r i f t s i n excess of three feet occurred but snow-free areas were common on exposed s i t e s .  By the end of the f i r s t week i n  May, only occasional patches of d r i f t e d snow remained on southern and western exposed alpine slopes while northern and eastern exposures had a continuous cover u n t i l late May or early June. Alpine slopes with a southern or western exposure had less than a month of continuous snow cover during the entire winter of 1970/71 (Garry Vince, per. comm. 1970). 4.2.3. Wind Mean wind v e l o c i t i e s at the mountain station were more than double those at the valley station i n 1969/70. Mean wind v e l o c i t i e s recorded at Nevis Creek and at two lowland stations (D.O.T. 1970) during the winter of 1968/70 and the summer of 1970 are shown i n Table 6. Table 6. Mean wind v e l o c i t i e s (miles per hour) recorded the winter of 1969/70 and the summer of 1970 a t both Nevis Creek climatic stations and two lowland stations Station  Winter  Summer  Mean Annual  4.5  3.8  4.2  Nevis Mountain  10.2  8.6  9.5  Fort Nelson A  4.0  4.8  4.4  Fort St. John A  8.5  8.6  8.6  Nevis Valley  During the summer, periods with no measurable wind were few and b r i e f at the mountain station.  The highest mean v e l o c i t i e s were  recorded during the f i r s t week i n July (19 m.p.h.) (30.6 km.p.h.) and during the two weeks i n mid-August (16.5 m.p.h. (26 km.p.h.), but  34 moderately high v e l o c i t i e s were also recorded i n early summer from May 11 to June 26 (12.2 m.p.h.) (19.6 km.p.h.). Higher wind v e l o c i t i e s were recorded at both stations f o r the winter than f o r the summer period, even though the winter i s characterized by periods of calm or r e l a t i v e l y l i g h t winds. 4.3 Discussion A description of the climate and i t s role i n the ecology of the study area i s limited by the short, two-year period f o r which climatic data were gathered and by a lack of microclimatic data. In general, the climate f i t s the description of Chapman (1952) f o r northeastern B r i t i s h Columbia with variations due to l o c a l r e l i e f and the proximity of the mountains.  The influence of l o c a l r e l i e f was  reflected i n cooler mean ambient a i r temperatures (see Table 4 and Appendix 2), and s l i g h t l y higher precipitation totals (see Table 5), especially at the mountain station, than at lowland stations east of the foothills. Long term records (Department of Transport, 1967 and 1968) indicate that mean temperatures and frost-free periods a t Fort Nelson and Fort St. John differed l i t t l e i n 1970 from the long-term climatic normals. The degree of continental!ty, as measured by the mean diurnal temperature range, was greater a t the valley station and smaller at the mountain station i n 1970 than a t the lowland stations east of the foothills.  During the summer, skies over the f o o t h i l l s were often  overcast during at least part of the day due to moist P a c i f i c a i r invading from the west.  A variety of orographic clouds formed on the  crest, while lanes of clear sky marked the troughs of airflow waves i n  35  the lee of the Rocky Mountains. Sudden and often violent l o c a l storms were a common feature during the summer. Winds of medium velocity were broken only b r i e f l y by periods of calm or by sudden gusts during l o c a l storms. In winter, more stable polar continental a i r dominates northeastern B r i t i s h Columbia and the cold northern skies are more frequently clear (Chapman, 1952).  In the f o o t h i l l s area, periods of cold with  r e l a t i v e l y calm winds were broken by periodic invasions of warmer P a c i f i c a i r which brought strong winds. The winds descending i n the lee of the Rocky Mountains were probably further warmed adiabatically contributing to rapid and substantial temperature changes observed during such times.  The winds funnelled down the broad valleys which  penetrate the f o o t h i l l s and caused a rapid reduction i n snow cover on exposed slopes. Maximum wind v e l o c i t i e s were not measured during the study but high winds were experienced on several occasions.  In December, 1969,  :  both climatic stations were damaged by winds, with an estimated average speed i n excess of 70 miles per hour (112.7 km.p.h.) and gusts that approached or exceeded 100 miles per hour (170 km.p.h.) (Garry Vince, pers. comm.). This contrasts with maximum observed hourly speeds of 40 and 55 miles per hour (64.4 and 88.5 km. p.h.) and probable maximum gust speeds of 57 and 72 miles per hour (92 and 116 km.p.h.) recorded at Fort Nelson and Fort St. John stations respectively during the twelveyear period from 1955 to 1966 (Canada Department of Transport, 1968). Although no attempt was made to measure microclimatic parameters during t h i s general study,- the climate near the ground varied greatly within the study area.  The important influence of slope and aspect was  36 indicated by the presence of frozen layers within twenty inches (50 cm) of the s o i l surface of a northern exposure while s o i l s of a steep southern exposure were thawed t o that depth by early spring. To demonstrate the influence of insolation, the t o t a l heat balance received due to solar energy by surfaces of different slopes and aspects at Nevis Mountain on June 21, 1970, are shown i n Table 7. The calculations are based on the following equation: (I + i ) (1.' - °0 -R^  =  R where I represents direct short wave  radiation, i represents diffuse short wave radiation, <* represents the albedo,  represents incoming long wave radiation and R represents  the net radiation heat balance (Wang, 1963).  The equation was  calculated using the mean ambient a i r temperature recorded at the valley station during the 18 hour period between sunrise and sunset and assuming completely clear skies and a herbaceous ground cover with an albedo of .82 calories per square centimeter per day. Table 7. Radiation heat balance of selected surfaces a t Nevis Creek on June 21, 1970 Surface Exposure  Slope  Calories per square centimeter per day Radiation heat balance  South  Horizontal  458  South  45 percent  467  West  45 percent  385  East  45 percent  383  North  45 percent  200  North  110 percent  40  As shown i n Table 7 the net energy received by a slope of 45 percent with a southern aspect i s almost 2 1/2 times that received by  37 a surface with the same slope and a northern aspect and almost twelve times that received by a 110 percent slope with a northern aspect.  Over the growing season the radiation heat balance received  by steep south-facing slopes would be s i g n i f i c a n t l y greater than that received by f l a t surfaces or north and east-facing slopes. The influence of microclimate was also shown by s t r i k i n g differences i n the f l o r i s t i c s and net productivity of plant communities i n the study area as discussed i n Section 5. Although specific climatic requirements and limitations of range plants are unknown f o r the study area, they have been investigated elsewhere. Conrad (1950) has suggested that a mean d a i l y temperature of ^2°F (5.5°C) i s satisfactory f o r the growth of many perennial plants and Harper (1961) found that continuous spring growth of range plants i n the Ashnola area of B r i t i s h Columbia commenced when the mean temperature rose to this l e v e l .  Harper '(1961) found that growth was  terminated by a moisture deficiency i n mid-summer and that the short growing season was a main factor l i m i t i n g net productivity on the Ashnola ranges. The ^2°Y threshhold i s very near the peak of the mean monthly temperature curve at Nevis Creek during the growing season.  Also,  mean d a i l y temperatures generally fluctuated quite widely about the monthly mean with minimum temperatures frequently dropping below freezing l e v e l .  In f a c t , the frost free period was only nine days i n  duration at the valley station and sixteen days i n duration at the mountain station i n 1970.  In view of the mean d a i l y temperature range  and the high incidence of f r o s t , during the growing season at Nevis Creek, i t does not appear meaningful t o apply the usual standards f o r  38 measuring growing season to the growth of native plants i n this area. Soils on most sites were s t i l l frozen some time after the date at which mean d a i l y temperatures reached the 42°? threshold.  In addition  to being able to withstand several degrees of f r o s t , seme species are capable of growth when s o i l temperatures are at or near freezing l e v e l and early emergence may occur due to s o i l surface wanning while subsoils are s t i l l frozen.  For most herbaceous plants, however, the surface  onset of continuous spring growth probably depends on/soil temperatures reaching a threshold value somewhat above 32°F (0°C). The growing season i s short and while growth may be terminated by a moisture deficiency on some dry s i t e s , on most sites i t appears to be terminated by severe frost i n late summer or early f a l l .  39  5. VEGETATION 5.1 Methods Plant communities were delineated and sites selected f o r study following the interpretation of 20 chain (1:15,840) a i r photos and ground reconnaissance (Lord, T.M.  and A. McLean, 1969). A cover type map  was compiled on a 40 chain (1:31,680) topographic base with correction for slope and photo d i s t o r t i o n (see foldout map).  Plant communities  which were too small, or too poorly defined to map individually,were symbolized on the cover map i n complex with the symbol f o r the major community with which they were associated.  The area occupied by plant  communities was determined with a compensating polar planimeter. 5.1.1. Plant Communities Below Treeline Plant Communities below treeline were broadly defined and were studied only b r i e f l y using general  transects and a simple system of rating species  by abundance ocularly because sheep do not use them to  any extent.  Trees  were aged by counting the annual rings at a 2 foot (61 cm) stump height except i n the Populus community where they were aged at a 4 inch (10 stump height. meter transects  The Populus community was studied  cm)  using four f i f t e e n  i n a straight l i n e sequence equidistantly  spaced. Tree ages, number per unit area, height and diameter at 4.5 feet (1.14 m) were determined by measuring a l l trees i n three randomly selected 1. by 3 meter belt plots along each vegetation transect. 5.1.2. Alpine Plant Communities Alpine plant communities on which the sheep depended almost exclusively were studied and described i n greater d e t a i l than communities below treeline. A quantitative macroplot method for the description and c l a s s i f i c a t i o n of range vegetation (Poulton and Tisdale, 1961) was used with some modifications  40 i n the study of alpine vegetation.  Modifications included the use of a  one meter, rather than a four foot belt along the 15 meter transect l i n e . Also, average shrub heights and crown diameters were determined by measuring a l l shrubs i n one by three meter belts along each transect l i n e .  The  foliage intercept of shrubs was measured along each transect l i n e i n those communities where shrubs were a major species.  The canopy coverage method  of vegetational analysis (Daubenmire, 1959) was used to determine species percent cover and frequency and to measure ground surface components within each macroplot. Ten locations were studied at 1.5 meter intervals along each 15 meter transect l i n e using the one tenth square meter observation frame described by Daubenrnire. On areas too small f o r more detailed study, paired 15 meter transects were used instead of a macroplot.  One to four sites were studied i n each  community, depending on i t s size and v a r i a b i l i t y . 5.1.3. Importance of Plant Communities to Sheep The importance of plant communities to sheep was determined from a e r i a l and ground observations, discussions with guides and prospectors familiar with the area and by counting a l l p e l l e t groups within the 1 by 15 meter vegetation transects. P e l l e t groups were counted i f at least h a l f the group lay within the transects. 5.1.4. Forage Production and Quality on the Sheep Winter Range A measure of primary productivity and forage available f o r wintering sheep was determined by clipping and weighing the herbaceous cover on 127 replicated y i e l d plots from 10 study sites i n the three major plant communities on the winter range. The pre-clipped y i e l d p l o t s , protected from grazing animals by fencing, were clipped to one h a l f inch above ground l e v e l and the vegetation removed was oven dried to constant weight at 105°  C.  A measure of forage quality was obtained by determining t o t a l nitrogen  41 from milled samples of pooled forage from the 1970 f a l l y i e l d and spring u t i l i z a t i o n plots (see Section 5.1.5) using the macro Kjeldahl method (Association of Agricultural Chemists, 1960). Percent riitrogen was multiplied by 6.25 to obtain crude protein estimates. The overwinter decline i n crude protein was represented by the difference i n crude protein content of forage from the f a l l y i e l d plots and weathered forage from the spring u t i l i z a t i o n plots. 5.1.5. Forage u t i l i z a t i o n and Wastage on the Winter Range Forage removed by overwinter grazing and wastage from the three p r i n c i p a l plant communities on the winter range was represented by the difference i n oven-dried forage weights from fenced y i e l d plots and 108 replicated u t i l i z a t i o n plots established adjacent to the fenced enclosures.  The  u t i l i z a t i o n plots were clipped to one half inch above ground l e v e l before new growth began i n the spring.  Overwinter loss, due to weathering, was  represented by the differences i n forage weights from ungrazed plots clipped i n the spring and replicated plots clipped the previous f a l l . 5.2 Observations and Results 5.2.1. Plant coninunities below treeline Plant communities defined and described below treeline occupied about 5,200 acres (2,104 ha) including s i x communities i n which forest trees were major species, three i n which shrubs were major species and one i n which grasses, sedges and forbs were predominant. They are l i s t e d , with descriptive features, i n Table 8.  A l i s t of major plant species occurred i n four of the  forest communities i s shown i n Table 9. (a) The Picea-Abies and north slope Picea-Abies communities The Picea-Abies plant community represents the mature boreal forest vegetation which would occupy most of the area below t r e e l i n e , or about  42 Table 8. Plant communities studied below treeline i n the Nevis Creek area Plant Cammunity  Site No.  Elevation feet(metres)  Slope Aspect S o i l (%) Order  Area acres (hectares)  A. Forest: 15  4200(1280)  28  E  18  4525(1378)  28  NE Gleysolic  14  4450(1355)  30  W  Brunisolic 2704(1904)  Betula-Pinus ( F ) 13  5150(1559)  15  E  Brunisolic  Betula-Abies (F^) *  4800-5500 (1462-1675)  25-70  Picea-Abies P^r-  Podsolic  (  North slope Picea-Abies  cry"  Pinus-Saliix(F ) 2  ?  Populus (A)  (NW-E) Brunisolic  1400(567)  168(68) 40 (16)  A.^ and 4925(1494)  60  S  Brunisolic  4900(1493)  70  S  Brunisolic  *  3950-4250 (1203-1294)  0  -  Regosolic  222(90)  Salix-Betula (T) *  3950-4250 (1203-1294)  0  Regosolic  220 (89)  Betula-Salix (S ) *  variable  variable  variable Regosolic -  0  Regosolic  A  2  220(89)  B. Shrub: Salix-Epilobium TBT^—  2  C. Grassland: Valley meadow (G_) 16  4050(1234)  "Bracketed symbols correspond t o symbols used i n cover map Reconnaissance only.  A l t i t u d i n a l ranges and s o i l types are tentative  64 (26)  43  Table 9.  Relative abundance of major plants given i n f i v e classes (A -E ) for four forest communities i n the Nevis Creek area  Species  Picea  Pinus-Salix  TF^T  Betula-Pinus  TFJ5  Betula-Abies  CFJ5  CT 5 4  A. Trees: Picea glauca  4  Abies lasiocarpa  I  1  X  X  Pinus contorta  3  2  1  X  2  5  I 1  3  1 1  5 4 3 3  s u b s p .l a t i f o l i a Populus spp. B. Shrubs: Betula glandulosa Salix spp. Vaccinium uliginosum Vaccinium v i t i s - i d a e a 1  Arctostaphylos uva-ursi Empetrum nigrum Ledum groenlandicum Juniperus communis  1 1 X 1  3 I 3  2 1 X  X  2 1 X 1  I 1  Shepherdia canadensis Rosa a c i c u l a r i s  1 1 I 1  1 1  C. Forbs: Linnaea borealis P o t e n t i l l a spp. Epilobium angustifolium Saxifraga tricuspidata  X  Cornus canadensis  X  I X  X  1  X 1  I  Lupinus arcticus Artemisia norvegica D. Grasses: Festuca scabrella Other species^  X  I I X X  X  X  X 1  X 1  1 1 X X  2 I  "  44  Table 9. ( c o n t ' d ) .  Species  Picea  E . Mosses and l x c h e n s  3  5  Pinus-Salix (F2)  3  Betula-Pinus (F3)  2  Betula-Abies  <v 5  I n d i c a t e s t h e s p e c i e s o c c u r s commonly b u t has been a s s i g n e d an_. abundance r a t i n g l e s s t h a n o n e . S p e c i e s n o t h a v i n g an abundance r a t i n g o f one o r more f o r a t l e a s t one community a r e n o t l i s t e d h e r e . m a i n l y S a l i x g l a u c a b u t S . s c o u l e r i a n a , S. m y r t i l l i f o l i a , S_. s u b c o e r u l e a and S_. a l a x e n s i s a r e common a s s o c i a t e s and S_. l a n a t a o c c u r s i n F ^ . m a i n l y Poa s p p . , C a l a m a g r o s t i s l a p p o n i c a and Elymus  innovatus  I d e n t i f i e d by D r . W. S c h o l f i e l d ; specimens lodged i n t h e U n i v e r s i t y o f B.C. h e r b a r i u m  45 5,000 feet  altitude i n climax or near climax condition.  Only remnant stands  of t h i s forest community remained i n the study area because of widespread f i r e s i n the recent past. In remnant forest stands  150 to 200 years i n age,  white spruce (Picea glauca) was the dominant species and Abies lasiocarpa, a common associate which increased i n r e l a t i v e abundance with elevation. The forest understory was characterized by a moderate to sparse layer consisting mainly of Salix spp. and Betula glandulosa and a ground cover dominated by mosses and lichens (see Table 9). Mature forest vegetation was supported by Pcdsols except on cold, northern exposures where Gleysols occur. Cold northern exposures support a forest community (North slope PiceaAbies) i n which the same tree species are dominant but productivity i s lower and the canopy cover i s more open. The Salix-Betula shrub layer i s more dense, and a thick mat of hydrophilic mosses and lichens covers the forest f l o o r (Fig. 11). The Picea-Abies and north slope Picea-Abies communities were not always separated on the cover map. Together they occupied about 1,400 acres (567 ha). (b) The Populus Community This community i s a long-term sub-climax which occupied 220 acres (89 ha) on steep southern exposures.  Black and Dark Gray s o i l s t y p i c a l l y  supported a mixed woody and herbaceous plant cover. Two s i t e s , with slopes of 60 and 80 percent had an average density of 5,225 aspen (Populus tremuloides) and 4,887 balsam poplar (P. balsamifera) trees per acre. The trees, averaging 27.4 years old at a four inch stump height, averaged only 13.1 feet (4 m) i n height and 1.9 inches (4.8 cm) i n diameter at breast height. A productive ground cover of grasses and forbs was dominated by lyme grass (Elymus  46 irmovatus).  Cryptogams were a minor component and the ground surface cover  averaged thirty-two percent l i v i n g vascular plants and sixty-three percent litter. (c) The Pinus-Salix community This i s a sere developing a f t e r f i r e s which occurred extensively within the Picea-Abies forest about f i f t y years ago.  There i s considerable  v a r i a b i l i t y depending mainly on slope, aspect and canopy. The cover tends to be open and, except under a dense tree canopy .consisting mainly of lodgepole pine (Pinus contorta subsp. l a t i f o l i a ) , the understory i s w e l l represented, with the shrubs Betula glandulosa, Salix spp. and lingonberry (Vaccinium vitis-idaea) occurring commonly (Table 9). This community, which occupied more than 2,700 acres (1093 ha), was supported by Brunisols with Podsols and Gleysols occurring on cool s i t e s . (d) The Betula-Pinus and Betula-Abies communities These conmunities are open forest associations near t r e e l i n e . Both have a well-developed shrub layer of Betula and Salix under an open or scattered tree cover. The Betula-Pinus community occurs on the steep south-facing slopes of draws and represents a serai stage following the extensive f i r e s which occurred about f i f t y years ago.  I t occupies a t o t a l of 168 acres (68 ha)  and i s characterized by scattered or open stands of Pinus contorta which have replaced the Abies and Picea of the mature forest (Table 9). The Betula-Abies community occupies 40 acres (16 ha) on the northfacing slopes of draws and on protected benches. The vegetation on these cooler exposures i s rarely subject to f i r e and the cover consists mainly of mature Abies lasiocarpa (Table 9). A w e l l developed shrub layer consisting mainly of Betula glandulosa and Salix glauca i s characteristic and where burns  47  have occurred, these species form a dense cover which slows forest succession and persists unchanged f o r long periods.. (e) The Betula-Salix community This plant community i s widespread, but i t has a discontinuous distribution i n close association with other communities so that i n most cases i t was not delimited on the cover map and i t s extent was not determined. I t occurs on a variety of sites with abundant s o i l moisture and good drainage, mostly on seepage sites near treeline and i n protected places i n the alpine meadows. Betula glandulosa and Salix glauca  are the dominant species which  alone, or i n association, form a dense cover about a meter high.  Common  associates include Elymus innovatus, bluegrasses (Poa spp.), common fireweed (Epilobium angustifolium), t a l l mertensia (Mertensia paniculata), alpine and heart-leaf arnica (Arnica alpina and A. c o r d i f o l i a ) , groundsel (Senecio lugens) and Indian paintbrush ( C a s t i l l e j a niiniata). (f) The Salix-Betula and Salix-Epilobium communities These plant communities which occupy a t o t a l of 220 acres (89 ha) have developed on better-drained a l l u v i a l terraces and recent stream deposits respectively.  The Salix-Betula community i s characterized by a more dense  cover of shrubs and a reduced cover of grasses and forbs but otherwise the communities are f l o r i s t i c a l l y similar and they are described c o l l e c t i v e l y below. Both communities are dominated by shrubs including silvery-green willow (Salix subcoerula) (2)", glaucous willow (S. glauca) (2), Scoulers willow (S. scouleriana) (1) and Betula glandulosa (2). Common forbs include large flowered fireweed (Epilobium latifolium ) (3), common h o r s e t a i l (Equisitunr: arvense) (2), Mertensia paniculata (1), T i l e s i i sage (Artemesia T i l e s i i H l ) and numerous minor species. Grasses having a combined abundance rating of * Bracketed numbers indicate r e l a t i v e abundance rating i n classes 1 to 5  48 3, included rough fescue (Festuca scabrella), bluegrasses (Poa arctioa), P. nevadensis and P. fendleriana), tufted hairgrass (Deschampsia caespitosa), polar grass (Arctagrostis l a t i f o l i a ) , spike trisetum (Trisetum spicatum) and Elymus innovatus. (g) Valley meadow plant community Meadows have developed on oold, fine textured Regosols of poorly drained terraces i n the valley bottoms.  Small meadows, less than 25 acres  (10 ha) i n extent and t o t a l l i n g only 64 acres (24 ha) i n the study area are interspersed with the Salix-Betula community which appears to be gradually invading them. Grasses, forbs and sedges are the major plant species i n the meadows, including: Festuca scabrella (4), reed-bent grass (Calamagrostis lapponica) (2), sedges (Carex spp.) (2), meadow rue (Thalictrum occidentale) (2), monkshood (Aconitum delphinifolium (1), Poa spp. (1), northern bedstraw (Galium boreale) (1), Trisetum spicatum (1), Mertensia paniculata (1), Epilobium angustifolium (1) and many minor species. 5.2.2. Alpine Plant Communities Approximately 1300 acres (526 ha) of the study area occurred above t r e e l i n e , of which f i f t y percent was comprised of rock, scree or lichen communities.  Shrub and alpine meadows made up another 25 percent each of  the alpine area. Nine alpine communities; v i z . two shrub communities; s i x grass-forb communities and one cryptogam-forb community are l i s t e d i n Table 10 and described below. (a) The Betula-Vaccinium uliginosum and Betula-Vaccinium v i t r i s - i d a e a communities These are r e l a t i v e l y stable shrub associations which have a f i r e history.  They occupy a combined t o t a l of 232 acres (94 ha) on the lower  western and eastern alpine slopes respectively.  Each community was sampled  Figure 11. The north slope Picea community. Note the abundance of shrubs and the t h i c k mat of mosses and l i c h e n s on the f o r e s t f l o o r .  Figure. 12. The. Betula vaccinium v i t i s - i d a e a community on the e t slope of Nevis'Mountain. I n the background Nevis Creek cuts deeply i n t o the Buckinghorse shales a s  50  with three paired transects (Tables 11a and l i b ) .  Both communities  were characterized by an abundance of Betula glandulosa and a sparse cover of grasses and forbs (see F i g . 12), but had  significant f l o r i s t i c  difference i n other respects. Alpine blueberry (Vaccinium uliginosum) was next i n importance to Betula glandulosa i n the west slope community while this position was occupied by lingonberry (Vaccinium vitis-idaea) i n the east slope community. Rough fescue (Festuca scabrella) and sheep fescue (Festuca ovina) were the two major grass species i n the community on the west slope. Forbs were more abundant i n this community, including species such as spotted saxifrage (Saxifraga tricuspidata), bellflower (Campanula lasiocarpa), Epilobium angustifolium, alpine bistort (Polygonum viviparium) and lupine (Lupinus arcticus) which were not recorded i n the east slope community. S o i l moisture i s more abundant and grasses are more prevalent i n the community on the cooler east slope. The two major grasses were holy grass (Hierochloe alpina) and Calamagrostis lapponica, but Festuca scabrella was most abundant i n seepage s i t e s . Soils were shallow and stony and cryptogams averaged 57 percent of the ground surface components. Shrub densities and crown diameters were not measured i n either  of these communities because the shrubs tended to  reproduce vegetatively and form inseparable mats. (b) The Elymus-Agropyron community This plant community occurs i n small, discontinuous or fragmented units which were not delimited on the cover map, but are symbolized i n complex with the closely associated Elymus-Festuca community. I t i s confined to Chernozem-like s o i l s developed i n calcareous parent materials on steep south-facing slopes below 5,500 feet (1676 m) elevation. The s o i l s support a productive cover of grasses, predominantly Elymus innovatus and  Table 10. Alpine plant communities at Nevis Creek; t h e i r extent with topography and s o i l characteristics Plant ccmmunity  Site No.  Elevation Slope feet (meters) %  Aspect  Betula-Vaccinium uliginosum (S1W)  : 13A 13B  5350(1630) 5400(1645)  Betula-Vaccinium vitis-idaea (S1E)  6A 6B 6C  5680(1730) 34 5575(1698) 38 5700(17397) 32  NE  10A 10B 10C  5120(1561) 5000(1524) 5150(1559)  59 52 59  Elymus-Festuca (GI)  1A IB 1C ID  5450(1662) 5325(1622) 5500(1676) 5500(1676)  Dryas-Festuca (G2)  2A 2B 2C 5A 5B 5C 5D  Soil Great Group  Geologic Parent Material  Area acres (hectares'.  Shrub:  Alpine grass and herbs Elymus-Agropyron (GIB)  CalamagrostisHierochloe (G4)  46 50  W w  *(Eutric Brunisol)Acidic-neutral sandstone and shales  136.4(55.2)  (Dystric Brunisol Acidic sandstones and Regosol) and shales  142(57.5)  S S S  Eutric Brunisol  Calcareous colluvium Calcareous sandstone Calcareous colluvium  15 (6.1)  43 53 40 48  S SW SE SE  Eutric Brunisol Eutric Brunisol Dystric Brunisol Eutric Brunisol  Calcareous sedimentary rock Acidic sandstone Neutral sandstone and colluvium  60(24.3)  5700(1737) 5775(1759) 5650(1722)  26 26 26  SW SW SW  Eutric Brunisol Eutric Brunisol Eutric Brunisol  Neutral weathered sandstone  42 (17)  6000(1829) 6300(1919) 6200(1890) 6250(1905)  24 18 24 35  ESE E E E  Dystric Brunisol Acidic marine s i l t s t o n e Dystric Brunisol Acidic marine siltstone Dystric Brunisol Acidic marine s i l t s t o n e Regosol Acidic marine siltstone  E.NE  n  190(76.9) Cn H  Table 10. (Cont'd) Plant Community  Site No.  Elevation Slope feet(meters)" %  Aspect  56 68  Geologic Parent' Material  Humisol Regosol  Calcareous colluvium (Marine sandstone and siltstone)  Festuca-Dryas (G5)  3A 3B  6100(1859) 5810(1771)  Silene-Calamagrostis TG3l  4A 4B  6350(1935) undulating 6420(1957) undulating  -  Dystric Brunisol Acidic sandstone Dystric Brunisol Acidic sandstone  Cryptogam - Salix (N)  18  5300(1615)  N  Humisol  35  SW SW  Soil Great Group  Colluvium  Area acres(hectares) 19(7.7)  3(1.2) 20(8.1)  it  Bracketed figures are tentative  cn  53  Table 11a. Major plant species coverage and frequency (C/F) f o r two sites i n the Betula-Vaccinium uliginosum community Species  A.  B.  13B  Grasses:  C/F  C/F  Festuca scabrella Festuca ovina Poa a r c t i c a  tr/5 2/55 tr/10  8/35 2/55 2/55  2/40 tr/5  2/40 1/10  5/60 1/40 1/45 1/30 tr/5 tr/20 tr/25 0/5  5/75 3/55 1/35 1/45 2/15 1/35 tr/10 1/45  20/70 19/55 9/25 . 2/5 tr/5  39/70 10/40 10/25 tr/5 1/10  Sedges: Kobresia myosuroides Carex atrata  C  Forbs: Saxifraga tricuspidata Campanula lasiocarpa Epilobium angustifolium Polygonum viviparum Lupinus arcticus Luzula spicata Art ernesia norvegica S t e l l a r i a longipes  D.  Study Site 13A  Shrubs: Betula glandulosa Vaccinium uliginosum Vaccinium v i t i s - i d a e a Arctostaphylos uva-ursi Rhododendron lapponicum  Tr = Trace or less than 0.5%  54  Table l i b . Shrub measurements and ground surface components f o r two sites i n the Betula-Vaccinium uliginosum community Species and Components A.  B.  Shrubs  Study s i t e  13A I (%) x  Av.Ht.(ins)  I(%)  13B Av.Ht.(ins)  Betula glandulosa  28  7.4  2.3  6  Vaccinium uliginosum  14  2.5  6  2.1  Vaccinium v i t i s - i d a e a  4  0.5  4  0.5  Rhododendron lapponicum  0  2  2  Ground surface components (%) Living vascular plants Litter Rock Bare s o i l  20 20 38 0  Cryptogams  23  = Foliage intercept i n percent along 15 meter transect  20 15 25 0 40  55  Table 12a. Major plant species C/F, f o r three sites i n the Betula-Vaccinium v i t i s - i d a e a community Species  6A C/F  A.  Festuca ovina Festuca scabrella Pea leptoccma  C/F  C/F  10/80  8/60  14/90  11/70 1/45 5/40 3/60  6/30 0/0  11/80 2/75 3/30  1/15  tr/20  1/35 1/50 1/5  tr/5 tr/20 0/0  3/35  Forbs: Luzula spicata S t e l l a r i a longjpes Artemesia norvegica  C.  6C  Grasses: Hierochloe alpina Calamagrostis lapponica  B.  Study Site 6B  2/30 1/65 0/0p  Shrubs: Betula glandulosa 61/100 Vaccinium vitis-idaea 2/10 Vaccinium uliginosum 4/15 Ledum groenlandicum 0/0  Tr  = trace or less than 0.5%  59/95 12/35 4/10 5/35  68/100 16/50 5/15 0/0  56  Table 12b. Shrub measurements and ground surface components f o r three sites i n the Betula-Vaccinium v i t i s - i d a e a community  Species and Components A.  Shrubs: Betula glandulosa Vaccinium v i t i s - i d a e a  I(%)  Av.Ht.(Ins)  I(%)  6C  Av.Ht.(Ins) I(%)  Av.Ht. Ins  40  4.7  37  4.8  38  5.5  1  0.5  7  0.5  2  2.0  2  4  2  7  2.0  1  2  0  Vaccinium uliginosum Ledum groenlandicum  Study Site 6B  6A  0  B. Ground surface components (%) Living vascular plants Litter  22.5 22.5  21  29  16  31  Rock  10  18  9  5  1  0  40  44  24  Bare s o i l Cryptogams  57  bearded wheatgrass (Agropyron subsecundum) (Fig. 13). which was sampled at three sites  The community,  using paired 15 meter transects (Table  13 a 8 b) i s characterized by having the most favourable microclimate and s o i l s for forage growth and was the most productive and heavily grazed of the alpine communities studied. The annual growth i s almost completely removed by grazing sheep each winter, and the vegetation i n this community, both i n terms of f l o r i s t i c s and productivity, must be considered a product, i n part, of heavy grazing, trampling and f e r t i l i z a t i o n with f e c a l matter, (c) The Elymus-Festuca community This community, supported by Eutric Brunisols, dominates alpine slopes with a southern exposure (Fig. 14). Broken by unvegetated scree and rock, and by components of the Betula-Salix and Elymus-Agropyron communities, i t occupies a l i t t l e more than half of the south-facing slopes of Nevis Mountain or about 60 acres (24 ha). slopes ranging  I t i s described at four sites with  from forty to f i f t y - t h r e e percent and aspects from southwest  to southeast (Table 14). The vegetation, which i s dominated by Elymus innovatus and Festuca scabrella, r e f l e c t s the v a r i a b i l i t y of slope, aspect and s o i l s .  Festuca scabrella has a wide tolerance range and i s one of the  most widespread and abundant grass species i n the study area as a whole. I t favours areas where snow covers the slopes i n winter and where there i s an abundant supply of s o i l moisture, and, i n the Elymus-Festuca community, Festuca scabrella i s r e l a t i v e l y more abundant than sedges (Kobresia myosuroides) on cool, wet sites and more acidic s o i l s .  Elymus innovatus favours warmer  slopes and less acidic s o i l s while wheatgrass (Agropyron subsecundum and A. violaceum) are restricted to warm slopes with neutral to alkaline s o i l s . There i s an abundance and variety of forbs, but white dryas (Dryas i n t e g r i f o l i a ) dominates the forb canopy cover, especially on dry sites where  58  Figure 13. The Elymus-Agropyron community. Note the dense cover of grasses and the l a c k of weathered forage.  Figure 14. The Elymus-Festuca community. Note the' moderately dense cover c r grasses and forbs i n c l u d i n g weathered forage of previous seasons growth.  59 s o i l s are not too acidic. Salix glauca  Shrubby cinquefoil (Potentilla f r u t i c o s a ) ,  and Betula glandulosa are common shrubs throughout the  community while bearberry (Arctostaphylos uva-ursi) commonly forms spreading mats on steep slopes and unstable s o i l s .  An abundance of weathered forage  from previous years growth r e f l e c t s the slow recycling of organic matter i n this alpine environment and only moderate u t i l i z a t i o n of the forage by sheep. (d) The Dryas-Festuca community The Dryas-Festuca community i s supported by Eutric Brunisols on exposed ridges or hogsbacks on the western slope of the mountain. I t occupies a t o t a l of 42 acres (17 ha) and i s characterized by a r e l a t i v e abundance of forbs and sparse cover of grasses (Fig. 15).  This community  i s described at three sites with elevations from 5,650 to 5,775 feet (1722 to 1759 m), an average slope of 26 percent and a southwestern aspect (Table 15).  Festuca scabrella dominates with low-growing perennial forbs  including Dryas i n t e g r i f o l i a , Polygonum viviparum, p r i c k l y saxifrage (Saxifraga tricuspidata) and moss campion (Silene acaulis) on t h i s cool, windy s i t e .  Elymus innovatus and Agropyron spp., common i n adjacent  communities are absent here, favouring warmer sites and more calcareous soils. (e) The Calamagrostis-Hierochloe community The Calamagrostis-Hierochloe community l i e s above the BetulaVaccinium  shrub association on the eastern alpine slope (Fig. 16).  Snow  cover i s more continuous and longer lasting than on southern and western exposures and Dystric Brunisols and Regosols have developed on acidic parent materials.  The plant community on this cool exposure with acidic  s o i l s (pH 3.5) has been described at four sites with slopes ranging from eighteen to twenty-eight percent and aspects ranging from southeast to north-  60 Table 13a. Major plant species C/F, f o r three sites i n the Elymus-Agropyron community Species  Study Sites  Grasses: Hordeae* Poa s p .  1  10A  10B  10C  C/F  C/F  C/F  80/100 1/55  74/100 2/30  67/100 23/95  1/30 tr/5  2/40  Oxytropis spp. Hedysarum alpinum  10/50 6/30  6/25 13/65  10/95 7/45  A c h i l l e a millefolium Epilobium angustifolium  4/55  8/75  16/95  Myosotis alpestris Galium boreale  14/80 6/35 2/30 8/75  3/50 10/95 3/65  Sile'ne repens  11/100  Poa rupicola Poa a r c t i c a  - '  3/80 2/40  B. Forbs:  C  7/100 7/90 1/30  5/90  Shrubs: Rosa acicularis P o t e n t i l l a fruticosa  3/30  0/0  3/30  0/0  0/0  0/0  " By ocular estimate Elymus innovatus  30%  95%  60%  Agropyron subsecundum  70%  5%  40%  "tentatively P. glauca  Table 13b. Shrub measurements and ground surface components for three sites i n the Elymus-Agropyron community Study Site  Species and Components A.  Shrubs:  Density  Rosa a c i c u l a r i s P o t e n t i l l a fruticosa B.  70 0  1  2.2  Av.Ht. Av.Crown diam(ihs) (ins)  6  0  3.7  I(%)  Density Av.Ht. Av.Crown I ( % ) Density Av.Ht. Av. diam(ins) (ins) (ins) Crown Diam. (ins)  0  0 2.2  40  15.3  15.4  100  4.5  20  0.06  6.5  3.9  13  9.5  Ground surface components (%) 24  5  16 63  28  Rock  10  1  9  Bare s o i l Crypogams  58 0  20 0  40 0  Living vascular plants Litter  1  Density  28  = No. of plants per square meter  CD M  Table 14a. Major plant species C/F for four sites i n the Elymus 'Festuca community  Species  Study sites 1C  1 B  A. Grasses: Elymus innovatus Festuca scabrella Poa arctica Festuca ovina Poa rupicola Tnsetum spicatum  C/F  '  ID  •C/F  C/F  C/F  "32/100 10/55 4/60 2/40 tr/3 2/43  27/93 13/58 1/30 tr/10 0/8 tr/18  19/98 10/88 3/63 0/0 1/15 1/28  * 33/100 46/100 2/145 6/80 3/30 1/45  tr/15  0/0  14/73  0/0  B. Sedges: Kobresia myosuroides C. Forbs: 15/45 13/33 Dryas i n t e g r i f o l i a Lupinus arcticus" 13/55 7/60 Polygonum viviparum 11/90 3/63 Mertensia paniculata 12/40 3/15 Saxifraga tricuspidata 3/33 6/65 Aeoniturn delphinifolium 7/83 1/35 Cerastium spp. 3/88 1/45 Pedicularis spp. tr/10 1/10 Galium boreale 2/20 1/28 Zygadenus elegans 2/38 0/0 Myosoti~alpestris 2/53 1/25 Gentiana spp. 1/48 2/50 Rumex acetosa 2/40 0/0 Polemonium acutiflorum 0/0 1/25 2/23 0/0 P o t e n t i l l a spp. " Includes 10-20 percent Agropyron subsecundum  0/0 8/55 1/20 4/43 7/38 4/58 1/28 0/0 3/75 1/28 1/20 2/25 1/25 0/0 1/35  17/80 6/70 15/100 1/30 3/40 2/90 2/30 4/65 0/0 3.30 1/60 0/0 1/30 2/40 0/0  CO  ro  Table 15a. Major plant species C/F f o r three sites i n -the Dryas-Festuca community Species and Components  A.  2C  ~C7F  C/F  ~C7F  10/53 4/10 2/48 2/85  10/80 1/78 2/55 1/38 1/15  8/75 5/98 1/45 1/73 1/15  1/5  1/38  3/30  15/95 7/98 5/100 2/10 3/53 1/20 1/23 1/40 1/28 1/18 2/40 1/70 1/25 1/15 1/58  15/93 6/93 5/9 8 6/33 3/53 5/13 3/43 2/33 2/43 3/18 1/63 2/58 1/20 1/30 1/43  Sedges:  Kobresia myosuroides C.  Study s i t e 2B"  Grasses:  Festuca scabrella Festuca ovina Poa a r c t i c a Trisetum spicatum Poa rupTcola B.  2A  Forbs:  Dryas i n t e g r i f o l i a Lupinus arcticus Polygonum viviparum Silene acaulis Saxifraga tricuspidata Cerastium spp. Oxytropis" spp. Aconitum~delphinifolium Polemonlum acutiflorum Saxifraga n i v a l i s SenecicTTugens Pedicular i s si Myosotis alpestris Luzula spicata Gentiana propinqua  19/100 5/88 6/100 3/60 4/63 1/23 2/33 2/73 2/58 1/13 i 1/68 1/55 1/18 1/40 1/63  CO CO  Table 15a. (continued)  Species and Components  Campanula uniflora Rumex acetosa P o t e n t i l l a spp. D.  2A  Study Site 2B"  2C  C/F 1/38 1/20 1/15  C/F 1/25 0/0 1/43  C/F 1/33 1/15 tr/28  2/3 5/5  6/18 0/0  1/9 1/9  Shrubs:  P o t e n t i l l a fruticosa Salix glauca  Table 15b. Shrub measurement and Ground Surface Components f o r three sites i n the Dryas-Festuca community Species  Study s i t e 2A 2 F Density (%) (No/M2)  2C  2E  2 2 Av. Average F Density Av. Average F Ht. crown d i a . (%) (No/M ) Ht. crown d i a . (%) In. (In) (In.) (In)  Density (No/M ) 2  Av. Average Ht. crown dia. In. (In)  A. Shrubs: P o t e n t i l l a fruticosa  10  tr  8  2.5  Salix glauca  10  tr  4  6  70  0.6  5.1  7.1  30  0.2  6  6  35  0.2  5  9  B. Ground surface components (%) Living vascular plant Litter Rock Bare s o i l Cryptogams  49 26 .9 0 16  •  41 35 4 7 13  37 29 12 0 22  CT) Cn  Figure 15. The Dryas-Festuca ccmmunitv on exposed r i d g e . Note the abundance of lew-growing D r y a s - i n t e g r i f o l i a and the sparse cover of grasses.  Figure 16. The CalaTasrostis-Hierochloe cennunitv. Note the absence of fcrbs and the prevalence of cryptogams on rock and ground s u r f a c e s .  67 Table 16a. Major plant species c/f and ground surface conditions for four sites i n the Calamagrostis-Hierochloe community Species and Components A. Grasses: Hierochloe alpina Calamagrostis lapponioa Festuca scabrella Poa spp.  5A  Study sites 5B 5C  5D  C/F  C/F  C/F  C/F  2/75 2/55 6/85 1/75  20/95 20/95 23/80 4/85  25/100 24/100 0/0 3/35  1/40  2/5  5/23 8/77 13/67 4/45  B. Sedges: Carex spp.  2/33  2/5  C. Forbs: Luzula spicata Artemisia norvegica Campanula lasiocarpa Silene acaulis Aconitum delphinifolium P o t e n t i l l a hyparctica Polygonum viviparum Polemoraum acutiflorum S t e l l a r i a longipes  3/55 3/58 0/0 4/13 2/55 1/28 1/38 1/13 1/70  1/80 tr/15 1/60 3/35 tr/80 1/70 1/70 1/40 tr/60  9/48 8/20 3/50  9/40 0/0 3/80  15/90 6/73 6/40 2/23 tr/30 tr/3 tr/3 tr/10 tr/43 .  24/95 0/0 tr/5 1/10 tr/20 tr/5 tr/5 tr/25 0/0  D. Shrubs: Vaccinium v i t i s - i d a e a Vaccinium leguminosae Salix polaris  0/0 0/0 0/0  2 F(%) = percent frequency by occurence i n 1/10M T = trace or less than 0.5%  plots  13/10( 0/0 0/0  68  Table 16b. Ground surface components (%) f o r four s i t e s i n the  5A  5B  Living vascular plant  25  35  29  29  Litter  29  12  29  35  Rock  4  1  9  5  Bare ground  3  6  0  0  39  46  33  31  Cryptogams  y ^ "5C U  5D  69 Table 17a. Major plant species C/F f o r two sites i n the Festuca-Dryas ccmmunity and one s i t e i n the Silene-Calamagrostis community  Species  Grasses: Festuca scabrella Festuca ovina Poa spp. Trisetum spicatum Calamagrostis lapponica Hierochloe alpina Poa arctica  3A  3B Study s i t e  4A  C/F  C/F  C/F  43/88 2/40 1/15 tr/8 0/0 0/0 0/0  63/95 6/45 5/30 1/20 0/0 0/0 0/0  1/35 1/35  1/8  8/40  35/82 12/63 4/47 13/44 3/47 1/30 1/10 0/0 3/40 5/10 2/47 1/38 2/24 0/0 tr/3 tr/12  5/30 13/70 20/100 8/75 13/95 7/85 2/10 0/0 8/65 tr/50 1/25 1/25 0/0 0/0 1/15 1/30  1/10 2/80 1/50 1/30  Sedges: Kobresia myosuroides  tr/5  Forbs: Dryas i n t e g r i f o l i a Lupinus arcticus Aconitum delphinif olium Senecio lugens Polemonium acutiflorum Gentiania propinqua Silene acaulis Luzula spicata" Mertensia paniculata Myosotis alpestris Polygonum viviparum Pedicularis spp. Solidago multriadiata Campanula spp. P o t e n t i l l a spp. Cerastium spp.  0/0 0/0 1/55 0/0 2/5 0/0 5/45 2/100 0/0 0/0 0/0 0/0 0/0 1/35 1/45 tr/15  Shrubs: P o t e n t i l l a fruticosa  7/35  0/0  0/0  70 Table 17b. Shrub measurements and ground surface components f o r two sites i n the Festuca-Dryas community and one s i t e i n the Silene-Calamagrostis community Species and Components  Study Site 3 A  ^  3 B  A. Shrubs:  I(%)  D  Av. Ht.(ins)  Potentilla . fruticosa  80  1  9.4  Av.Crown Dia.(ins)  I(%) D  12.4  0  I(%) D  0  0  0  B. Ground surface components (%) Living vascular plant  40  65  Litter  35  33  25  2  0  3  14  2  1  9  1  61  Bare s o i l Rock Cryptogams  •  10  71  Figure 17. The cryptogam-Salix community. Note the moss-lichen patches. The t a l l shrubs i n the immediate background a r e about 1 meter h i g h .  72 Table 18. Relative use of alpine plant communities at Nevis Creek as indicated by pellet group counts and the season of their main use as determined from observations. Plant Community  Extent No.per No. sample Main Season Acres (hectares) sq.yd.(per M ) plots (3M ) of Use  Elymus-Agropyron  15  Festuca-Dryas  19  Elymus-Festuca  60  Dryas-Festuca CalamagrostisHierochloe  2  (6.1)  2  3.790 (4.533)  30  Winter and spring  0.911 (1.090)  20  Summer  (24.3)  0.591 (0.707)  80  Winter and spring  42  (17.0)  0.504 (0.603)  60  Winter  190  (76.9)  0.278 (0.332)  60  Summer  Silene-Calamagrostis 3  (1.2)  0.276 (0.330)  10  Summer  Betula-Vaccinium vitis-idaea  142  (57.5)  0.254 (0.310)  30  Summer  Betula-Vaccinium uliginosum  90  (36.4)  0.192 (0.230)  20  Summer  (7.7)  Table 19. Net productivity and combined protein levels of oven-dried forage from the three most important plant communities f o r wintering sheep Forage Weight Plant Community  Site  2. Elymus-Agropyron 10A 10B IOC  3. Elymus-Festuca  4. Dryas-Festuca  1A IB 1C ID  2A 2B 2C  Altitude Slope Exposure  Cg/m i S.E.) 1969 2  CLbs/acre) 1969 1970 Fall/70  C r u d e  1970  ^ Sp/70 o  t  5120-5150 52-59% S  239.2T7.3 139.9 8.9 163.6-7.4  2081.1 9.46 1243.0 9.87 1465.0 10.53  Mean Av.  180.9-7.9  1596.0  5325-55— 40-53% SE-SW  84.9-10.0 953.5 152.9 13.4 603.3 113.9-12.0 759.7 141.3-14.9 1033.8  ,753.6 8.85 1371.2 8.82 1021.7 10.91 1264.7 8.34  4.43 4.60 6.23  Mean Av. 94.1^80  123.3-12.6  836.3  9.23  5.08  5650-5775 26% SW  36.9-1.9 36.5r3.4 53.0-2.8  384.6 326.5 328.6  328.4 324.1 471.3  7.79 8.56 7.51  7.04 6.63 7.09  Mean Av. 77.7-7.6  42.1^2.7  346.6  374.6  8.07  6.92  t  T  1102.8  9.95  e  i  n %  Diff  12.09 6.83 6.89  lbs/acre F a l l 1970  196.87 122.68 154.26  8.60 -13.6  157.94 66.69 120.94 111.47 105.48  -44.9  101.45 25.58 27.74 35.39  -14.3  29.57  74 east (Table 16). Study s i t e altitudes ranged from 6,000 to 6,300 feet (1829 to 1919 m). This community occupies 190 acres (77 ha) and i s dominated by the grasses: Calamagrostis lapponica, alpine holy grass (Hierochloe alpina) and Festuca scabrella, the l a t t e r species being r e l a t i v e l y more abundant i n swales and seepage s i t e s .  With the exception of grass-like  spike woodrush (Luzula spicata), forbs are poorly represented. Lowgrowing Vaccinium v i t i s - i d a e a and V_. uliginosum are common shrubs on betterdrained sites while crowberry (Fjripetrum nigrum), common juniper (Juniperus communis) and heather (Cassiope tetragona) occur on protected sites within the grassland community. Cryptogams are the main ground surface cover component, averaging 37 percent at the four sites studied, (f) The Festuca-Dryas community The Festuca-Dryas community occupies nineteen acres (7.7 ha) on a steep southwestern exposure between 5,750 and 6,400 feet (1753 and 1951 m) altitude.  I t was studied with paired transects at two sites having slopes  of 56 and 48 percent (Table 17).  The community i s supported mainly by  r e l a t i v e l y deep, dark coloured organic s o i l s developed on calcareous colluvium and characterized by abundant basic seepage waters.  The species  composition of this plant community i s similar to that of the Dryas-Festuca type immediately below, especially for the major plants; Festuca scabrella, Dryas i n t e g r i f o l i a and Lupinus arcticus.  However, i t i s a much more  productive community as shown by the percent canopy coverage which averaged 85.5 percent as opposed to 31.6 percent f o r the three common dominants. I t d i f f e r s i n other respects also, i n that i t includes species such as Mertensia paniculata, large-flowered anemone (Anemone parviflora ). Saxifraga tricuspidata, which i s w e l l represented on the drier Dryas-Festuca s i t e i s lacking i n this community.  75 (g) The Silene-Calamagrostis community The Silene-Calamagrostis community occupies only three acres (1.2 ha) on the narrow, undulating ridge of the mountain top which l i e s between 6,300 and 6,675 feet (1919 and 2034 m) a l t i t u d e . Climatic conditions are harsh, with early freezing temperatures, strong drying winds and accumulated d r i f t snow which remains on parts of the s i t e w e l l into the month of June. Dystric Brunisolic s o i l s developed on acidic sandstone support an inpoverished community of grasses and low-growing forbs which was studied at one s i t e using paired transects (Table 17).  Silene acaulis,  Calamagrostis lapponica, Luzula spicata and Jacobs ladder (Polemonium acutiflorum) were the only vascular species having a canopy cover exceeding one percent.  Shrubs were lacking and lichens and mosses were the main  ground surface components., t o t a l l i n g 60 percent at the s i t e studied. (g) The Gryptogam-Salix community This community, which was studied on the south side of the Nevis v a l l e y , occupied 20 acres (8 ha) on alpine slopes with a northern exposure. Because i t was not used by sheep, i t was investigated only at a reconnaissance l e v e l .  On the cold, northern alpine slopes, Humic Gleysols  containing frozen layers support a hydrophylic plant association of low productivity.  The vegetation consisted largely of mosses and lichens  including: Sphagnum rubeHum, S. nemoreum, Pholia sphagnicola, Halacomium palustre and Cladonia a l p e s t r i s .  Common vascular associates included:  retted willow (Salix r e t i c u l a t a ) , northern dwarf willow (S.polaris), Dryas i n t e g r i f o l i a , dwarf h o r s e t a i l (Equisetum scirpoides), Festuca scabrella and Lupinus arcticus.  Thickets of Betula glandulosa, Salix glauca, and  hairy willow (S. lanata) occur on better-drained sites within t h i s community, (Fig. 17).  This community, which has cognates i n the tundra of higher  latitudes, appears to be spreading into communities where grasses, sedges  76 and shrubs are more common (V.C. Brink, pers. comm.).  5.2.3. Importance of plant communities to sheep Observations indicate that stone sheep i n the northern f o o t h i l l s depend almost exclusively on alpine vegetation, f o r t h e i r forage requirements. Low elevation grasslands are limited to fine textured a l l u v i a l s o i l s i n the valley bottoms or/serai grasslands which tend to be rapidly invaded by shrubs. In summer, the sheep have a wide choice of feeding areas and they grazed most of the alpine plant communities distributed over about 560 acres (2.27 ha) at one time or another during t h i s season.  Feeding sheep were  observed most frequently i n the Calamagrostis-Hierochloe and Betula-Vaccinium v i t i s - i d a e a communities on the east slope and i n the Festuca-Dryas community, high on the west slope of Nevis Mountain during the summer. Use of these areas was severely limited i n winter by snow cover. The results of p e l l e t group counts, presented i n Table 18 provides a measure of the r e l a t i v e use of the alpine plant communities.  The Calamagrostis-Hierochloe and Betula-  Vaccinium v i t i s - i d a e a communities are extensive, and though p e l l e t groups counts indicate they• ranked only sixth and seventh respectively i n terms of use per unit area, they ranked second and t h i r d i n terms of use by t o t a l area.  The Festuca-Dryas-community,  only 19 acres (7.7 ha) i n extent, ranked  only sixth i n terms of use by t o t a l area, but i t ranked second i n terms of area use per unit /indicating that i t was highly favoured by sheep during the summer months. In winter, sheep are r e s t r i c t e d to exposed places where snow cover i s reduced by exposure to sun and wind. the Elymus-Agropyron  At Nevis Creek the sheep mainly used  and Elymus Festuca communities on slopes with a southern  aspect and the Dryas-Festuca community on windswept ridges with a western  x  77 aspect i n winter.  Altogether these communities occupied about 117 acres  (47 ha) on Nevis Mountain. The results of p e l l e t group counts (Table 18) indicate that the Elymus Agropyron community received the heaviest use per unit area and, i n spite of i t s limited extent, was used more by sheep than any other alpine plant community. This community was also used heavily i n the spring since the f i r s t new growth of spring occurs here but i t was r a r e l y used during the summer months. The Elymus-Festuca and Dryas-Festuca communities respectively ranked t h i r d and fourth i n use per unit area and fourth and f i f t h i n terms of use per t o t a l area. These communities were used mainly i n the winter, but to a lesser extent, i n spring, summer and f a l l as w e l l .  Food habits of the sheep are discussed more s p e c i f i c a l l y i n  section 6.2.2. 5.2.4.  Forage production and quality on the winter range  Productivity and percent crude protein results from the three main plant communities used by wintering sheep are shown i n Table 19. (a) Productivity The ElyiiMs-Agropyron community was the most productive on the winter range, yielding an average of 1,596 pounds of oven -dried forage per  acre (1,789 Kg per ha) i n 1970.  Grasses made up more than 80 percent  of t h i s amount by weight. The Elymus-Festuca community yielded 1,103 pounds per acre (1,236 Kg per ha) or about 70 percent of the amount yielded by the l a t t e r community while the Dryas-Festuca community yielded only 375 pounds per acre (420 Kg per ha) or less than a quarter of that yielded by the  Elymus-Agropyron community. Grasses made up 70 percent and forbs 30  percent by weight i n the Elymus-Festuca community. These class proportions were reversed i n the Dryas-Festuca community where Lupinus arcticus contributed the most f o r forbs.  78 Although the Elymus-Agropyron community produced the most, and the Dryas-Festuca community Festuca  the least forage on a unit area basis, the Elymus-  community produced about 63 percent of the t o t a l forage produced  by these three p r i n c i p a l winter range communities. The Elymus-Agropyron community produced about 23 percent and the Dryas-Festuca community about 15% of this amount. (b) Forage quality As shown by the results i n Table 19, percent crude protein was highest f o r the f a l l y i e l d samples from the Elymus-Agropyron community which averaged 9.95 percent as compared to 9.23 percent f o r the ElymusFestuca community and 8.07 percent f o r the Dryas-Festuca community.  On  a t o t a l area basis, these respective communities produced f a l l yields of about 2370 pounds (2,656 kilograms), 6087 pounds (6,823 Kg) and 561.8 pounds (628.8 Kg) of crude protein.  The decline i n crude protein content from  f a l l y i e l d samples to spring samples of weathered vegetation was 13.6 percent for the Elymus-Agropyron community, 14.3 percent f o r the Dryas-Festuca community and 44.9 percent f o r the Elymus-Festuca community.  The 13.6  percent decline i n crude protein indicated f o r the Elymus-Agropyron community i s a low estimate because plots at s i t e 10A were clipped l a t e , after spring growth had begun.  The actual decline i n crude protein f o r  t h i s community was probably about 30 percent. 5.2.5. Forage u t i l i z a t i o n and wastage on the winter range The removal of forage by grazing sheep and wastage due to weathering i n the three p r i n c i p a l plant communities on the winter range during the winter of 1969/70 i s shown i n Table 20. The forage removed by grazing sheep includes that unknown portion lost through breakage due to trampling or pawing to remove snow.  79  Table 20. Forage removed by wintering sheep and weathering i n the p r i n c i p a l winter range communities during the winter of 1969/70 Plant Community  Net Productivity  Elymus-Agropyron  Forage removed by weathering lbs/acre % forage produced  1596  Forage removed by sheep lbs/acre %  -  -  Elymus-Festuca  987  128  13  188  Dryas-Festuca  482  222  46  46  19 9.5  Total forage removed lbs/acre \ 1433  90  316  32  268  55.5  The results i n Table 20 show that 90 percent by dry weight of the forage produced by the Elymus-Agropyron community was removed over the winter period (Figs. 18 and 19). Although the proportion lost due to weathering was not measured, i t i s not expected to have exceeded the amount (13 percent) removed by t h i s means i n the adjacent Elymus-Festuca community. Thus, about 80 percent of the forage produced by the Elymus-Agropyron community and only 19 percent of that produced by the Elymus-Festuca community was removed through grazing. Although 55 percent of the forage produced by the Dryas-Festuca community was removed over the winter period, only 9.5 percent was removed by grazing sheep, the other 46 percent being removed by weathering on this windswept s i t e .  On the basis of forage removed per unit area, the  Elymus-Agropyron community provided about 57 percent, the Elymus-Festuca community 38.5 percent and the Dryas-Festuca community 4.5 percent by dry weight of the t o t a l forage removed by wintering sheep from these three plant communities.  80  5.2.6. Discussion While the description of plant communities below treeline i s s u p e r f i c i a l , i t was meant to be a simple, rather than a detailed account of that portion of the study area which, l i k e the alpine habitat, is poorly documented i n the l i t e r a t u r e .  Much of the climax vegetation  below t r e e l i n e has been replaced with seres dominated by willow, glandular birch and lodgepole pine.  Succession proceeds slowly at this l a t i t u d e  even i n the f i r e produced seres below t r e e l i n e .  However, while some serai  communities p e r s i s t with l i t t l e change for long periods of time, others are characterized by a rapid t r a n s i t i o n .  For example, most serai grasslands  are rapidly invaded by shrubs which re-established quickly and soon reach or exceed t h e i r former abundance because of t h e i r a b i l i t y to reproduce vegetatively from undamaged root stocks. Alpine plant communities have been influenced l i t t l e by f i r e except near t r e e l i n e .  Coniferous trees were slowly invading lower l i m i t s of the  Betula-Vaccinium shrub associations on east and west-facing slopes and the Populus community was invading the lower Elymus-Agropyron and Elymus-Festuca communities on the south-facing slope of Nevis Mountain. At higher elevations, alpine plant communities are essentially i n climax or sub-climax condition.  Even the Elymus-Agropyron community can be  considered a stable sub-climax which has developed through centuries of heavy seasonal grooming by the native sheep. Even i n essentially stable plant communities uninfluenced by f i r e , however, there are v i s i b l e trends indicating long-term vegetation change. The persistent spread of mosses and lichens on to grassland and shrub communities of cool exposures, and of shrubs on to grasslands of warm slopes and valley terraces are examples of such trends.  In the alpine,  81  trees and shrubs are eliminated from unprotected places but stunted alpine f i r and low shrubs such as willows, glandular b i r c h , blueberries and  crowberry  occur on sites protected from severe frost by a blanket of snow. As trees and shrubs cause d r i f t i n g snow to accumulate, they create a microclimate favourable to their further spread.  The slow cumulative d r i f t of shrubs  i s p a r t i c u l a r l y apparent as spreading patches of white willow and glandular birch on warm alpine slopes and valley grasslands. Although alpine plant communities were investigated i n much greater depth than those below t r e e l i n e , the vegetation showed a high degree of complexity and time limited the intensity and therefore the adequacy of sampling i n t h i s study.  The results of f l o r i s t i c studies are comparable  for a l l plant communities studied i n d e t a i l even though the adequacy of sampling varies.  Also, the restricted random design of the macroplot method  allows f o r the testing of between as w e l l as within plot v a r i a b i l i t y .  Sampling  adequacy was tested during the study by plotting coverage and frequency percentage of major and minor taxa against the number of plots studied i n a given stand (Daubenmire, 1959). From t h i s , i t was apparent that the l e v e l of sampling which time permitted was adequate f o r major but not for minor taxa i n any given community. Thus, the results are less than descriptive for plant communities with a large number of minor species than f o r communities which contained r e l a t i v e l y fewer minor species. A l l of the alpine plant communities on Nevis Mountain were used by sheep although use varied seasonally and i n intensity.  P e l l e t group counts  and observations indicated that although sheep used the CalamagrostisHierochloe and Betula-Vaccinium v i t i s - i d a e a communities extensively during the summer, they favoured the Festuca-Dryas community which received the  82  heaviest use per unit during this period. Three plant communities limited t o 117 acres (45 ha) on warm southern and western exposures provided c r i t i c a l winter range f o r the sheep and were investigated i n greater depth. Productivity estimates f o r these communities were based on a limited sample of f a l l forage y i e l d s .  The yields actually  provide a low estimate of net productivity since only the a e r i a l portion of plants more than one half-inch above ground l e v e l was included and because the forage was clipped at late maturity when some grasses had reached the seed dissemination stage and loss by shattering had occurred.  However, the  results provide a reasonable estimate of net primary productivity and of forage available f o r the sheep a t the onset of winter.  The results are  comparable with estimates from alpine environments i n other parts of the world including those of the more southern latitudes of B r i t i s h Columbia (Brink, V.C., A. Luckhurst and D. Morrison, 1972). The variation i n yields from different slopes and aspects emphasizes the correlation between s o i l s , climate and vegetative productivity.  Crude  protein content of forage from the alpine winter range was t y p i c a l l y high and i t s decline over the winter period was low compared with levels i n native forage plants from lower elevations and latitudes (Johnson and Bezeau, 1968). The crude protein results indicate that only forage from the Elymus-Agropyron community, which had the highest crude protein levels i n the f a l l , maintained average crude protein levels (8.60 percent) within the minimum range of 7.0 to 9.5 percent recommended by the National Research Council (1957) f o r growth and gestation i n domestic sheep.  However, crude protein estimates f o r weathered  forage from this community are known to be high and the highest actual l e v e l for weathered forage appears to be the 6.92 percent recorded f o r the DryasFestuca community which had the lowest crude protein content i n i t i a l l y .  83  Figure 18. C l i p p i n g grazed forage p l o t s a t s i t e No. IDA i n the Elymus-Agropyron community. Note the sparseness of remaining forage. Photo taken May 16/70.  Figure 19. A temporary enclosure at S i t e 10A. Note the productive growth, mainly grasses. Photo taken J u l y 31/70.  84  Buebenik (cited by D i r c h l , 1963) reported that a diet containing about 7 percent crude protein met the minimum winter requirements f o r mouflons (Ovis musemon). Although crude protein content of weathered forage from the p r i n c i p a l (Elymus-Festuca) community on the winter range averaged only 5.08 percent, t h i s i s comparable with levels reported f o r forages from native sheep ranges i n more southerly latitudes (Demarchi, D.A. 1970, Demarchi, R.A., 1968, and Johnson and Bezeau, 1968).  85  6. STONE SHEEP 6.1 Methods Seasonal movements, distribution and population characteristics of stone sheep were determined from a e r i a l and ground observations.  Sheep  were c l a s s i f i e d on the basis of horn size, body size and sex i n eight classes (Geist, 1968). Ewes over 2 years old cannot be separated on the basis of age and were grouped as mature ewes. Rams, however, were separated on the basis of horn size into four age classes which included animals predominantly of the following ages: Class I rams, 2 t o 3 years old; Class I I rams, 3 t o 6 years old; Class I I I rams, 6 to 8 years o l d , and Class IV rams, 8 years and older. Productivity estimates were determined from early summer ewe and lamb ratios while changes i n sex and age ratios through time provided a r e l a t i v e measure of juvenile and adult mortality. Food habits were determined by rumen sample analysis, by recording grazed and ungrazed plant species i n a t o t a l of f i f t y 0.1 square meter sample plots and by observing feeding animals.  Five 1-quart (1.136 L) rumen samples were collected from sheep  feeding on the winter range. These were washed and screened and a volumetric estimate of the i d e n t i f i a b l e material was determined by water displacement. Plants were i d e n t i f i e d by gross vegetative characteristics with the a i d of a dissecting scope and a reference plant c o l l e c t i o n .  A 500 ml subsample  was analyzed by the point analysis method described by Chamrad and Box (1964).  Grasses and sedges, grouped as a single class i n the volumetric  analysis, were i d e n t i f i e d , as f a r as possible, t o species i n this analysis. Only one of the f i v e rumen samples was analyzed by t h i s method because, although i t provided some worthwhile data, i t was time consuming and limited  86 by problems i n sampling and i d e n t i f i c a t i o n . A s o i l sample from the mineral l i c k at Nevis Creek and an unrelated sample from the sheep summer range were analyzed f o r major elements by the U.S.D.A. s o i l testing laboratory, Ohio State University, Columbus, and f o r minor elements by the Geology Department, University of B r i t i s h Columbia, Vancouver. Causes of mortality as inferred from f i e l d observations are discussed generally i n terms of competition f o r forage and the incidence of injury, parasites, disease and predation, including hunting. Additional information was obtained from autopsy and examination of animals shot f o r study purposes or by hunters and from hunter harvest records. 6.2 Results 6.2.1 Seasonal movements and d i s t r i b u t i o n As indicated i n Section 5.2.3 stone sheep i n the northern Rocky Mountains occur generally above t r e e l i n e .  Typically, they are segregated  into ram and ewe:juvenile groups or bands which tend to occupy d i s t i n c t "home ranges" through most of the year. During the rut, i n late f a l l and early winter, the rams leave t h e i r summer range to v i s i t ewe-juvenile ranges where they spend a greater or lesser part of the winter. The sheep range on Nevis Mountain was essentially a ewe-juvenile home range-. I t supported few rams older than yearlings and none older than three years except i n late f a l l and winter when rams came to breed and to graze on the exposed slopes where snow depths were reduced. major influence on the d i s t r i b u t i o n of sheep.  Winter snow cover had a With the f i r s t snows of  autumn, the sheep moved down from the high summer range to feed on lower alpine slopes with a southern or western exposure.  As winds swept the  higher slopes and ridges free of snow, the sheep tended to move up and  87 u t i l i z e the often sparse vegetation of these s i t e s .  This response was  very noticeable i n parts of the f o o t h i l l s where high windswept suirimits were more extensive and thus more important to wintering sheep than on Nevis Mountain.  On Nevis Mountain, the sheep spent much of t h e i r time on  south or west facing slopes and ridges below 5,700 feet (1,737 m) a l t i t u d e . The sheep remained on the lower south facing slopes t o feed on the f i r s t green forage of early spring.  As spring progressed, the sheep gradually  spread out feeding on the weathered forage and new spring growth of higher altitudes and cooler exposures.  During late May and early June most of  the ewes moved on to steep rocky t e r r a i n t o have t h e i r lambs. While ewes with newborn lambs tended t o remain near steep, rocky t e r r a i n , those without formed groups that moved more freely over the slopes which were rapidly becoming more snow-free.  During the summer the sheep grazed widely  over t h e i r alpine habitat, generally at altitudes above 5,500 feet (1,676 m) but occasionally descending to t r e e l i n e .  The summer pattern of feeding,  resting and nursing was interrupted by frequent v i s i t s t o the mineral l i c k s i n the valley below. The l i c k s were used most heavily i n late spring and early f a l l .  They were used by sheep of both sexes and almost 100 sheep  were seen there at times, some from ranges at least 10 miles distant. Occasionally on the way t o or from the l i c k s , sheep v i s i t e d the home ranges of adjacent bands, sometimes remaining f o r a week or more. 6.2.2 Foods and minerals Spring forage preferences as determined from f i v e spring feeding sites i n the Elymus-Agropyron  community are presented i n Table 21. In this table,  the percentage frequency of occurrence refers to the percentage of plots i n which a species occurred out of a t o t a l of 50 plots.  The percent grazed  refers to the percentage of plots i n which a species was grazed out of the  88  t o t a l number i n which i t occurred. An importance index was calculated from the raw data by multiplying the number of plots i n which a species was grazed by i t s frequency of occurrence and the results doubled to give an upper l i m i t of 100. The species l i s t e d i n Table 21 supported new spring growth i n a l l plots where they occurred with the exception of Galium boreale which supported new growth i n 10 out of the 15 p l o t s . i n which i t occurred, and Rosa a c i c u l a r i s which supported no new growth.  The lack of new spring  growth may account i n part f o r the low frequency of grazing on these species since the sheep appeared to be selecting f o r new green forage at the time. Table 21 shows that grasses, mainly Elymus innovatus, Agropyron subsecundum and Poa spp., occurred frequently and were grazed frequently, giving t h i s forage class a combined importance rating (131.6) almost four and one half times greater than that f o r a l l other species recorded (29.7).  Sedges were  represented mainly by Kobresia myosuroides which had a grazing frequency of 83.5 percent but rated less than 1 i n the importance index because i t occurred i n only 10 percent of the plots.  Carex sp. which was grazed with  a hundred percent frequency i s not l i s t e d i n Table 21 because i t occurred i n less than 10 percent of the plots.  With the exception of Oxytropis sp.,  which was assigned an importance rating of 26, a l l forb species rate less than one i n the importance index.  Several species, including A c h i l l e a  millefolium, with a 36 percent frequency of occurrence, were not grazed even though they occurred commonly. Forage species preferences were not measured s p e c i f i c a l l y during the summer when the sheep grazed on a wide range of alpine plant communities as indicated i n section 5.2.3. Observations indicate that grasses and sedges made up a major part of t h e i r diet with forbs being u t i l i z e d to a  89  Table 21  Percent frequency of occurrence and spring grazing of plants i n the Elymus-Agropyron community  Species  Percent occurrence  Percent grazed  Importance Index  Grasses and sedges: 'bfordeae  100  98 .  98  Poa spp.  80  68.5  33.30  Festuca scabrella  14  22  0.28  Kobresia myosuroides  10  83.5  0.80  52 40 36 30 28 24 24 24 24  29 13 0  Forbs: Oxytropis sp. Myosotis alpestris A c h i l l e a millefolium Galium boreale Erigeron sp. Zygadenus elegans Gentiana sp. Pedicularis sp. Cerastium sp. Mertensia paniculata Antennaria sp. Solidago multiradiata Fragaria virginiana Rumex acetosa Saxifraga cernua Shrubs: Rosa a c i c u l a r i s  14 14 12 10 10 10  14  ^Elymus innovatus and Agropyron subsecundum  6.5 13.5 27.5 0 0 0 0 0 0 0 0 0  26.0 0.80 0 0.3 0.6 1.96 0 0 0 0 0 0 0 0 0  90  lesser but significant extent.  These forage classes were sought out by  the sheep even when they fed on sites dominated by shrubs. Festuca scabrella, F. ovina and Poa spp. were grazed heavily by the sheep when feeding i n the Festuca-Dryas community which they used frequently i n summer. Often the sheep seemed to show l i t t l e s e l e c t i v i t y i n t h e i r feeding except i n t h e i r choice of plant communities, grazing randomly on whatever herbaceous vegetation was available.  At other times, they showed a high  degree of s e l e c t i v i t y and this became more apparent as the end of the summer growing season approached.  During an early snowstorm i n August, the  sheep pawed through 4 inches of snow t o feed on low-growing herbaceous plants i n the Elymus-Agropyron community, but did not feed on shrubs, a r c t i c lupine or the coarse seedheads of lyme grass or bearded wheatgrass which protruded abundantly above the snow. In late summer and f a l l , the sheep browsed more frequently, mostly on the leaves of Salix glauca, and the leaves and f r u i t s of Vaccinium uliginosium, V. Vitis-idaea and Ax'ctostaphylos uva-ursi.  They were also •  observed seeking out the flowering heads of certain plants such as C a s t i l l e j a miniata and P o t e n t i l l a fruticosa during t h i s season. The rumen analysis results presented i n Table 22 are from sheep collected on the winter range at Nevis Mountain and provide a measure of winter forage preferences.  The f i r s t three rumen samples i n the Table are  from sheep k i l l e d i n January, the l a s t two from sheep k i l l e d i n the f a l l . The sheep had been feeding mainly i n the Elymus-Festuca and Festuca-Dryas plant communities when they were k i l l e d . The results i n Table 22 confirm the importance of grasses i n the sheeps' diet.  Grasses and sedges averaged about 90 percent by volume of the  material i n the rumen samples and sedges probably represent a minor component  91 Table 22  Rumen sample analysis from 5 stone sheep collected on the winter range at Nevis Creek  Rumen Sample la lb 2 3 Est.% Value % Volume  Food Item  '•Av.% Volume Occurrence  *Av.%  Grasses 6 Sedges: Festuca scabreUa Poa sp. Kobresia myosuroides Festuca ovina ^Hordeae Carex sp. Unidentified  43.0 16.0 3.5 3.0 1.5 0.5 30.0  Total  97.5  85.5  97  98.5  0.5 0 0 0 0 0 tr  1.5 0 0 0 0 0 tr  tr 0 0 0 0 0 tr  0.5  1.5  tr 0 0 0 tr tr tr tr 0.5  Forbs: Dryas i n t e g r i f o l i a Leguminosae Polemonium sp. Silene acaulis Polygonum viviparum Saxifraga tricuspidata Unidentified Total  62  95  87.6  100  5.0 0 0 0 tr tr tr  2.0 tr tr 0 tr 0 tr  1.0 1.5 0 1.0 0 0 1.0  1.5 tr tr tr tr tr tr  80 40 20 20 60 20 100  0.5  5.5  2.5 4.5  3.0  48.5  1.5 0 0 tr tr tr tr tr  tr 2.5 tr tr tr 0 0 tr  tr 0 0 0 tr 0 0 tr  26.5 1.5 5.5 0 1.5 0.5 1.5 t r 0 0 0 0 0 0 tr tr  6.0 1.5 0.5 0.5 tr tr tr tr  100 40 60 80 60 40 10 100  2.0  3.0  0.5  35.0 2.5  8.5  86  Shrubs: 2Salix spp. Vaccinium v i t i s - i d e a Arctostaphylos uva-ursi Vaccinium uliginosum Betula glandulosa P o t e n t i l l a fruticosa Juniperus communis Unidentified Total  " Average values determined from rumen samples l b t o 5 ^Elymus innovatus and Agropyron sp. "Salix glauca, S_. polaris and S_. r e t i c u l a t a  92  since they were a minor component i n the plant cover of the winter range communities.  The results include the analysis of sample one by the point  analysis method (la) as well as the water displacement method ( l b ) .  The  point analysis results indicate that Festuca scabrella i s an important forage species since i t made up an estimated 43 percent or more by volume of the rumen content of a sheep k i l l e d while feeding i n the Elymus~F_esJnjca plant community. Poa sp.  also appears to be important but the significance  of the results i s questionable f o r a l l other species since the estimated percent volume was much less than that of the unidentifiable material.  In  addition to confirming that the sheep are primarily grazers, the rumen analysis results also confirms the r e l a t i v e l y greater importance of shrubs i n t h e i r f a l l diet.  Grasses and sedges averaged 78.5 and shrubs 19 percent  by volume of the f a l l rumen samples while these respective classes averaged 95.6 and 2 percent by volume of the winter rumen samples. When sheep v i s i t e d the mineral l i c k s , they ate a l l u v i a l s o i l from the creek bed and drank water seeping through fractured Buckinghorse shale which borders Nevis Creek.  The analysis results of a s o i l sample from the  l i c k and an unrelated control sample are presented i n Appendix 5.  The  analysis results show the sample from the l i c k was lower i n phosphorus and calcium and showed no significant difference i n the amounts of ten other elements.  However, the l i c k sample contained sodium i n the amount of  78.9 l b s . per acre as opposed to only 37.2 l b s . per acre i n the control sample. 6.2.3 Population structure The percentage composition of stone sheep populations as determined from c l a s s i f i e d counts from a major portion of the Northern Rocky Mountains and f o o t h i l l s are presented i n Table 23.  This table includes counts taken  93  i n summer and winter during the period from January, 1969 to March, 1971. The Nevis Mountain count represents a mean t o t a l of the best counts determined for each age class at Nevis Mountain during the two summer and two winter periods of the study.  A l l others represent single counts  within which there was l i t t l e or no duplication. The averages i n Table 23 show that f o r every 100 ewes there were 63 lambs and 42 yearlings (n = 765).  The results also indicate an average  r a t i o of only 51 mature rams per hundred ewes (n = 591).  The r a t i o of  rams to ewes i s too low and serves to show how d i f f i c u l t i t i s to get representative male:female ratios f o r sheep which segregate sexually (see section 6.3).  In order to describe the ram segment of the population and  provide more r e a l i s t i c ram:ewe r a t i o s , the results of three selected counts are presented i n Table 24.  The counts i n Table 24 were selected because  they were the most extensive and inclusive i n terms of ewe:ram ranges. Also, they were conducted by helicopter which permitted more complete coverage than ground counts and more accurate i d e n t i f i c a t i o n than counts from fixed-wing a i r c r a f t . In the results from the Muskwa-Prophet River count, Class I I I and Class IV rams, which were grouped i n i t i a l l y , are separated on the basis of ratios determined f o r the other two counts i n Table 24. According to the results i n Table 24, there were 19 or 20 Class I , 25 or 26 Class I I , 25 Class I I I and 10 or 11 Class IV rams f o r a t o t a l of about 80 adult rams per hundred adult ewes. Thus, the age class structure of rams was 24.5 percent Class I , 32 percent Class I I , 30.5 percent Class I I I and 13 percent Class IV.  The number of Class I rams seems dispropor-  tionately high, especially i n the Stone Mountain-Sentinel Range count. This i s believed to be due largely to a poor representation of the last  Table 23. Percentage composition of stone sheep populations i n the northern Rocky Mountains. observed i s shown i n brackets beside the percent figure f o r each class. Area  IV  10(27)  15.5(42)  0  (10)  279  3(1)  15(5)  15(5)  0  (8)  40  28.5(57) 15.5(31)  8(16)  10.5(21)  9(18)  (75)  275  28.5(28)  46.5(46) 20(20)  4(4)  106  Tuchodi R. Mar. (Helicopter) 1971 Stone Mountain Mar.  29.5(12)  46.5(19) 22(9)  2.5(1)  (Helicopter)  19.5(36)  46(85)  17.5(32)  5.5(10)  5.5(10)  5.5(10)  23(26)  45(51)  18.5(21)  7(8)  2(2)  29(11)  48(19)  20.5(8)  2.5(1)  1.5(1)  (234) 24  (376) 38  (156) 16  (Helicopter)  Lambs  Ewes  Yearlings  I  24(65)  33(89)  11.5(31)  6(15)  27(7)  31(10)  12.5(4)  24.5(49)  II  Unclassified Totals  I l l ...  MuskwaProphet R.  Date  The actual number  Jan. 1969  MuskwaProphet R. Jan. (Ground) 1969 Nevis CreekRichards Cr. (Helicopter July and ground) 1969 Nevis CreekBesa R. Aug. (Ground) 1970  1971  1(1) -  4(8)  -  -  (7)  -  -  -  41  1(2)  (8)  193  2.5(3)  2(2)  (5)  118  0.5(1)  0.5(1)  Sentinel Range Mar. (Helicopter)  1971  Nevis Mtn. Av. (Helicopter 8 Ground) Total No. Mean percentage Mean No. per 100 ewes  5 3  4 2  (56) 5.5 14.5  (67) 7 18  (79) 8 21  (13) 1.5 4  42 (113)  1094 ^  Table 24. Rams per 100 ewes from selected c l a s s i f i e d counts (n = 194)  Area  Age Class II III  Time  I  Winter 1968/69  18  30.5  Richards CreekNevis Creek (Ground and Helicopter)  Summer 1969  28  Stone MountainSentinel Range (Helicopter)  Winter 1969/70  MuskwaProphet (Helicopter)  Mean Total  IV  Totals  33  14  95.5  37  31.5  14  110.5  13  8.5  9  3.5  34.5  19.5  25.5  24.5  10.5  80.0  96 three age classes as discussed i n Section 6.3. The sheep range on Nevis Mountain supported a small band of ewes and juvenile sheep t o t a l l y about 50 animals. The results of c l a s s i f i e d counts from Nevis Mountain are presented i n Table 25. The results i n Table 25 represent the best c l a s s i f i e d count obtained for each class over the summer periods while the winter counts are from a single census made by helicopter i n January, 1970, and March 1971.  Since  rams older than 2h years are only infrequent v i s i t o r s to t h i s range, they were not included i n the results i n Table 25. According to the results i n Table 25 there was an average of 61 lambs and 43 yearlings per hundred ewes. This compares closely with the average lamb:ewe (63:100) and yearling:ewe (42:100) ratios obtained f o r counts taken over a greater area of the Northern Rocky Mountains (see Table 23). 6.2.4  Productivity  The r a t i o of lambs to ewes from early summer counts i n the study area provides a r e l a t i v e measure of productivity (Table 26). The results i n Table 26 show an average observed lamb:ewe r a t i o of 74:100 indicating a high birthrate and low mortality i n the f i r s t few weeks of l i f e . Calculated ewe:lamb ratios were determined by subtracting 20 percent 2-year old females from the t o t a l mature females on the assumption that ewes bear t h e i r f i r s t young at age three.  The number of two-year old ewes was  assumed to be equal to the number of two-year old males as determined i n section 6.2.3. The calculated lamb:ewe ratios which averaged 91:100 seem high, especially since some individually recognized ewes older than two years either did not bear young or lost them soon after b i r t h .  It i s  possible that the estimated number of two-year o l d ewes i s too high.  It is  Table 25 Percentage composition of the ewe-juvenile band at Nevis Mountain. The actual number counted i s shown i n brackets beside the percentage f o r each class.  Date  Lambs  Age and Sex Classes Ewes Yearlings  Rams I  Total  Summer/69  32(9)  46.5(13)  18(5)  3.5(1)  28  Summer/70 Mean summer count  29(12)  ~ST~"  44(18) 45  22(9) 20  5(2) 4  41  24.5(11)  51(23)  22(10)  2.5(1)  45  Winter/ 1969- 70 Winter 1 9 7 0 -7 1  Mean Winter count Mean Total  30(12) 7  50(20) 5 0 , 5  20(8) 2 1  0(0)  40  1  2  29(11)  48(19)  20.5(8)  2.5(1)  39  98  Table 26  Lamb:ewe ratios from early summer counts i n the Nevis Creek area.  Observed r a t i o  Calculated  Area  Date  Nevis Mountain  1969  76/100  95/100  Nevis Mountain  1970  70/100  87.6/100  *Richards CreekNevis Creek  1969  86/100  107.5/100  "Besa RiverNevis Creek  1970  63.5/100  79,5/100  74/100  91/100  Average  " Ratios from single counts with no duplication  ratio  99 also possible  that  ewe-juvenile groups were more readily seen and counted  than the smaller and less active groups without lambSj.or single ewes. This i s suggested f o r the Richards Creek-Nevis Creek count by the high observed yearling:ewe r a t i o (54:100). 6.2.5  Juvenile and adult mortality  The change i n lamb:ewe ratios and between yearling:ewe ratios through time provides a r e l a t i v e measure of juvenile mortality.  The number of  young sheep born at Nevis Mountain i n the spring of 1969 per hundred ewes i s shown through successive seasons to March, 1971 i n Table 27.  Table 27  Seasonal changes i n numbers per hundred ewes of young sheep born at Nevis Mountain i n 1969. Figures i n brackets represent percent change.  *Ratio f?  Year  Summer  Fall  Winter  Lamb:ewe  1969/70  76:100  69:100(-9)  47.5:100(-31)  Yearling:ewe  1970/71  46.5:100(-2) 43:100(-7.5) 41:100(-4.5)  e  ^° Change  Total  t a l  -40 -14% -54%  The results i n Table 27 show a high mortality rate i n the f i r s t year of l i f e with most of i t occurring early i n the f i r s t winter. Mortality decreased sharply a f t e r the f i r s t year of l i f e , t o t a l l i n g only 14 percent i n the period from May, 1970 to March, 1971. The c l a s s i f i c a t i o n of adult males into four age classes provides a measure of adult mortality and survivorship f o r t h i s segment of the  100  101 population.  Figure 19 represents a survivorship curve f o r stone rams i n  the northern Rocky Mountains.  I t was derived from data presented i n  section 6.2.3(a). Figure 19 graphically i l l u s t r a t e s the period of high juvenile mortality discussed e a r l i e r .  This i s followed by a period of low mortality  during adult l i f e to about 8 or 10 years after which a second period of high mortality occurs.  The apparent decline i n survivorship between age  Class I and age Class I I rams i s thought to represent mainly a low count i n the l a s t three age classes. This i s discussed further i n section 6.3. The expected survivorship curve, assuming representative counts f o r a l l age classes, i s also shown i n Figure 19.. 6.2.6  Mortality factors  Although l i t t l e direct information was obtained on causes of mortality, s u f f i c i e n t data and observations were obtained to discuss the topic generally under the following headings: (a) Competition for forage As i s true f o r most stone sheep habitat, domestic livestock were not present on the alpine sheep range at Nevis Mountain. Observations indicate that competition for forage between sheep and other wild ungulates i s minimal at Nevis Mountain and over most of the f o o t h i l l s area.  Although  moose were commonly seen above treeline i n the northern f o o t h i l l s , they were predominantly browsers, feeding mainly on shrubs a meter or more i n height.  Deer are present only i n limited numbers i n the f o o t h i l l s and t h i s  species was seldom seen above t r e e l i n e .  Caribou were abundant throughout  the area, however, and this species commonly used the alpine habitat. Rumen samples collected from two caribou i n January, 1969, were analyzed by the water displacement method to determine i f there was a significant overlap  102  i n the forage classes used by t h i s species and those used by sheep.  The  results indicated that cryptogams, which made up 32 and 66 percent of the two samples were more important i n the winter diet of the caribou.  Grasses  and sedges were also important, however, t o t a l l i n g 44 and 30.5 percent by volume of the two rumen samples. In spite of t h i s overlap, competition for forage between sheep and caribou i s believed to be minimal since observations consistently indicated that these species favour different parts of the alpine zone.  In winter, caribou were often seen pawing through  several inches of snow on high plateaus or cool northern or eastern exposures to feed while sheep grazed on adjacent snow-free southern and western exposures.  Elk were rare at Nevis Creek but t h i s species i s  l o c a l l y abundant i n the Prophet, Muskwa^Tuchodi and Gathto drainages to the north where they appear to have been increasing i n recent years.  In areas  where they are l o c a l l y abundant, elk were using the alpine habitat and they appeared to favour the warm southern and western exposures that sheep depend on for winter range. Intraspecific competition f o r forage during severe winter weather i s probably more important as a cause of mortality.  Four juvenile sheep were  found dead on the winter range during t h i s study.  Condition of the bone  marrow indicated that three of these were suffering from severe malnutrition at the time of death, (b) Disease and parasites A l l seven of the sheep, ranging i n age from 2^ to 9h years, which were autopsied during the study showed evidence of lungworm infection.  In a l l  cases, the tissue i n the region of the diaphragmatic lobe had a mottled appearance as a result of few to many fibrous lesions indicating long-standing infection (Bandy, pers. comm.). Microscopic examination of the necrotic  103 tissue revealed few to numerous lungworm (Protostrongylus sp.) adults and larvae i n the parenchymal tissue.  The parasite has been tentatively  i d e n t i f i e d as P. s t i l e s i (Adams, Department of Zoology, University of B r i t i s h Columbia, Vancouver, 1971). Certain species of land snails belonging to the genera H e l i c e l l a , Oreohelix, P u p i l l a , Vertigo, and V a l l o r i a are known to serve as intermediate hosts f o r Protostrongylus lungworms (Buechner, 1960). At Nevis Mountain, an unknown species of small land s n a i l was very abundant i n the ElymusAgropyron community which the sheep grazed almost to ground l e v e l . Five of the seven sheep autopsied and the remains of several others k i l l e d by hunters or found dead on the range showed symptoms of actinomycosis. The disease, commonly called lumpy jaw, i s produced as a result of infection by the bacterium Actinomyces (Cowan, 1951). The infected animals had enlarged jaw bones, usually attended by chronic infection of tooth sockets as evidenced by loose or missing teeth. In spite of heavy lungworm infestation and diseased jaws, a l l of the animals autopsied i n the f i e l d had good f a t reserves, few external parasites and otherwise appeared i n good health. Occasionally, during the study, sheep were observed i n poor condition. These animals usually had a severe cough suggesting heavy lungworm infestation.  Also, i t was noticed  that, during a severe chase, b i g , old rams could not keep up to younger animals and were the f i r s t to show signs of respiratory distress.  This may  be due to lungworm infestation which would reduce the resilience and hence the t i d a l volume of the lungs as suggested by Geist (1971).  However,  these observations were made during mid-winter when the old rams were probably i n a r e l a t i v e l y more weakened condition from the r u t . On the whole, few sheep seen during t h i s study were unhealthy or i n poor condition.  104 (c) Injury During the study, several sheep were seen with leg injuries serious enough t o cause a limp and impede the animals movement. Such injuries may be due to a f a l l .  Although sheep which lose t h e i r footing when climbing  are usually able t o avoid a f a l l by jumping t o safer footing, t h i s i s not always the case.  On July 31, 1970, a young lamb at Nevis Creek slipped and  f e l l approximately 30 feet onto a rocky streambed.  In t h i s instance, the  animal landed on i t s feet and, though shaken momentarily, i t did not appear to suffer serious injury. panicked.  The sheep are more susceptible t o injury when  In one instance, a ram received a serious cut on i t s haunch when  i t struck a sharp rock while fleeing a low-flying a i r c r a f t . Undoubtedly some sheep die from accidental injuries either d i r e c t l y or i n d i r e c t l y because they are more susceptible to predation, but on the whole t h i s appears to be a minor cause of mortality. (d) Predation Of the several predators i n the area, the wolf (Canis lupus) i s the most significant predator of sheep. Wolves were common i n the northern f o o t h i l l s area during t h i s study and, according t o l o c a l residents, t h e i r numbers had increased i n recent years. Evidence of wolves was not uncommon i n the alpine, especially i n winter when wolves were seen i n close proximity to sheep on several occasions. However, caribou and moose were also present on the alpine ranges and these appeared to be the most important prey species of the wolf as a number of k i l l s were sighted during the study period. No sheep k i l l s were observed though the stomach of a wolf shot by hunters i n early August contained the remains of a lamb. I t seems worth noting that a l l of the wolf dens observed during t h i s study were at low elevation, adjacent to beaver ponds or t o mineral l i c k s  105  frequented by moose and caribou. Although evidence i s lacking, i t seems doubtful that wolves were s i g n i f i c a n t l y influencing stone sheep populations i n the northern f o o t h i l l s during t h i s study. Both golden eagles (Aquila chrysaetas) and bald eagles (Haliaeetus leucocephalus) were present i n the study area. Although eagles were seen diving at young sheep on several occasions, i n a few cases quite persistently, no successful attack was witnessed.  The sheep were alerted by the nearby  presence of an eagle, p a r t i c u l a r l y when the lambs were very young. When an attack occurred, the ewe stood over or close t o the lamb and watched the eagle closely. strike i t .  In a few cases, ewes jumped at a diving eagle as i f t o  Although they even made dives at yearlings on occasion, low-  f l y i n g eagles frequently ignored the sheep altogether. Coyotes were present but not numerous and i n the only attack witnessed, a ewe and 3 months old lamb easily outdistanced the predator by running up a steep slope. Black bears, g r i z z l i e s , lynx and wolverine were also present i n the area but they too appeared unimportant as predators of sheep. In addition t o the sheep remains found i n the stomach of a wolf, scats of wolves, bears and wolverines were seen, which appeared t o contain sheep hair.  However, t h i s i s not necessarily evidence of a k i l l .  Two incidences  during t h i s study served t o show how quickly and e f f i c i e n t l y predators can locate the carcass of dead animals.  In one case, three black bears  appeared at the scene of a sheep k i l l within 48 hours, one within 10 hours, though none had been seen on the alpine sheep ranges for almost two months. In another, the carcass of a sheep shot during a snowstorm and covered with a clean canvass tarp and several inches of snow was located by wolves within a few days.  The wolves, which had been hunting i n the  106  valley when the sheep was shot, located the carcass i n the alpine during a period with l i t t l e wind and temperatures well below zero. (e) Hunting Hunting i s an important source of mortality, at least i n the older age class ram segment of the population. There i s a long history of guided hunting and, more recently, resident hunters have begun to exploit sheep populations i n the northern Rockies. Although guides and other l o c a l residents report that rams smaller than 3/4 c u r l (age class I I I ) and, occasionally, ewes and juvenile sheep are shot, guided trophy hunters have always selected the older, f u l l c u r l or larger rams* .  Recent  hunting  regulations have • been -^snacted—fee- r e s t r i c t the k i l l to this segment of the population.  In a guide's area near Nevis Creek, 142 rams, most of which  were f u l l c u r l or larger, were harvested by hunters i n the five-year period p r i o r to 1972 (Harper, pers. comm. 1972). The estimated mean age of the rams was 9.13 years, the youngest being 5^ years and the oldest 13h years of age (n = 78). 6.3  Discussion The movements and distribution of the sheep at Nevis Mountain were  dictated by t h e i r needs, by the physical limitations of their environment and by t r a d i t i o n .  In winter, unfavourable snow depths caused the sheep to  concentrate on exposed sunny and windswept slopes representing less than 20 percent of t h e i r t o t a l productive habitat. During c r i t i c a l periods i n the winter and again i n early spring, the sheep r e l i e d heavily on forage from the Elvmus-Agropyron community. This community, which has developed on calcareous s o i l s of warm southern exposures, occupies less than 20 percent of the winter range area.  In summer the sheep ranged widely, making f u l l  107 use of the varied habitats available to them. Mineral l i c k s , i n which sodium appears to be the attractive element, were v i s i t e d frequently from late spring to early f a l l .  Sodium i s considered the attractive element i n  the predominance of studies which have analyzed mineral l i c k s i n North America (Hebert, 1967).  The function and importance of mineral l i c k s i s  uncertain, though i t i s generally assumed that they supplement a dietary or physiological need (Cowan and Brink, 1949).  Whatever their importance  otherwise, t h e i r attraction i s strong and they have a major influence on the movement and distribution of sheep i n certain seasons.  They cause the  sheep to concentrate and to t r a v e l f a r from escape t e r r a i n where they are more susceptible to predation. Through them t r a d i t i o n a l routes are maintained, providing a l i n k between the home ranges of different bands of sheep. They may also be important as a source of transfer of disease or parasites (Green, 1949) or as s o c i a l centres (Knight and Mudge, 1967). According to the results of c l a s s i f i e d counts, stone sheep populations i n the f a l l averaged about 35 percent ewes and 27 percent rams 2\ years or older, 24 percent lambs and 14 percent yearlings. About three or four percent of the population, or twelve percent of the mature rams were 3/4 c u r l rams or larger and therefore l e g a l game under existing hunting regulations. Only three or four percent of these, or one or two percent of the t o t a l population were f u l l c u r l or larger rams which are so highly prized as trophy animals. As indicated i n section 6.2 the c l a s s i f i e d counts are subject t o several possible sources of error, of which duplication i s one.  This  source of error i s expected to be greater i n counts conducted on the ground, such as the summer counts at Nevis Creek, since groups of sheep are constantly moving and exchange constantly occurs between groups.  108  However, i t appears to be a minor source of error, since the averaged results of counts from Nevis Mountain are closely comparable with the averaged results of a l l counts combined. I t i s usually necessary to conduct counts over an extensive area t o get a representative sample of the population.  The sheep not only segregate sexually into ram-ewe groups,  but juveniles occasionally form groups and ewes without lambs tend t o separate from ewe-juvenile groups shortly after the lambing season.  While  time l i m i t s the size of area that can be covered on foot or horseback, a e r i a l counts are more subject to errors i n i d e n t i f i c a t i o n especially where fixed-wing a i r c r a f t are used.  The high variance i n age classes of rams and  between ram:ewe ratios i n the different counts indicates how d i f f i c u l t i t i s to obtain representative counts of the ram segment of the population. Rams tend t o occur i n smaller groups and t o favour different t e r r a i n as well as different areas than ewe-juvenile groups.  Unfortunately, i t was  not possible t o conduct counts during the rut when both sexes occur together.  The number of Class I rams i n Table 24 i s thought t o be too high  i n r e l a t i o n to the last three age classes.  According to Leopold's breeding  table (1933) f o r animals which f i r s t bear young at three years.and bear one young per year, 23 percent of the males w i l l be two years o l d . This compares closely with the average results i n Table 24 which shows 24.5 percent of the mature rams i n this age class.  However, Leopold's breeding  table i s based on the assumption that a l l individuals survive so the number i n natural population would be somewhat lower than 23 percent. The high proportion of Class I rams i s probably due t o a poor representation of rams i n the last three age classes.  This may be due t o a low count of  these animals as seems apparent i n the Stone Mountain-Sentinel Range count. However, i t i s also due partly t o hunting since most populations i n the  109 northern f o o t h i l l s are subject to trophy hunting which selects strongly for the largest horned and, therefore, usually the oldest animals. According to the results i n Table 24, there was an average of 80 mature rams per 100 mature ewes i n these populations. The oldest age Class IV, which comprised only 10 percent of the ram population, was the most poorly represented i n view of the large spread i n years which i t represents. I t i s generally thought that the sex r a t i o i n natural unhunted populations of mountain sheep i s about equal (Buechner, 1960 and Geist, 1971). Geist (1971) found a mature ram:ewe r a t i o of 88:100 at Gladys Lake i n the .Cassiars.  The adult ram population i n Geist's stone sheep study area  averaged 24 percent Class IV rams. Hunting pressure on the populations i n the northern Rockies i s thought to be greater than i t was on the populations studied by Geist i n the Cassiars i n 1961-62. As indicated i n Section 6.2.4 the calculated lamb:ewe ratios shown i n Table 26 seem high, p a r t i c u l a r l y since some ewes older than 2 years did not bear young.  I t i s possible that the observed ratios were too  high i n i t i a l l y because ewe-juvenile groups were more readily seen and counted than ewes without lambs. Although t h i s i s suggested i n the Richards Creek-Nevis Creek count by the high yearling:ewe r a t i o (54:100), i t i s not thought t o be so i n the other counts.  I t i s more probable that  the estimate of 20 percent 2-year old ewes used i n deriving the calculated ratios i s too high. However, i t i s possible that some two-year o l d ewes gave b i r t h or that some ewes bore twins.  Since two-year old ewes cannot  be recognized with any degree of certainty i n the f i e l d , there was no way of knowing i f any bore young. Apparently yearling sheep w i l l breed successfully under conditions of excellent n u t r i t i o n .  Woodgerd (1964 and  Buechner (1960) c i t e instances of successful breeding by yearling bighorn  110 ewes. Although twinning i s apparently uncommon i n natural sheep populations, Buechner (1960) cites several cases of twinning i n Rocky Mountain bighorn sheep. Spalding (1966) found that four out of eleven C a l i f o r n i a bighorn (Ovis canadensis californiana) k i l l e d on a road i n southern B r i t i s h Columbia were carrying twins. Although ewes with more than one lamb and groups with more lambs than ewes were seen on several occasions, no positive evidence  of twinning was obtained during this study i n the northern  Rockies. Estimates of mortality f o r juvenile sheep were derived from r e l a t i v e changes through time i n the numbers of a single cohort group and i s subject to fewer sources of error than estimates derived from differences i n numners of different age class animals.  These estimates are expected to be  low i f anything, since they are based on the assumption of no mortality of adult ewes. Although no estimate of mortality i s available f o r adult ewes i n this population, i t i s expected that some took place over the two year period. Geist (1971) estimated an average mortality rate of about 11.7 percent and 20 percent respectively f o r adult ewes i n bighorn populations studied by Hansen (1967) and Wishart (1958). Interspecific competition f o r forage appeared to be minimal at Nevis Creek, but i t may occur with elk on c r i t i c a l sheep winter range i n other parts of the northern f o o t h i l l s .  Although elk are commonly browsers,  Cowan (19173) found the food habits of elk i n the National Parks cut right across those of other ungulate species present, including sheep. On the Nevis Creek sheep range, i n t r a s p e c i f i c competition during periods of deep snow or severe i c i n g conditions probably contributes more s i g n i f i c a n t l y to mortality.  Lungworm and actinomycosis appear to be common diseases of  stone sheep i n the study area.  Lungworms are frequently the cause of  Ill d e b i l i t y and death i n mountain sheep either d i r e c t l y or by weakening the host so that i t i s susceptible to accidental predation, malnutrition or disease of the septicemic or actinomycotic groups (Cowan, 1944). Actinomycosis contributes to mortality through malnutrition because of i t s effect on jawbones and teeth. Cowan (1940) refers t o stone sheep shot i n early autumn which were i n poor and weakened condition apparently as the direct result of the loss of t h e i r teeth. He suggests that the maximum age i n sheep i s limited largely by the l i f e span of t h e i r teeth. Certainly the teeth of some of the diseased sheep at Nevis Creek were i n very poor condition.  There are references t o actinomycosis i n stone sheep populations  from some very early records ( B l a i r , 1907 and House, 1909). According t o Cowan (pers. comm.), t h i s disease, now uncommon i n B r i t i s h Columbia bighorn populations, was very common i n the sheep at Banff when he studied populations there i n the 1940's. Wolves appear t o be the most serious predator of sheep i n the northern f o o t h i l l s but casual observations suggest that they are probably not an important l i m i t i n g factor on these populations.  During h i s studies i n  Jasper National Park, Cowan (1947b) found that wolves not only f a i l e d to remove the net increment of,their ungulate prey populations, they f a i l e d even t o remove the diseased and injured animals.  However, d a l l sheep  populations studied by Murie (1944) were depressed by wolf predation i n a complex situation dependent on concurrent changes i n wolf and sheep populations. A decline i n sheep numbers due to severe snow conditions and a corresponding increase i n wolf numbers led t o the situation where wolves were able to cause a decrease i n the surviving population, mainly by preying on the o l d , the diseased, and the lambs during the f i r s t winter.  Pimlot (1967) suggests that the interaction of the variables of  112  predation and the different environmental variables encountered produce such complexities that few generalizations are possible on the influence of predation by wolves on prey populations.  Eagles did not appear to be a  significant predator on young sheep i n the study area.  Although there are  several records of successful predation on native sheep by eagles, no studies suggest that such predation has an important l i m i t i n g effect on the population'.  1 1 3  7. GENE PAL DISCUSSION AND CONCLUSIONS  Diversity characterizes the Nevis Creek study area.  Physiographic,  climatic and edaphic diversity i s reflected by the vegetation which presents a complex, heterogeneous pattern l o c a l l y t o a degree seldom observed i n more southern latitudes.  This complex pattern appears t o be duplicated r e p e t i t i v e l y  throughout the northern f o o t h i l l s , however, so the data presented here should have a regional as well as a l o c a l a p p l i c a b i l i t y . Climate, l i k e most other variables, i s strongly influenced by topography. The important contribution of l o c a l climate t o vegetative d i v e r s i t y i s v i s i b l y apparent i n s t r i k i n g f l o r i s t i c differences on different slopes and exposures. Thus the contrast between the productive Elymus-Agropyron community on steep southern exposures and the r e l a t i v e l y unproductive, l i k e cryptogam - Salix community on d i r e c t l y opposing slopes.  tundra-  Exposed alpine  ridges from treeline t o summit elevations support plant communities characterized by a sparse cover of low-growing forbs, grasses and sedges which have a high degree of tolerance t o dessication, wind breakage and low s o i l temperatures. In contrast, shrubs and even low-growing trees have established f a r above treeline i n protected places where accumulated snow provides a blanket of protection. Soils have contributed notably t o f l o r i s t i c d i v e r s i t y i n the alpine zone where they have developed i n highly s t r a t i f i e d contrasting bedrock formations disturbed l i t t l e by glaciation.  Dystric Brunisols, Gleysols and  Regosols developed i n acidic parent materials prevail.  Although these s o i l s  support a range of plant communities, they are limited by associated low temperatures, extreme a c i d i t y and saturated conditions, and the plant  114  communities t h e y s u p p o r t r e f l e c t t h i s b o t h f l o r i s t i c a l l y and by low p r o d u c t ivity.  E u t r i c B r u n i s o l s and Chernozem-like  o f s o u t h e r n exposures  s o i l s on b a s i c g e o l o g i c m a t e r i a l s  s u p p o r t p r o d u c t i v e g r a s s l a n d communities which y i e l d  high quality forage. S t a b i l i t y i s a l s o c h a r a c t e r i s t i c o f the v e g e t a t i o n i n the study area. Even t h e w i d e s p r e a d  s e r e s below t r e e l i n e a r e c h a r a c t e r i z e d by slow r a t e s o f  s u c c e s s i o n w h i l e t h e a l p i n e p l a n t communities,  largely free of a  h i s t o r y , a r e e x t r e m e l y s t a b l e c l i m a x o r d i s c l i m a x communities.  fire Trends  i n d i c a t i n g l o n g - t e r m changes a r e a p p a r e n t , however, and a r e s i g n i f i c a n t because  t h e y a r e i n c l i n e d t o reduce t h e a v a i l a b l e h a b i t a t f o r sheep.  t h e slow, c u m u l a t i v e s p r e a d o f shrubs onto g r a s s l a n d s i s due, s e l f - i n d u c e d m i c r o c l i m a t i c changes,  here  Although  i n part, to  t h e w i d e s p r e a d and p e r s i s t e n t n a t u r e o f  t h i s t r e n d and o f t h e p o l u d i f i c a t i o n o f a l p i n e communities on c o o l  exposures  by mosses and l i c h e n s s u g g e s t s a r e s p o n s e t o more g e n e r a l c l i m a t i c  changes.  Such t r e n d s may  be due t o l o n g - t e r m  c l i m a t i c changes.  North P a c i f i c  North  A m e r i c a has undergone t h r e e major c l i m a t i c i n t e r v a l s s i n c e t h e P l e i s t o c e n e p e r i o d o f g l a c i a t i o n , t h e t h i r d and p r e s e n t o f which has been marked by c o o l i n g and r i s i n g h u m i d i t y may  (Heusser, 1960).  On t h e o t h e r hand, t h e s e t r e n d s  be due t o r e l a t i v e l y s h o r t - t e r m c l i m a t i c s h i f t s .  Climatologists  now  r e c o g n i z e t h a t r e l a t i v e l y s h o r t - t e r m c l i m a t i c s h i f t s s u f f i c i e n t t o have i n f l u e n c e d e c o l o g i c a l e v e n t s have o c c u r r e d w i t h i n t h e p a s t c e n t u r y and  that  f o r many c o u n t r i e s t h i s s h i f t has been p a r t i c u l a r l y s i g n i f i c a n t i n t h e  last  decade (Lamb, 1969).  Recent  c l i m a t i c s h i f t s have been suggested as an  e x p l a n a t i o n f o r t h e advance o f aspen f o r e s t o n t o g r a s s l a n d s i n n o r t h e r n and c e n t r a l B r i t i s h Columbia  ( B r i n k and F a r s t a d , 1949)  and f o r t h e advance o f  s u b a l p i n e f o r e s t onto a l p i n e h e a t h i n t h e G a r i b a l d i a r e a ( B r i n k , L i g h t g l a c i a t i o n i n t h i s a r e a suggests the p o s s i b i l i t y t h a t  1959). refugia  115  may have existed i n the Northern f o o t h i l l s during one or more of the Pleistocene periods.  This, i n turn, suggests a possible explanation f o r  the o r i g i n and d i s t r i b u t i o n of stone sheep. So f a r there has been no satisfactory explanation f o r the o r i g i n and distribution of stonei which d i f f e r s s i g n i f i c a n t l y from d a l l i t o have required at least a period of separation of the o r i g i n a l stocks (Cowan, pers. comm., 1970). The view that plant and animal species have been able t o survive throughout long g l a c i a l periods i n r e s t r i c t e d ice-free areas or closed refugia i s supported by recent evidence from Alaska and Iceland (Lindroth, 1970). Diversity and s t a b i l i t y appear t o be important environmental features of stone sheep habitat i n the Nevis Creek study area.  The juxtaposition of  diverse habitats largely enables the sheep t o meet t h e i r needs i n an often harsh alpine environment of limited extent.  In keeping with t h e i r more stable  environment where changes are due mainly t o long-term events, sheep populations i n t h i s area appear t o fluctuate less v i o l e n t l y than bighorn populations further south. Many bighorn populations i n North America have suffered serious d i e offs which have been linked t o a lungworm-pneumonia disease complex i n which heavy lungworm infestation i s considered t o be a predisposing agent f o r pneumonia (Buechner, 1960).  Buechner has suggested that many bighorn popul-  ations are controlled by such die-offs but a number of attendant environmental factors preceding  the disease complex may actually be the causal agent.  Recent bighorn die-offs i n southern B r i t i s h Columbia affected populations dependent on low elevation grasslands f o r winter habitat. The grasslands, expanded by widespread f i r e s i n the past, were shrinking due t o forest succession.  Overgrazing by domestic livestock and by game and severe winter  conditions coincident with shrinking winter ranges i s believes t o have  116  lowered the animals' resistance and triggered the die-off (Bandy, 1968). Stelfox (1971) reports that bighorn sheep populations i n the Canadian Rockies were d r a s t i c a l l y reduced between 1937 and 1949 by a series of die-offs which were attributed to lungworm-pneumonia disease, deteriorated ranges, heavy elk and livestock competition, shrinking winter ranges due to forest succession and three severe winters between 1946 and 1949.  Although l o c a l  residents reported heavy losses i n stone sheep populations during severe winters with deep snow, there have been no reports which suggest a major dieoff such as occur i n bighorn populations.  I t appears that enzootic die-offs  are not a feature of the sheep populations i n t h i s r e l a t i v e l y p r i s t i n e , , stable environment even though the necessary disease organisms are present. The sheep at Nevis Creek were mainly dependent on herbaceous vegetation from the r e l a t i v e l y stable alpine communities f o r t h e i r protein and carbohydrate requirements.  Serai grasslands tend to be short-lived and largely  unsuitable f o r wintering sheep as they are rapidly invaded by shrubs which reduce the herbaceous ground cover and cause d r i f t i n g snow to accumulate. The fortuitous combination of several environmental variables provided c r i t i c a l winter range on exposed south and west facing slopes. Here, Chernozem-like s o i l s and Eutric Brunisols having the favourable s o i l chara c t e r i s t i c s of moderately coarse texture, moderate s o i l reaction, good drainage and an adequate nutrient status have combined with a favourable microclimate to support the most productive and nutritious alpine forage. Furthermore, the forage i s largely available f o r wintering sheep because of reduced snow depths, and though forage productivity i s t y p i c a l l y low compared with lower altitudes, quality i s high and i s maintained i n the cured stage by sharp f a l l frosts and the persistent winter cold. Although t h e i r habitat includes a broad spectrum of necessary elements,  117 a l l of which are important, the Elymus-Agropyron.community i s p a r t i c u l a r l y significant.  This plant community, which occupied less than twenty percent  of the winter range and four percent of the t o t a l productive habitat, provided almost sixty percent of the forage f o r wintering sheep. Competition f o r forage was minimal i n the r e l a t i v e l y undisturbed sheep habitat at Nevis Creek, but i t may occur with elk on c r i t i c a l sheep winter ranges i n other parts of the northern f o o t h i l l s .  In these areas, elk  populations appear to be expanding i n the wake of repeated f i r e s .  Fire has  produced short-term benefits for several ungulate species, including sheep^ i n the northern f o o t h i l l s area.  However, maintenance of serai vegetation by  repeated burning should be approached with caution and s i t e - s p e c i f i c information.  The long-term effects on the habitat, the chance of producing  unfavourable seres and the d i f f e r e n t i a l effects on a l l species should be considered.  Fire has been shown to reduce the quality and quantity of  habitat f o r caribou for long periods of time (Scotter, 1964), and has been correlated with population declines of this species throughout most of B r i t i s h Columbia (Edwards, 1954). The alpine habitat of stone sheep, largely protected by i s o l a t i o n i n the past, i s rapidly becoming exposed to the influence of man with accelerated development of the north. As low productivity rates and slow succession rates emphasize, alpine ecosystems are sensitive and slow to recover from abuse, factors that should be considered prior to any interference by man.  Major  changes to or destruction of t h e i r habitat could seriously reduce stone sheep populations dependent on i t , possibly by triggering enzootic die-offs due to lungworm-pneumonia disease complex as i n bighorn populations of more southern latitudes.  8. LITERATURE CITED  Association of O f f i c i a l Agricultural Chemists. 1960. O f f i c i a l methods of analysis. 10th edition. (Washington, D.C.) Bandy, P.J. 1968. Rocky Mountain bighorn sheep losses i n the east Kootenay region of B.C. 1965-1967. A paper presented t o the Northwest Section, the W i l d l i f e Soc. Univ. of A l t a . Edmonton (Mar.23). B l a i r , W.R. 1907. Actinomycosis i n the black mountain sheep. N.Y. Zool. Soc. Ann. Rept. 11:132 pp. Bowden, G. and P.H. Pearse. 1968. Nonresident big game hunting and the guiding industry i n B r i t i s h Columbia; an economic study. Dept. of Recreation and Conservation (Victoria). 72pp. Brink, V.C. and L. Farstad. 1949. Forest advance i n north and central B r i t i s h Columbia. The Can. F i e l d Naturalist. Jan-Feb. Brink, V.C. 1959. A directional change i n the subalpine forest - heath ecotone i n Garibaldi Park, B r i t i s h Columbia. Ecology, V.40 No. 1 pp. 10-15. Brink, V.C, A. Luckhurst and D. Morrison. 1972. Productivity estimates from alpine tundra i n B r i t i s h Columbia. Can.J.PI.Sci. V.52, No. 3 (Ottawa). Brown, Dorothy. 1954. Methods of surveying and measuring vegetation. Commonwealth Agric. Bureaux Farnham Royal, Bucks., England. 223 pp. Buechner, H.K. 1960. The bighorn sheep i n the United States, i t s past, present and future. Wildl. Monogr. 4:1-174. Canada Department of Agriculture. 1970. The system of s o i l c l a s s i f i c a t i o n f o r Canada (Ottawa). Canada Department of Transport, Meteorological Branch. 1965. Temperature normals f o r B r i t i s h Columbia. Climatic data sheet No. 3-65 (Toronto). 1967. Temperature and precipitation tables f o r B r i t i s h Columbia. (Toronto). 1968a. Climatic Normals Vol. 5. Wind (Toronto). 1968b. Climatic Normals. Vol. 6. Frost data (Toronto). 1970.  Monthly records (Toronto).  Chamrad, A.D. and T.W. Box. 1964. A point-frame f o r sampling rumen contents. J.Wildl. Mgmt. 28(3): 473-477.  119  Chapman, J.D. 1952. The climate of B r i t i s h Columbia. Paper presented at 5th B r i t i s h Columbia Nat. Res. Conf. Univ. of B r i t i s h Columbia (Feb. 27). Cowan, I.MoT. 1940. Distribution and variation i n the native sheep of North America. Am. Midi. Nat. 24(3): 505-580. 1944. Report of w i l d l i f e studies i n Jasper, Banff and Yoho National Parks and parasites diseases and injuries of game animals i n the Rocky Mountain National Parks of Canada. Wildl. Serv. Ottawa. 83pp. (mimeo). 1947. Range competition between mule deer, bighorn sheep and elk i n Jasper Park, Alberta. Trans. N. Am. Wildl. Conf. 12:223-227. 1947b. The timber wolf i n the Rocky Mountain National Parks of Canada. Can.J. Res. 25: 139-174. , and V.C. Brink. 1949. Natural game l i c k s i n the Rocky Mountain National Parks of Canada. J . of Mammal. 30(4): 379-387. , and C.J. Guiget. 1965. The mammals of B r i t i s h Columbia. Prov. Mus. Hndbk. No. 11 (Victoria). 1951. The diseases and parasites of b i g game mammals of western Canada. Proc. Ann. Game Cons. B.C. Game Dept. 5:37-64. Daubenmire, R.F. 1968. Plant communities, a textbook of plant synecology. Harper and Row Publ. N.Y. 300 pp. Daubenmire, R.F. 1959. A canopy coverage method of vegetational analysis. Northwest S c i . 33(1): 43-64. Demarchi, D.A. 1970. Effects of grazing on the botanical and chemical composition of range vegetation i n the lower Chilcotin River region, B r i t i s h Columbia, M.Sc. thesis, Library, Univ. of Idaho. Demarchi, R.A. 1968. Chemical composition of bighorn winter forages. J . Range Mgmt. 21(6):385-588. Dirschl, H.J. 1963. Food habits of the pronghorn i n Saskatchewan. J . W i l d l . Mgmt. 27(1): 81-93. Edwards, R.Y. 1954. Fire and the decline of a mountain caribou herd. J . Wildl. Mgmt. 18: 521-526. Geist, V. 1968. On the interrelation of external appearance, s o c i a l behaviour and social structure of mountain sheep. Zs. Tierpsychol. 25: 199-215. 1971. Mountain sheep. A study i n behaviour and evolution. Univ. of Chicago Press. 383 pp.  120  Green, H.U. 1949. The bighorn sheep of Banff National Park. Natnl. Parks Hist. Sites Serv. Dev. Serv. branch (Ottawa). 53pp. Godfrey, W.E. 1966. The birds of Canada. National mus. of Can. B u l l . Series No. 73. 428pp. Hansen, G. 1967. Bighorn sheep populations of the Desert Game Range. J . W i l d l . Mgmt. 31: 693-706. Harper, F.E. 1969. Effects of certain climatic factors on the productivity and a v a i l a b i l i t y of forages on the Ashnola bighorn winter ranges. M.Sc. thesis, Library, U.B.C. Harper, F.E. 1972. Personal communication. Regional W i l d l i f e B i o l o g i s t , B.C. Fish and W i l d l i f e Branch, Fort St. John, B.C. Hebert, D.M. 1967. Natural s a l t l i c k s as a part of the ecology of the mountain goat. M.Sc. thesis, Library, U.B.C. Heusser, C.J. 1960. Late Pleistocene environments of north P a c i f i c North America. Am. Geog. Soc. Spec. Publ. No. 35. Hitchcock, C.L., A. Cronquist, M. Ownbey and D.W. Thompson. 1955, 1959, 1961, 1964, 1969. Vascular plants of the p a c i f i c northwest. Univ. of Wash. Publ. i n Biology. 5 vols. Univ . of Wash. Press (Seattle). Holland, S.S. 1964. . Landforms of B r i t i s h Columbia, a physiographic outline. B u l l . 48, B.C. Dept. Mines and Natural Resources (Victoria). House, E.J. 1909. A hunters campfires. Harper and Bros. pub. N.Y. and London. Hubbard, W.A. 1955. The grasses of B r i t i s h Columbia. Prov. Mus. Hndbk. No..9 (Victoria). Hulten, E. 1968. Flora of Alaska and neighbouring t e r r i t o r i e s . Stanford Univ. Press (Calif.) Johnson, A., L.M. Bezeau and S. Smoliak. 1968. Chemical composition and i n v i t r o d i g e s t i b i l i t y of Alpine tundra plants. J . Wildl. Mgmt. 32(4): 773-777. Knight, R.R. and M.R. Mudge. 1967. Characteristics of some natural l i c k s i n the Sun River area, Montana. J . Wildl. Mgmt. 31(2):293-299. Leopold, A. 1933. Game Management. Charles Scribners Sons, N.Y. Lindroth, CH. 1970. Survival of animals and plants on ice-free refugia during the Pleistocine glaciations. Lord, T.M. and A. McLean. 1969. A e r i a l photo interpretation on B r i t i s h Columbia rangelands. J . Range Mgmt. 22(1): 3-9.  121 Lord, T.M. 1972. Personal communication. Pedologist, Canada Agriculture, Vancouver, B.C. Mathews, W.H. 1971. Personal communication. Professor, Department of Geology, University of B r i t i s h Columbia (Vancouver). McLearn, F.H. and E.D. Kindle. 1951. Geology of north-eastern B r i t i s h Columbia. Geol. Surb. Canada Mem. 259 (Ottawa). Moss, E.H. 1959. Flora of Alberta. Univ. of Toronto Press. (Toronto). Murie, A. 1944. The wolves of Mount McKinley Fauna Series No. 5 (Washington). National Research Council, U.S.A. 1964. Committee on animal nutrition. Nutrient requirements of domestic animals. No. 5, Nutrient requirements of sheep. (Washington). National S o i l Survey Committee of Canada. 1968. Proceedings of the seventh meeting held at Edmonton, Alberta (Ottawa). P e l l e t i e r , B.R. and D.F. Stott. 1963. Trutch map-area, B r i t i s h Columbia. Geol. Surv. Canada, Paper 63-10. (Ottawa). P e l l e t i e r , B.R. 1964. Triassic stratigraphy of the Rocky Mountain f o o t h i l l s between Peace and Muskwa Rivers, northeastern B r i t i s h Columbia. Dept. of Mines and Tech. Surveys (Ottawa). Pimlott, D.H. 1967. Wolf predation and ungulate populations. Amer. Zoologist 7: 267-268. Poulton, C E . and E.S. Tisdale. 1961. A quantitative-method f o r the description and c l a s s i f i c a t i o n of range vegetation. J . Range Mgmt. 14(1): 13-21. Rowe, J.S. 1959. Forest regions of Canada B u l l 123. Can. Dept. Northern A f f a i r s and Natural Resources (Ottawa). Schofield, W.B. 1969. Some common mosses of B r i t i s h Columbia. Prov. Mus. Hndbk. No. 28 (Victoria). Scotter, G.W. 1964. Effects of forest f i r e s on the winter range of barren ground caribou i n northern Saskatchewan. Can.. Wildl. Serv. Wildl. Mgmt. B u l l . Series 1, No. 18 (Ottawa). Spalding, D.J. 1966. Twinning i n bighorn sheep. J . Wildl. Mgmt. 30: 207-208. Stelfox, J.C. 1971. Bighorn sheep i n the Canadian Rockies. A History 18001970. The Can. Field Naturalist 85(2): 101-122. Vince, G, 1970. Personal communication. Hunting guide and o u t f i t t e r , Fort. St. John, BC. Willard, B.E. and Marr, J.W. 1971. Recovery of alpine tundra under protection a f t e r damage by human a c t i v i t i e s i n the Rocky Mountains of Colorado.  122  B i o l . Conserv. 3: 181-190. Wishart, W.D. 1958. The bighorn sheep of the Bighorn Sheep River Valley. M.Sc. thesis. Library, Univ. of Alberta (Edmonton). Wang, J.Y. 1963. Agricultural meteorology. Pacemaker Press, LaCross, Wise. 693pp.  APPENDIX 1  S c i e n t i f i c and ccmmon names and authorities f o r plant species i d e n t i f i e d i n the Nevis Creek area. References include: Hitchcock et a l (1955, 1959, 1961, 1964,1969), Hubbard (1969), Hulten (1968), Moss (1959) and Schofield (1969).  Specimens are available at the University of B r i t i s h Columbia herbarium f o r a l l species with a c o l l e c t i o n  number.  124  S c i e n t i f i c and common names and authorities for plant species identified i n the Nevis Creek study area. Grasses and sedges: G52  Agropyron subsecundum Link Hitchc.  bearded wheatgrass  G53  Agropyron violaceum (Hornem.) Lange  wheatgrass  Ggb22  Arctagrostis l a t i f o l i a (R.Br.) Griseb.  polar grass  G7  Bromus Pumpellianus Scribn.  brome grass  G9  Calamagrostis lapponica (Wahlenb.) Hartm.  reed-bent grass  GS  Carex atrata L.  sedge  G51  Carex limosa L.  sedge  G50  Carex pennsylvanica Lam.  sedge  Ggb20  Deschampsia caespitosa (L.) Beauv.  tufted hairgrass  GI  Elymus innovatus Beal  hairy wild-rye  G5  Festuca ovina L.  sheep fescue  G4  Festuca scabrella Torr.  rough fescue  G6  Hierochloe alpina (Sw.) Roem and Schult.  alpine holy grass  Gil  Kobresia myosuroides ( V i l l . ) F i o r i S Paol.  kobresia  G15  Phleum commutatum Gandoyer  mountain timothy  G54  Poa alpina L.  alpine bluegrass  G3  Poa arctica R.Br.  a r c t i c bluegrass  Ggb25  Poa fendleriana (Steud.)Vasey  Fendler's bluegrass  G10  Poa leptocoma t r i n .  loose-flowered bluegrass  Ggb24  Poa nevadensis Vasey  Nevada bluegrass  G3  Poa rupicola Nash.  timberline bluegrass  G55  Poa  bluegrass  G2  Trisetum spicatum (L.) Richter  sp.  spike trisetum  125 Forbs: F56  A c h i l l e a millefolium L. subsp. borealis Bong.  yarrow  F45  Aconitum delphinifolium DC.  monkshood  Fgb5  Agoseris glauca (Pursh) Rof.  f a l s e dandelion  F228  Anemone multifida Poir.  cut-leaved anemone  F6  Anemone n a r c i s s i f l o r a L.  anemone  F15  Anemone p a r v i f l o r a Michx.  p r a i r i e windflower  F35  Antennaria monocephala DC.  white pussytoe  F59  Antennaria rosea Greene  rosy pussytoe  F36  Arnica alpina (L.) O l i n  alpine arnica  F61  Arnica c o r d i f o l i a Hook.  heartleaf arnica  F42  Artemisia norvegica Fries  Norwegian sage  Fgb208 Artemisia T i l e s i i Ledeb.  Tile's sage  Fgb204 Astragalus alpinus L.  alpine milk vetch  F50  Campanula lasiocarpa Cham.  bellflower  F43  Campanula u n i f l o r a L.  alpine harebell  Fgb205 Cardamine pratensis L.  cuckoo flower  F22  C a s t i l l e j a miniata Dougl.  common red-paintbrush  F33  Cerastium L. sp.  chickweed  F51  Cerastium L. sp.  chickweed  F222  Cornus canadensis L.  bunchberry  Fgb3  Crepis elegans Hook.  hawksbeard  F225  Crepis nana Richards  hawksbeard  Cryptantha interrupta (Piper) Payson F71  Delphinium br achy centrum Ledeb.  larkspur  F211  Draba aurea Vahl  golden whitlow grass  F221  Draba lanceolata Royle  draba  F23  Draba oligosperma Hook.  few-seeded draba  126 F217  Draba L. sp.  draba  Fll  Dryas i n t e g r i f o l i a M. Vahl  white dryas  Fgb7  Epilobium l a t i f o l i u m L.  large flowered fireweed  F49  Epilobium angustifolium L.  Fgb7  Erigeron acris L.  f leabane  F2  Erigeron grandflorus Rydb.  fleabane  F39  Erigeron hymilis Graham  fleabane  F63S64  Erigeron peregrinus (Pursh) Green  mountain daisy  common fireweed  subsp. callianthemus (Green ) Cronf. Fgb206 Equisetum arvense L.  common horsetail  F71(M) Equisetum scirpoides Mich.  dwarf h o r s e t a i l  F4  Fragaria virginiana Duchesne  wild strawberry  F54  Galium boreale L.  northern bedstraw  F38  Gentiana glauca P a l l .  gentian  F69  Gentiana propinqua Richards.  four-parted gentian  F5  Gentiana prostrata Haenke  white-margined gentian  Fgb6  Geum aleppicum Jaeq .  avens  F5  Hedysarum alpinum L.  lcments  subs, americanum (Michx.) Fedtsch Lathyrus ochroleucus Hook.  yellow-flowered peavine  Linnaea borealis L.  twin-flower  F16  Lupinus arcticus S. Wats.  a r c t i c lupine  F75  Luzula p a r v i f l o r a (Ehrh.) Desv.  wood rush  F47  Luzula spicata  spike wood rush  F67  Melandrium affine J . Vahl  4 o'clock  F44  Mertensia paniculata (Ait.) G. Don  t a l l mertensia  F29  Myosotis alpestris F.W. Schmidt  alpine  Fgb2  Oxyria digyna (L.) H i l l  mountain s o r r e l  F21  (L.) DC  forget-me-not  127 F227  Oxytropis deflexa (Pall.) DC.  deflexed locoweed  F18  Oxytropis nigrescens (Pall.) Fisch.  dark hair locoweed  F8  Oxytropis sericea Nutt.  early yellow locoweed  F100  Oxytropis splendens Dougl.  showy locoweed  F99  Parnassia palustris L.  bog star  Fgb207 Pedicularis Kanei E. Durand  hairy lousewort  F223  Pedicularis labradorica Wirsing  Labrador lousewort  Fl  Pedicularis oederi M. Vahl  lousewort  F25  Pedicularis sudetica W i l l d .  lousewort  F20  Penstemon procerus Dougl.  scorched penstemon  FIO  Polemonium actutiflorum Willd.  Jacobs ladder  F27  Polemonium pulcherrimum Hook.  Jacobs ladder  F41  Polygonum vivparum L.  alpine b i s t o r t  F26  P o t e n t i l l a d i v e r s i f o l i a Lehm.  mountain meadow cinquefoil  F7a  P o t e n t i l l a hookeriana Lehm.  cinquefoil  F7b  P o t e n t i l l a hyparctica Malte  cinquefoil  F3  P o t e n t i l l a nivea L.  cinquefoil  F226  P o t e n t i l l a pennsylvanica L.  Pennsylvanian cinquefoil  F7c  Potentilla villosa P a l l .  wolly cinquefoil  F202  Pyrola a s a r i f o l i a Michx.  common pink wintergreen  F55  Pyrola minor L.  lesser wintergreen  F37  Pyrola secunda L.  one-sided wintergreen  Fgb220 Ranunculus hyperboreus Rottb.  buttercup  F216  Ranunculus n i v a l i s L.  snow buttercup  F66  Rhinanthus minor L.  yellow r a t t l e  F40  Rumex acetosa L.  garden sorrel  F31  Saxifraga caespitosa L.  tufted saxifrage  128 F>48  Saxifraga cernua L.  tufted saxifrage  F24  Saxifraga f l a g e l l a r i s Willd.  spiderplant  F34  Saxifraga n i v a l i s L.  snow saxifrage  F30  Saxifraga oppositifolia  F229  Saxifraga punctata L.  cordate-leaved saxifrage  F9  Saxifraga tricuspidata Rottb.  prickly saxifrage  F53  Sedum lanceolatum Torr.  stonecrop  FM-6  Senecio lugens Richards.  ragwort  Fgbl  Senecio pauciflorus Pursch  ragwort  Sibbaldia procumbens L.  sibbaldia  L.  purple mountain saxifrage  F60S65 Silene acaulis L.  moss campion  F260  Silene parryi (Wats.) Hitchc. S Maguire  Parry's campion  F52  Silene repens Patrin  creeping campion  F 2 2 L |  Smilacina s t e l l a t a (L.) Desf.  star-flowered  F19  Solidago multradiata A i t .  goldenrod  F70  S t e l l a r i a longipes Goldie  long-stalked chickweed  F 32  Taraxacum alaskanum Rydb.  Alaska dandelion  Fgb4  Thlaspi arvense L.  pennycress  Thalictrum occidentale Gray  western meadow rue  Veronica wormskjoldii Roem £ Schult.  speedwell  V i i a americana Muhl.  American vetch  Zygadenus elegans Pursh  white camas  F62  G  F57  solomons-seal  Shrubs and half-shrubs:  S54  Alnus incana (L.) Moench  alder  Amelanchier a l n i f o l i a (Nutt.) Nutt.  Saskatoon  S23(M) Arctostaphylos rubra S5  (Rehd. S Wilson) Fern.  Arctostaphylos uva-ursi (L.) Spreng.  alpine bearberry bearberry  129 S17  Betula glandulosa Michx.  Cl  Cassiope tetragona (L.) D.  S26  Finpetrum nigrum L.  crowberry  Juniperus communis L.  common juniper  Ledum groenlandicum Oeder  Labrador tea  Lonicera involucrata (Richards.) Banks  black twinberry  S10  P o t e n t i l l a fruticosa L .  shrubby c i n q u e f o i l  S3  Rhododendron lapponicum (L.) Wahlenb.  Lapland rosebay  S53  Ribes oxyaconthoides L .  wild gooseberry  S12  Rosa a c i c u l a r i s L i n d l .  prickly, rose  S54  glandular b i r c h Don  white mountain heather  Fgb218 Rubus arcticus L .  t r a i l i n g raspberry  F72(N) Rubus chamaemorus L .  cloudberry  F219  Rubus idaeus L .  raspberry  S50  Salix alaxensis (Anderss.) Cov.  Alaska willow  S20  Salix b a r c l a y i Anderss.  Barclay's willow  S13  Salix glauca L .  glaucous willow  S23(N) Salix lanata L .  hairy willow  S51  Salix m y r t i l l i f o l i a Anders.  willow  S6  Salix polaris Wahlenb.  dwarf willow  Sl  Salix r e t i c u l a t a L .  netted willow  S21(b) Salix scouleriana Barratt  Scouler's willow  S21(d) Salix subcoerulea Piper  silvery-green willow  Shepherdia canadensis (L.) Nutt.  Soapalallie  S8  Vaccinium uliginosum L .  alpine blueberry  S9  Vaccinium v i t i s - i d a e a L .  lingonberry  Viburnum  high-bush cranberry  edule (Michx.) Raf.  Trees: Abies lasiocarpa (Hook.) Nutt.  alpine f i r  Betula p a p y r i f e r a Marsh  paper b i r c h  P i c e a glauca (Moench) Voss  white spruce  Picea mariana ( M i l l . ) B r i t t . , Sterns S Pogg  black spruce  Pinus c o n t o r t a Dougl. ex Loud.  lodgepole pine  subsp. l a t i f o l i a (Engelm) C r i t c h f i e l d Populus balsamifera L.  balsam poplar  Populus tremuloides Michx.  trembling aspen  Ferns:  F201  C y s t o p t e r i s t r a g i l i s (L.) Bermh.  fragile fern  Dryopteris fragrans (L.) Schott.  fragrant shield-fern  Lycopodium complanatum L.  ground cedar  References  Hitchcock, C.L. et a l . 1959. Vascular Plants of the P a c i f i c Northwest. University of Washington Press, Seattle.  In f i v e parts  Hubbard, W.A. 1969. The Grasses- of B r i t i s h Columbia. B r i t i s h Columbia Provincial Museum handbook No.9. Hulten, E. 1968. Flora of Alaska and neighbouring  territories  Stanford University Press, Stanford, California. Moss, E.H. 1959. Flora of Alberta. University of Toronto Press. Schofield, W.B. 1969. Some common mosses of B r i t i s h Columbia. B r i t i s h Columbia Provincial Museum handbook No. 28.  APPENDIX 2  S c i e n t i f i c and common names and authorities f o r mammals and birds mentioned in'the text. References include: Cowan and Guiget (1965) and Godfrey, W.E. (1966).  133 Mammals: Alces alces andersoni Peterson  Moose  Canis latrans Say  Coyote  Can i s lupus  Wolf  Linnaeus  Castor canadensis Kuhl  American Beaver  Cervus canadensis n e l s o n i Bailey  Rocky Mountain E l k  Eutamias minimus (Bachman)  Least chipmunk  Gulo luscus luscus (Linnaeus)  Wolverine  Lynx canadensis canadensis Kerr  Canada Lynx  Marmota c a l i g a t a (Eschscholtz)  Hoary Marmot  Neotoma cinerea (Ord)  Pack Rat  Odocoileus hemionus hemionus (Rafinesque)  Mule Deer  Oreamnos americanus ( B l a i n v i l l e )  Mountain Goat  Ovis canadensis canadensis Shaw  Rocky Mountain Bighorn Sheep  Ovis canadensis c a l i f o r n i a n a Douglas  C a l i f o r n i a Bighorn Sheep  Ovis d a l l i d a l l i Nelson  D a l l Sheep  Ovis d a l l i stonei A l l e n  Stone Sheep  Rangifer tarandus osborni A l l e n  Osborn Caribou  Ursus americanus P a l l a s  Black Bear  Ursus arctos h o r r i b i l i s Ord.  G r i z z l y Bear  Birds: A q u i l a chrysaetus  (Linnaeus)  Haliaeetus leucocephalus  (Linnaeus)  Golden Eagle' Bald Eagle  APPENDIX 3  Some t y p i c a l s o i l p r o f i l e s and a d d i t i o n a l s o i l s d a t a f r o m t h e N e v i s Creek s t u d y a r e a .  135  P r o f i l e description of a Mini Humo-Ferric Podzol developed under the Picea-Abies forest at s i t e #17.  Horizon  Depth (cm)  Description  L-F  5-0  Needles, mosses and woody fragments.  Ae  0-5  Light gray (10YR 7/Id)* loam; fine granular, f r i a b l e ; extremely acid; abrupt boundary  Bf  5-15  Yellowish brown (10YR 5/4d) loam; weak, medium subangular blocky; firm; extremely acid; clear boundary  BC  15-30  Grayish brown (10YR 5/2 d) loam; moderate, medium subangular blocky; firm gradual boundary  Ck  30-62  Dark grayish brown (10YR 4/2 d) loam; strong, angular blocky; very firm, mildly alkaline.  Munsel notation  136  P r o f i l e description of a Black Chernozem (Alpine Eutric Brunisol) developed under small, scattered Populus spp. and dense Elymus innovatus,  Horizon  Depth (cms)  Description  Ah  0-20  Black (10YR 2/1 d) sandy loam; moderate, fine granular; f r i a b l e ; s l i g h t l y acid; clear boundary  Bm  20-25  Dark brown (7.5 YR 3/2 m) gravelly sandy loam; weak, medium subangular blocky; f r i a b l e ; s l i g h t l y acid; gradual boundary  BC  25-46  Dark grayish brown (10 YR 4/2d), cobbly gravelly sandy loam; weak, medium subangular blocky, very f r i a b l e , neutral; gradual boundary  BCk  46-68  Dark grayish brown (10YR 4/2d) cobbly gravelly sandy loam; weak subangular blocky; very f r i a b l e ; mildly alkaline; abrupt boundary  R  68+  Limestone  137  P r o f i l e description of a Eutric Brunisol under an Elymus-Festuca plant community at s i t e ID  Horizon  Depth (cm)  Description  Ahe  0-5  Very dark grayish brown (10YR 3/2 m) loam; moderate fine granular; f r i a b l e ; medium acid; clear boundary  Bml  5-18  Dark brown (10YR 3/2 m) loam; weak, moderate subangular blocky; f r i a b l e ; medium acid; gradual boundary  Bm2  18-46  Dark yellowish brown (10YR 4/4m) loam; weak; moderate subangular blocky; f r i a b l e ; s l i g h t l y acid; diffuse boundary  BC  46-91  Very dark grayish brown (10YR 3/2m) loam; weak, fine subangular blocky; f r i a b l e ; neutral  138  P r o f i l e description of a L i t h i c Dystric Brunisol under the SileneCalamagrostis plant community at s i t e 4A  Horizon  Depth (cm)  Description  Ah  0-5  Very dark brown (10YR 2/2d) loam; moderate, medium granular; f r i a b l e ; extremely acid; clear boundary  Bm  5-15  Brown (10YR ^/3d) sandy loam; weak, medium subangular blocky; extremely acid; gradual boundary  Cl  15-20  Brown to yellowish brown (10YR 5/3.5d) sandy loam; weak; subangular blocky; extremely acid; abrupt boundary  R  20+  Yellowish brown sandstone  139 Some additional chemical and physical properties of forest and valley s o i l s at Nevis Creek ——  Available Fine Base Exchangeable Oxalate/extractable Sand S i l t Clay Clay Site Horizon Satn. Cations (mg /100g) *P(ppm) Fe(%) A l ( % ) (%) (%) (%) (%) Mg Na 16  16  Ah ACg Cl  63.80 5.54 0.52 1.57 100+ 1.98  0.02 0.01 0.01  79.1 178.2 477.1  0.65 1.16 0.76  0.11 0.08 0.10  C2 Ae  100+ 8.17  1.63 0.13  0.01 0.01  216.9 20.6  0.46 0.06  0.06 0.06  Bf  100+ 100+  0.80 0.71  0.01 0.04  427.2  1.00  0.22  8.2  0.40  0.04  14.4  0.15 0.34 0.04  0.08  BCk 12  Ae Bm BC  17  H  Al  Ah Bm BC  A2  Ahe  123.7 64.2 17.7 97.52 2.56 98.14 0.97 100+ 0.37 4.31  0.03 0.02 0.03 0.03  * Available P by the Bray #3 method  120.6 10.24 487.5 68.4  44.6 49.1 6.3  2.1  39.9 41.1 19.0 55.7 31.6 12.7  9.1 5.1  0.10 0.05 48.9 32.6 18.5 57.7 27.2 15.1 9.0 17.4 63.9 18.7 8.9  140 Some additional chemical and physical properties of alpine s o i l s at Nevis Creek Exchangeable Available Oxalate Base Cations (meg/100) *P extract Sand Site Horizon Satn. Mg Na (ppm) Fe(%) A l ( % ) (%) 10B  Clay (%)  Fine Clay (%)  39.5 16.9 30.7 24.2  8.7 13.1  36.6 41.5 21.9  11.8  Ah  115.6  46.6  BC  45.1  Silt (%)  10A  Ah  96.78  3.31  0.02  170.5 101.7  100+  0.33  0.02  55.6  44.2  41.6 14.2  3A  CBk H  100+  6.87  0.08  48.3  24.1  49.0  26.9  14.1  ID  Bm  39.4  0.50  0.19  46.1  36.7  17.2  7.2  477.7 20.7  0.26  0.10  44.6  39.6 15.8 10.3  2C  Cl Ahe Ahe Bm  10.2 14.0 357.4 18.5  0.12 0.08 0.36 0.13 0.24 0.13 0.41 0.11  2B  1C  BC Ae  0.73  4.38  0.03  Bm BC  55.77 41.49  2.18 0.76  0.04  5A  Ahe Bm  4B  Ahe Bm BC  18.26 1.02 5.57 0.09 4.37  0.02  0.02  0.04 0.02 0.02  * Available P by the Bray #2 method  7.8  11.2 0.32. 0.13 8.1 0.15 0.07 21.5 0.60 14.8 0.47  0.35 0.22  41.1 34.9  0.22 0.62  0.27 0.24  41.9 53.0  37.0 21.1 30.7 16.3  9.43 2.80  104.0 0.89  0.24  60.8  23.9 15.3  8.20  APPENDIX 4  Miscellaneous climatic data and a l i s t of instruments used to measure climate i n the Nevis Creek area.  APPENDIX 4 Monthly and annual Mean Temperatures f o r the year 1970 Station Fort St. John Airport  Mean max. 4.1 27.9 Mean min. -11.7 13.7 Mean daily - 3.8 20.8  33.6 16.2 24.9  47.7 30.0 38.9  58.2 38.6 48.4  69.8 47.9 58.9  70.8 49.0 59.9  70.1 49.0 59.6  58.0 39.7 48.9  49.2 30.9 40.1  19.5 75 13.5  Fort Nelson  Mean max. - 2.7 19.1 Mean min. -19.2 1.6 Mean daily -11.1 10.4  33.1 10.4 21.8  46.8 25.9 36.4  60.6 38.0 49.3  71.0 48.6 60.1  73.7 49.1 61.4  70.7 48.4 59.6  56.4 36.3 46.4  40.5 23.8 32.2  16.3 -1.6 40.2 2.0 -14.5 20.8 9.2 -8.1 30.6  Fort Nelson Mean max. 8.1 29.5 Churchill Mines Mean min. -3.2 15.4 Mean daily 2.5 22.5  26.5 12.2 19.4  33.5 19.0 26.3  43.1 29.0 36.1  57.2 38.6 47.9  57.1 39.9 48.5  55.2 38.6 46.9  42.7 36.0 36.9  36.0 23.2 29.6  21.5 9.2 34.9 7.4 -5.4 20.4 14.5 1.9 27.7  0  8.2 43.0 -6.1 25.4 1.1 34.2  143 Description of Canada Land Inventory Equipment  Rimco Sumner Mark II/RT Recorder: The Rimco Recorder has been adapted to the recording of temperature and r a i n f a l l i n the Canada Land Inventory Network.  The instruments are designed  to record f o r a s i x month period without being checked. Therefore, Rimco instrumentation i s most often placed i n more remote l o c a l i t i e s .  The range  of the instrument f o r temperature recordings i s from -60°F to 130°F. Rainf a l l measurement up to 400 mm/hr (15 inches/hr) can be handled. A t i l t i n g bucket raingauge (diameter 5 inches) i s placed i n a l e v e l , unobstructed position, f a i r l y close to the power source. The rate and amount of r a i n f a l l may both be determined by using this instrument. Lambrecht Thermograph: The Lambrecht Thermograph i s primarily used throughout the climatolog i c a l networks i n the i n t e r i o r .  The range of the instrument's use i s from  -30°F to +130°F. The accuracy of the thermograph i s within plus or minus 1.5% of the t o t a l range of measurement. The temperature recorded i s a function of bimetallic s t r i p s contraction and expansion. The temperature trace i s recorded on a monthly chart.  Each month the calibration of the  thermograph i s checked against a zeal minimum. The lowest temperature on the thermograph i s compared to the monthly ininimum registered on the mirLimum thermometer.  The difference between the thermograph's value and the mirumum  thermometer results i n a correction factor which i s then applied to the month's information. Kahlsico Thermograph: The Kahlsico Thermograph i s i n use throughout most of the remainder of the i n t e r i o r .  The range of the iristrument i s indicated at from -40°F to +120°F.  144 The accuracy i s similar to that of the Lambrecht thermograph. The temperature trace i s recorded on a monthly chart, and the correction factor i s calculated i n the same fashion as f o r the Lambrecht thermograph. Fuess Hygrothermograph: The Fuess Hygrothermograph records both r e l a t i v e humidity and temperature i n degrees Fahrenheit. The range of temperature the instrument i s capable of recording i s from -40°F to +110°F. The monthly correction factor i s calculated i n the same manner as the Lambrecht and Kahlsico thermographs. The instrument is:>.'reasonably accurate from 0 t o 100% f o r humidity measurement. The degree of accuracy i s from plus or minus 5% f o r a l l hygrothermographs i n use. Temperatures and humidities are recorded on a seven day chart. Zeal Minimum Thermometers: Zeal Minimum Thermometers are placed at each temperature station i n order to determine the correction factor of temperature data. Minimum temperatures are also used to determine whether the thermograph requires re-calibration.  The range of the thermometers i s from -90°F to +110°F.  Brannan Maximum Thermometers: Brannan Maximum Thermometers are s i m i l a r l y used to check the upper range of calibration of the thermographs.  Secondly, i f the minimum temperature  values are unobtainable f o r some reason, the maximum thermometer indicates to r  some degree the accuracy of the c a l i b r a t i o n .  The range of thermometers i s  from -35°F t o +120°F. Rain Gauges: a)  Rain Gauge (long storage p l a s t i c material or metal type) These r a i n gauges are twenty-four inches i n height and have a 6.115 inch  i n diameter opening. The storage capacity i s twenty inches and as a result the gauges are placed i n areas of heavy r a i n f a l l or locations which are not v i s i t e d often (six month Rimco stations f o r example).  145 b)  Rain Gauge (short type) These r a i n gauges are placed i n the majority of locations.  The  gauges are twenlve inches i n height, and are coated with a protective layer of aluminum paint.  The gauge opening i s f i t t e d with a funnel having  a 3/8 inch diameter hole i n the funnel's centre. A substantial amount of kerosene i s poured into each gauge to prevent evaporation of the r a i n which f a l l s . a + b) Rain Gauges (both types) The r a i n gauges are positioned at temperature and precipitation stations throughout network areas. The gauges are i n s t a l l e d on l e v e l ground and free from any obstruction.  This practice insures that t o t a l r a i n f a l l  catch represents f a i r l y closely the r a i n f a l l f a l l i n g i n an area. At each s t a t i o n , two r a i n gauges are established so as to minimize error and to better insure some reading w i l l be obtained.  Rain gauges are kept at the  Climatological stations during the A p r i l - May to September - October period only.  Stevenson Screen The Stevenson Screen i s a large louvered box very similar to the type used by the Atmospheric Environmental Service.  The screen houses a  thermograph or hygrothermograph, and maximum and miramum thermometers. screen i s positioned so that the thermograph's sensor i s positioned four feet above the ground and the screen door i s oriented to the north.  The  146  APPENDIX 5  A comparison of some water and acid soluble elements i n a mineral l i c k s o i l and an unrelated sample from the alpine slopes.  Related s o i l properties CEC Ca/mg r a t i o  Major elements (lbs/acres) Na P K Ca Lick sample  7 8.9  Control sample  37.2  4  173  9550  27.9  6.3  180  14125  40.2  7.7  "iMinor elements (p.p.m.) Mn Zn Cu Pb  Ni  Co  Lick sample  130.5  76.9 26.9  4.8  55.0  10.0  Control Sample  120.9  72.7 15.5 12.0  26.9  7.8  "Acid soluble extracts. Concentrations determined by t o t a l digestion using HF and HC10 . Selenium tested f o r t o x i c i t y levels only. L  T a b l e 14b: Shrub measurements f o r f o u r s i t e s i n t h e 'Elymus-Festuca  Species  SITE LA 1%  D  IB Ht. x"  Cr. D  1%  D  IC Ht. x"  Cr. D x"  5?» Potentilla Salix  Rosa  fruticosa  glauca  Betula  community  glandulosa  acicularis  9.6  9.7  0  0  ID  1%  D  Ht. x"  Cr. • D x"  1%  D  Ht. x"  Cr. D x"  85  0.9  11  9  90  1.6  7.6  3.6  12  20.5  10  tr  26  39  85  0.6  20  0.3 10.6 12.6 70  0.6  12.4  18  15  0.1  0  0  50  0.3  12  24  0  0  0  0  0  0  10  0.1  10  8  0  0  0  0  Ht = Average H e i g h t i n i n c h e s . C r . D. Average crown diwmeter i n i n c h e s Tr = trace T a b l e 14c: S o i l s u r f a c e components f o r f o u r s i t e s i n the E l y m u s - F e s t u c a SITE  S o i l Surface components bare  soil  rock litter Cryptogams ( l i v i n g ) (mosses, lichens) Phanerogams plants)  ccmmunity  (living)  IC %  TD % "  1A %  IB %  8  8  7  0  8  4  10  10  42  47  47  40  7  5  6  7  36  36  30  43  (higher  NEVIS CREEK STUDY AREA I23°I7'30"  123° 30'  57°27'30'  57 ° 27 30  L  57 °25 -\  57° 25  57°20  5 7 ° 20' 123 ° 30'  SCALE 1/2  H  131,680 2 MILES  0  KH ( part of 94G/GW  VEGETATION COMMUNITIES  SYMBOL b  lbJ  c G  3  4  GRASSLAND  • • • • • •  SYMBOL  Elymus-Festuca Elymus - Agropyron  F|  Dryas-Festuca  F  Silene- Calamagrostis Calamagrostis-Hierochloe (E-slope) Festuca-Dryas  oJ  2  ^3 4 A  F  Valley Meadow  FOREST  • •  Picea-Abies  •  Betula- Abies  •  P  North Slope Picea Betula- Pinus Populus  Betula-Vaccinium uliginosum IE S 2  B' T  STREAMSIDE  •  Pinus - Salix  SHRUB  S  SYMBOL  Betula -Vaccinium vitis-idaea Betula- Salix  Salix-Epilobium (Gravel Bar) Salix-Betula (Terrace) OTHERS  N  •  Cryptogram- Salix  R  n  Rock or Unvegetated Erosion Slope  Study site locations  

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