Land and Food Systems, Faculty of
DSpace
UBCV
Beaton, James Duncan
Master of Science - MSc
University of British Columbia
In the forest used as range several problems are encountered: (1) accessibility of ranges and (2) invasion of open or lightly timbered ranges by forest growth. For many years stockmen have advocated the use of controlled burning to overcome these problems. However, at present the value of fire for range improvement in this region is not definitely known. Experimental burns have been made to study the effect of fire on vegetation, but little or no work has been done to determine the effect of fire on the soil in such forest range areas. Accordingly, this investigation was initiated in order to determine to what extent soil characteristics in the forest range about Lac Le Jeune have been altered toy forest fires. As a result of forest fires the following changes occurred in the soil of the lodgepole pine, Douglas fir and mixed stands of lodgepole pine, Douglas fir, and spruce forests near Lac Le Jeune. (1) A reduction in percent porosity of the top O-3 inches of soil due to the destruction of both the porous organic horizon and the crumb structure of the upper portion of the B₂ horizon. A further reduction was the result of the soil pores toeing clogged toy ash and suspended soil particles. (2) Increased percentage of capillary pore space of the O-3 inch layer because of the destruction of the larger pores in the Ao horizon and the compaction of the bare soil toy rain. (3) 4 decrease in the percentage of non-capillary pore space or air volume in the O-3 inch layer resulting from the destruction of the Ao with large porese The compacting effect ofrain drops on the crumb structure of the B₂ horizon also aided in decreasing the non-capillary porosity. (4) An increase in volume weight of the O-3 inch layer due to compaction and destruction of the less dense Ao. (5) A decrease in the infiltration rate due to compaction and destruction of soil structure. (6) An increase in soil temperature at a depth of 3 inches resulting from the addition of charcoal which absorbs heat and the destruction of vegetation and forest litter which normally serve as insulating agents. (7) An increase in pH of the Ao and in some cases of the A₂ as a result of the release of basic minerals from the ash, and an Indication that the basic minerals may be leached downwards to the A₂. The pH of the Ao decreased 3 or 4 years after the fire. (8) A decrease in the organic matter content of the duff which had not been totally destroyed by fire. Below the Ao no change occurred. (9) A decrease in the total nitrogen content of the Ao due to volatilization of nitrogen during the fire. No definite trend could be established below the Ao. (10) An increase in total phosphorous in the Ao because of the release of this element from the litter. (11) A reduction in the carbonic acid soluble phosphorous in the Ao due to its combination with the excess calcium to form an insoluble compound. Similarly a decrease in CO₂ soluble phosphorous occurred in the A₂. (12) A decrease in CO₂ soluble potassium in the Ao and A₂ resulting from unrestricted leaching. An Increase in CO₂ soluble potassium in the B₂ horizon. (13) An increase in CO₂ soluble calcium in the Ao of recent burns due to the presence of large amounts of calcium in the ash. Apparently 8 or 9 years are required before ail the added calcium is leached to lower horizons. (14) An increase in CO₂ soluble magnesium in the Ao of the recent burns. The content decreased in the Ao of the older burns because of increased leaching. (15) A decrease in CO₂ soluble nitrates in the Ao. An increase in nitrates in the B₂ is probably a result of increased nitrification at the soil surface followed by considerable leaching. (16) A reduction in the base exchange capacity of the Ao. An increase in exchangeable calcium in the Ao and A₂. An increase in exchangeable magnesium in the Ao, A₂ and B₂ horizons. An increase in exchangeable potassium in the Ao, A₂, B₂, and B₃. An increase in percent base saturation in the Ao, A₂, B₂, and B₃ horizons.
INFLUENCE OF BURNING ON THE SOIL IN THE TIMBER RANGE AREA OF LAC LE JEUNE, B. C. by JAMES DUNCAN BEATON A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN AGRICULTURE i n the Department of AGRONOMY (SOILS) We accept t h i s t h e s i s as conforming to the standard r e q u i r e d from candidates f o r the degree of MASTER OF SCIENCE IN AGRICULTURE. Members of the Department of Agronomy. THE UNIVERSITY OF BRITISH COLUMBIA September, 1953. ABSTRACT In the forest used as range several problems are encountered: (1) accessibility of ranges and (2) invasion of open or lightly timbered ranges by forest growth. For many years stockmen have advocated the use of controlled burning to overcome these problems• However, at present the value of f i r e for range improvement in this region is not definitely known. Experimental burns have been made to study the effect of f i r e on vegetation, but l i t t l e or no work has been done to determine the effect of fi r e on the s o i l i n such forest range areas. Accordingly, this investigation was initiated in order to determine to what extent s o i l characteristics in the forest range about Lac Le Jeune have been altered toy forest f i r e s . As a result of forest f i r e s the following changes occurred in the s o i l of the lodgepole pine, Douglas f i r and mixed stands of lodgepole pine, Douglas f i r , and spruce forests near Lac Le Jeune. (1) A reduction in percent porosity of the top 0-3 inches of s o i l due to the destruction of both the porous organic horizon and the crumb structure of the upper portion of the B 2 horizon. A further reduction was the result of the s o i l pores toeing clogged toy ash and suspended s o i l particles. (2) Increased percentage of capillary pore space of the 0-3 inch layer because of the destruction of the larger pores in the Ao horizon and the compaction of the bare s o i l toy rain. (3) 4 decrease in the percentage of non-capillary pore space or a i r volume In the 0-3 inch layer resulting from the destruction of the Ao with large pores e The compacting effect o f r a i n drops on the crumb structure of the Bg horizon also aided in decreasing the non- \ capillary porosity. (4) An increase in volume weight of the 0»3 inch layer due to compaction and destruction of the less dense Ao. (5) 4 decrease in the i n f i l t r a t i o n rate due to com-paction'1 and destruction of s o i l structure. (6) 4 1 1 increase in s o i l temperature at a depth of 3 Inches resulting from the addition of charcoal which absorbs heat and the destruction of vegetation and forest l i t t e r which normally serve as insulating agents. (?) An increase in pH of the Ao and in some cases of the 42 as a result of the release of basic minerals from the ash 9 and an Indication that the basic minerals may be leached downwards to the A2* The pH of the Ao decreased 3 or 4 years after the fire» (8) 4 decrease i n the organic matter content of tke duff whicti had not been totally destroyed by f i r e * Below the 4o no change occurred« (9) 4 decrease in the total nitrogen content of the Ao due to vola t i l i z a t i o n of nitrogen during the f i r e . No definite trend could be established below the Ao. (10) An Increase in total phosphorous i n the Ao because of the release of this element from the l i t t e r s (11) A. reduction in the carbonic acid soluble phosphor-ous in the 4o due to i t s combination with the excess calcium to form an insoluble compound. Simillarly a decrease i n COg soluble phosphorous occurred in the Ag. (12) 4 decrease in COg soluble potassium i n the Ao and Ag resulting from unrestricted leaching* An Increase in COg soluble potassium in the Bg horizon. (13) An increase in COg soluble calcium in the Ao of recent burns due to the presence of large amounts of cal-cium in the ash. Apparently 8 or 9 years are required before a i l the added calcium is leached to lower horizons. (14) An increase in COg soluble magnesium in the Ao of the recent burns. The content decreased in the Ao of the older burns because' of increased leaching. (15) A decrease i n COg soluble nitrates in the Ao. An increase in nitrates i n the B g i s probably a result of i n -creased n i t r i f i c a t i o n at the s o i l surface followed by con-siderable leaching. (16) A reduction i n the base exchange capacity of the Ao. An increase in exchangeable calcium in the Ao and Ag» An increase i n exchangeable magnesium i n the'Ao, Ag* a n& Bg horizons. Aaa increase i n exchangeable potassium in the Ao, Ag* Bg, and B^i An increase in percent base saturation in the Ao, Ag« Bg, and B 3 horizons. ACKNOWLEDGEMENT The author wishes to express his sincere apprec-iation to Dr. D.G. Laird, Professor of Soils, and Dr. C.A« Rowles, Associate Professor of Soils, of the University of Bri t i s h Columbia, Department of Agronomy, under whose direction this study was written, for their suggestions and constructive criticism* Gratitude is extended to Mr. T.G. Wi l l i s , Superintendent, and Mr. Alastair McLean, Agrostologist, of the Dominion Range Experiment Station, Kamloops, B.C., who in many ways made this study possible. The help of Mr. William Pringle, Research Officer, Dominion Range Experiment Station, in the vegetative classification is gratefully acknowledged. The author would also like to thank Mr. Pete Chobaniuk, Draughtsman, P.F.R.A., Kamloops, B.C., for his preparation of the map accompanying this t h e s i 3 and Mr. H.L. Topham, Engineer, P.F.R.A.* Kamloops, B.C., for his assistance in obtaining the enlarged prints included in this study. TABLE OF CONTENTS Pag© ACKNOWLEDGEMENT i INTRODUCTION 11 REVIEW OF LITERATURE iv - Effect of Fire on the Amount of Unincorporated 1 Organic Matter - Effect of Fire on Physical Properties 3 - Effect of Fire on Chemical Properties 17 - Effect of Fire on So i l Organisms 29 - Conclusions from the Literature 32 EXPERIMENTAL 34 - Geology of the Lac Le Jeune Area 34 - Climate of the Lac Le Jeune Area 38 Table 1. Climatic Data for Two Stations Near 38 Lac Le Jeune Figure 1. Precipitation and Potential Evapo- 39 transpiration Curves for Knouff Lake - Location and Soils of the Lac Le Jeune Area 39 - Description of Sampling Area 42 Tables 2 - 1 1 Profile Descriptions. 44-53 - Morphological Features 54 METHODS OF ANALYSIS 56 RESULTS AND DISCUSSION 60 CONCLUSIONS 69 APPENDIX 72 Table 12 Comparison of the Results obtained by The 73 Bouyoucos Method of Mechanical Analysis and Hand Texturing. Page Table 13 The effect of Fire on the Non-Capillary Porosity, 74 Capillary Porosity, Percent Porosity and Volume Weight of the S o i l . Table 14 The Effect of Fire on the Rate of Water i n f i l t r a t i o n 75 and S o i l Temperature. Table 15 The Effect of Fire on. S o i l pH. 76 Table 16 The Effect of Fire on the Organic Matter Content of 77 the S o i l . Table 17 The Effect of Fire on Total Nitrogen in the S o i l . 78 Table 18 The Effect of *Fire on the Total Phosphorous in 79 the S o i l . Table 19 The Effect of Fire on the COg Soluble Phosphorous 80 in the S o i l . Table 20 The Effect of Fire on the COg Soluble Potassium 81 Content of the S o i l . Table 21 The Effect of Fire on the Content of COg Soluble 82 Calcium in the S o i l . Table 22 The Effect of Fire on the Content of COg Soluble 83 Magnesium i n the S o i l . Table 23 The Effect of Fire on the Content of GO2 Soluble 84 Nitrate in the S o i l . Table 24 The Effect of Fire on the Base Exchange Capacity, 85 Exchangeable Bases, and Percent Base Saturation of a Lodgepole Pine S o i l Burned in 1945 and 1951. Figure 2 An Outcrop of Coast Intrusive Granitics near 86 Rossmore Lake. Page Figure 3 Coast Intrusive Granitic Outcrop near Lac Le Jeune 86 Figure 4 Tertiary Basalt at Rossmore Lake. 87 Figure 5 Tertiary Basalt Forming a Distinct Escarpment 87 at Rossmore Lake. Figure 6 A Transverse Moraine near Rossmore Lake. 88 Figure 7 A Degraded Moraine Damming Lac Le Jeune. 88 Figure 8 A Moraine Roughly Pa r a l l e l with Lac Le Jeune 89 Figure 9 Rossmore Lake is Moraine Dammed 89 Figure 10 A. Glacial Erratic Conglomerate Block near 90 Rossmore Lake. Figure 11 A Glacial Erratic Conglomerate Block near 90 Lac Le Jeune. Figure 12 Kettle-Like Depressions in a Transverse Moraine 91 near Rossmore Lake. Figure 13 An Esker near Rossmore Lake• 91 Figure 14 A Rock Drumlin located 11 miles from Lac Le Jeune 92 Figure 15 A Rock Drumlin 12 miles from Lac Le Jeune. 92 Figure 16 1943 Burn of Douglas F i r , 93 Figure 17 Unburned Douglas F i r . 93 Figure 18 1945 Burn of Mixed Stand. 94 Figure 19 Unburned Mixed Stand. 94 Figure 20 1945 Burn of Lodgepole Pine. 95 Figure 21 Unburned Lodgepole Pine 95 Figure 22 1945 Burn of Lodgepole Pine. 96 Figure 23 1945 and 1951 Bum of Lodgepole Pine. 96 Figure 24 1951 Burn of Lodgepole Pine 97 Figure 25 Unburned Lodgepole Pine 97 Page Figure 27 Unburned Stagnant Lodgepole Pine. 98 Figure 28 The Steel Cylinder used for Determining 99 I n f i l t r a t i o n Rates Figure 29 A Weston S o i l Thermometer. 99 Figure 30 The Apparatus used f o r Determining COg 100 Soluble Minerals. BIBLIOGRAPHY. 101-113 i i INFLUENCE OF BURNING ON THE SOIL IN THE TIMBER RANGE AREA OF LAC LE JEUNE, B.C. INTRODUCTION Forests occupy 95 percent of the interior of B r i t i s h Columbia with grassland and-alpine tundra making up the remainder (136). Most of the drier and more open forested areas are valuable for range purposes and of an estimated 10 to 15 million acres of usable forest range, about 7 million acres are now being grazed (136) 0 Two of the more important problems encountered in the use of forest range are: (1) accessibility and (2) invasion of open or lightly timbered ranges by tree growth. In the Douglas F i r zone of the Southern Interior where many stands of lodgepole pine have been k i l l e d by bark beetles or by f i r e s , large areas are covered by masses of fa l l e n trees. Such locations are no longer easily grazed because of the i n -a b i l i t y of stock to move about readily and the d i f f i c u l t y i n managing herd3. At the same time the routes to more desirable range areas are frequently obstructed by these barriers. How to overcome this problem, serious as i t is In some l o c a l i t i e s , has baffled the ingenuity of Government o f f i c i a l s and ranchers alike. Some of the open or semi-open areas are being invaded by tree growth which causes a reduction In the grazing capacity of forest range. Such an Invasion may be the result of heavy graz-ing or the natural return of trees to areas deforested in the past by repeated f i r e s . For many years stockmen have advocated the use of con-trolled burning to overcome such grazing problems. There Is l i t t l e doubt that such a practice provides a means for disposing of unwanted vegetation, but at the same time sets up conditions for accelerated erosion which may result in extreme damage. Experimental burns have been provided on occasion in order to determine the merits of periodic f i r i n g but frequently the conclusions have been based largely on appearance of the subsequent vegetation rather than on changes in the s o i l i t s e l f . Thus the data as they appear in the literature are rather contradictory. This investigation was undertaken therefore in an attempt to harmonize these apparent contradictions and to determine specifically to what extent s o i l characteristics In the forest range about Lac Le Jeune have been altered by forest f i r e s . REVIEW OP LITERATURE There ia an extensive literature relative to the in-fluence of burning on forest grazing lands and yet the evidence is not conclusive insofar at least as effects on s o i l are concerned. This is unquestionably due to the di f f i c u l t y in Interpreting observations and In integrating as between the numerous factors contributing to an observed effect. In order to simplify the presentation the review of literature is being presented under the following headings: (1) effect on the amount of unincorporated organic matter, (2) effect on physical properties, (3) effect on chemical properties, and (4) effect on s o i l organisms. 1 Effect of Fires on the Amount of Unincorporated Organic Material The effect of f i r e upon the thickness of the forest floor varies Inversely with the intensity and frequency of burning (18). Alway and Rost (1), reported that in the case of severe fi r e s the mineral s o i l was exposed over extensive areas, and in single light fires the organic layers below the l i t t e r were l i t t l e affected. According to Anon (3), a series of fi r e s in the Great Dismal Swamp in North Carolina had brought about destruction of peat to a depth of 10 or more feet in places. In the Adirondacks, DIebold (27), found that as a result of f i r e s the median depth of forest floor in burned areas of the spruce-fir type was only 2 inches as compared to 14 Inches In the unburned sites. Burns (18), observed in New Jersey, almost complete de-struction of the unincorporated organic matter* Donahue (28), stated that in soils under shortleaf and longleaf pine stands the total amount of organic matter was twice as great in areas long unburned as i t was where frequent burning had occurred. Summer fire s destroyed more organic matter than did spring f i r e s . On a described loblolly pine burn E l l i o t t and Fomeroy (34), noted that a l l the surface l i t t e r was destroyed. In the places where the fi r e was the hottest only 50$ of the duff and surface root mat was burned. Over most of the area the duff remained intact. Harper (53), in a study on longleaf and slash pines noted that the dead and live vegetative cover of the s o i l was re-moved by f i r e e 2 Firey on steep mountain slopes in central Arizona com-pletely burning the needle l i t t e r and duff was observed by Hendricks and Johnson (57). Heyward et a l (62), and Heyward (65), described the differences between the organic layers under longleaf pine stands protected from f i r e for at least ten years and under stands subjected to frequent burning. As a result of frequent burning the Ao vanished on many s o i l s . On areas protected from f i r e the l i t t e r was .75 « 1.5 inches thick, with a gradual transition to an F layer .5 - 1.5 inches thick, which general-ly rested upon mineral s o i l . A thin H layer was present in a few spots. In India, Hole (69), reported that burning of grasslands w a 3 injurious owing to the destruction of a l l humus and organic debris. Isaac and Hopkins (73), showed that heavy slash fires de-stroyed 89 percent of the organic matter in the duff layer of western Washington s o i l s . In pot culture experiments with undisturbed forest s o i l , Lunt (89), showed that the Ao was removed by burning. McCuiloch (94), stated that f i r e may destroy as much as 25 tons of organic material per acre. Minckler (100), reported that in the spruce-fir type at high elevations in the Southern Appalachians, f i r e has de-stroyed the organic s o i i on certain areas removing as much as .2 feet of organic matter and leaving bare rock exposed. Studies carried out by Rideout (112), on Vancouver Island reveal that over much of the burned sites the duff layer has been completely removed. 3 Many other workers such as Arend (5), Chapman (19), Copley et a l . (22), Powells and Stephenson (39), Frothing* ham (42), Heiberg (55), Rowe (113), Worley (148), and Elwell et a l (36), although not presenting data did recog-nize that fire destroyed unincorporated organic matter. Effect of Fires on Physical Properties The marked change brought about in the physical proper-ties of soils is largely due to the removal of unincorporated organic material and exposure of the mineral s o i l fraction to the elements. Lowdermilk (87), stated that i f the forest l i t t e r was destroyed the consequent exposure of the s o i l greatly increased the amount of eroded material and reduced the absorption rate of the s o i l . Suspended particles in run-off water from bare s o i l f i l t e r e d out at the surface and there-by sealed the pores and seepage openings into the s o i l s u f f i c i -ently to account primarily for the marked differences In the rate of absorption between bare and l i t t e r covered s o i l s . Temperatures during f i r e s . In a study of fires on the central coastline of New South Wales, Beadle (11) reported that the surface temperature varies from 81 to 213°C. At a depth of one inch the temperature does . not exceed 67°C. Under extreme conditions the temperature at a depth of 1 inch exceeds 250°C, while at a depth of 1 foot the temperature i s 43 to 50°C. The probable maximal temperature o during a severe f i r e at a depth of 1 inch is 111 - 114 C., at 3 inches 59 - 67°C. Elpatievsky et a l . (35), showed that burning of hugs, piles of slash in spruce and pine forests in Russia caused tempera-tures in the upper horizon of sandy mineral s o i l to rise .to. 260 C. (500 P.). The depth of penetration of heat into the sandy s o i l was much greater than into heavy textured s o i l . In studying the burning of heavy slash of Douglas f i r , cedar, and hemlock, Hofmann (68), observed the following temperature extremes; 30 inches above the ground, 850°P.j under 3/4 Inch of duff, 120°P.; in mineral s o i l under 1 1/2 inches of duff, o o 60 P.; and under 1 inch of exposed mineral s o i l , 75 P. Isaac and Hopkins (73), while investigating the effects of slash burning on the forest s o i l of the Douglas f i r region recorded o a maximum temperature of 1,841 P., just above the duff surface • . ' • - o The maximum temperature 1 inch below the duff was 608 F. Heyward (66), while studying s o i l temperatures in the longleaf pine region found that at a depth of 1/8 of an Inch to 1/4 of an inch, the majority of readings ranged between 150° and 175°P. These temperatures persisted for 2 to 4 min-utes after which they declined rapidly. The maximum temper-ature reached was 274°P. S o i l temperatures at the 1/2 inch depth were much lower than those at 1/8 inch. 195 P. was the highest temperature observed at the 1/2 inch level. 'At depths of 1 inch only slight increases in temperature were recorded. 'Temperatures of burned-over s o i l . In comparing s o i l temperatures of burned and unburned chaparral areas of California, Bauer (10), found the s o i l temperatures were considerably higher on the burned areas, especially in the summer months. Also in California, Hervey (59), found that burning significantly raised the temperature at the s o i l surface and also at a depth of 2 1/2 inches. Investigations by Boyce (14), point out that f i r e causes the formation of charcoal in the s o i l . The presence of charco brings about the increase in the temperature of the exposed s o i l . Isaac (72), noted that Douglas f i r seedlings were dying on recently burned areas. He stated that blackening of the s o i l surface due to burning caused greater s o i l temp-eratures. Blackening of the s o i l surface as a result of the addition of charcoal through burning was also found by McArdle and Isaac (93), to give a much warmer s o i l . With an o ai r temperature of 90 P., the average s o i l temperature on the o surface of yellow mineral s o i l was 132 P. The average temp-erature of s o i l covered with a thin layer of burned duff had o a surface temperature of 150 P. McCulloch (94), noted also that f i r e produces charcoal on the ground* The addition of charcoal is sufficient to raise the surface s o i l temperatures as much as 15 or 20 degrees above the unburnt s o i l . The effect of charcoal i n raising the s o i l temperature was also noted by Tryon (139). • . , Greene (46), observed in the longleaf pine belt that the o average maximum temperature on the burned area was 5.5 P, higher than on the unburned area. A study by Harper (53), in the long-leaf and slash pine areas showed that the s o i l temperatures rise slightly higher on a freshly burned area. Wahlenberg's (142), investigations In the longleaf pine belt point out that the o o spring temperatures to a 3 inch depth were more by 1 to '6 P. on burned s o i l s . Further work in the longleaf pine lands by Wahlenberg et a l . (144), revealed that s o i l temperatures may average as much as 5,5°P. higher for burned s o i l s , possibly largely due to the heat-absorbing capacity of charcoal. 6 Hensel (58), observed that the burnt grasslands In Kansas o at a depth of 1 inch had a mean maximal s o i l temperature 12,1 F higher than the unburned grasslands. The mean temperature was o 4.1 F. higher on the burned areas. &t a depth of 3 inches, the mean maximum temperature was 3.6°F. higher and the mean min-o imum temperature was 4.2 F. higher. Research by Isaac and Hopkins (73), revealed that f i r e changed the soil's capacity to absorb heat; At an air temp-erature of 85°F., the surface temperature of yellow mineral o s o i l may rise to 125 F© or higher. The surface temperature o of black charred s o i l may rise to 608 F, So i l temperatures In areas which had been burnt and In areas under forest were recorded by KIttredge (78). The temp- . o ... o erature at the 1 inch depth was 70 F. under forest and 90 F. in a corresponding burned over area. In the Duke forest, Pearse (103), observed that temp-eratures on the surface and at the 3 inch depth In a plot burned over at intervals for five years were more extreme than those in an adjacent undisturbed plot. Phillip s (109), studies in the savanna of South Africa showed that higher temperatures occurred during the day in the 0-6 inch layer of fired s o i l than In the non-fired s o i l ; during the night, temperatures were lower in the burned s o i l . Shirley (124), found no difference in surface temper-atures between burned and unburned plots in a jack pine stand during the second growing season after a light f i r e . An increase in s o i l temperatures as a result of burn-ing was recognized by Sims et al« (125). Moisture Relations. During an investigation of moisture relations in C a l i -fornia chaparral, Bauer (10), recorded that on burned areas moisture In the upper s o i l layers dropped below the wilting percentage during part of the growing season. In the deeper layers, moisture remained above the wilting point throughout the period. California studies by Hervey (59), show that burning did not significantly affect s o i l moisture during the growing season. Further investigations in the burned chaparral lands of California by Sampson (117), show that the moisture In the upper layer of the s o i l Is apparently depleted more rapidly in burned than in unburned chaparral because of increased evaporation from exposed surfaces and differences in vegetative cover. The level of s o i l moisture at greater depths was higher? in burned than in unburned areas. This was explained by the presumed lack of liv i n g plant roots In the lower s o i l levels of burned areas. Burns (18), found that annual burning for long periods caused slight increases in f i e l d capacity. This Increase was probably a result of added charcoal. Tryon (139), also found that charcoal has an affect on moisture relations of s o i l ; i t increased the water holding capacity of sandy s o i l but re-• ' ' ' duced that of clay. Garren (43), stated soils of frequently burned longleaf forests show lower s o i l moisture than comparable unburned . i soils* Whereas no difference in s o i l moisture was found by Greene (47), when he compared annually burned plots and un-burned plots In longleaf pine forests. Similarly Wahleriberg et a l . (144), noted no significant differences in s o i l moisture between annually burned areas and unburned areas in longleaf pine forests. Heyward (67), also working with burned and unburned longleaf pine forest soils presented data showing that the unburned soils were moist at the 0-2 inch and 4-6 inch depths. In the unburned soils there was as much as 52 percent more moisture ih the 0-2 Inoh depth.- Heyward stated that there were no differences in wilting percentage and in moisture-holding capacity between these burned and unburned s o i l s . Alway and Rost (1), found no significant effect of f I r e upon the moisture equivalent of the burnt mineral s o i l . Work done by Eden (31), In the English heathland demonstrated that moisture in the surface s o i l of burned areas was less than In unburned s o i l s , whereas in the lower horizons the burned s o i l was more moist than the unburned s o i l . In. the Leningrad region, burned soils generally were found to have more moisture than the unburned soils accord-ing to studies by Gulisashvill and Stratonovitch (49). Studies by Hofmann (68), in the Pacific Northwest revealed that fire had a drying effect on the s o i l . The moisture content of burned soils was reduced in the mineral so i l at a depth of one inch and in the mineral s o i l under 3/4 had 1 1/2 inches of duff. Similarly a reduction in moisture holding capacity and f i e l d capacity in the Douglas f i r regions was reported by Isaac and Hopkins ,(73), to be a result of burning. The moisture contents in soils under forests and under burns 24 hours after a rain were compared by Kittredge (78). Under forest the moisture content was 26.8 % while the s o i l • i . . Under burns contained 24.7,$ moisture. Phi l l i p s (109), stated that in evergreen forests in South Africa f i r i n g conserved moisture in the s o i l below the 0-6 Inch layer but that losses of moisture from the upper 6,vinches of burned s o i l were considerable. However in the savanna type (grassland containing scattered trees) f i r e s reduced the moisture content of the upper 6 Inches of s o i l and did not alter the moisture content of the layers below. Rideout (112), observed that there was a reduction In the moisture holding capacity of the surface s o i l immediately following burning. Texture and Structure Auten (7), established the fact that forest soils lose J . • their porosity when the l i t t e r has been removed by f i r e . Further studies by Auten (8), in the Ozarks substantiated the foregoing finding. He explained the loss of porosity i n the s o i l as being a result of compaction of the bare surface s o i l which occurs during r a i n f a l l and by the sealing of s o i l pores as the finer particles are washed downward. Research by Burns (18), In the New jersey pine barrens showed that burning did birng about a slight compaction of the s o i l . Demmon (26), in discussing forest fi r e s In the longleaf pine regions stated that the s o i l surface of the frequently burned longleaf pine areas was considerably more compact than that of adjoining un-burned areas. In the Appalachian region, Frothingham (42), 10 found that after a f i r e the s o i l became compacted. Garren (4,3), reported that more massive structure was, brought about by burning in the longleaf forests. The frequently burned longleaf pine forest soils had less penetrability than the unburned s o i l s . Heyward and Tissot (63), found that in unburned longleaf pine regions the s o i l was more penetrated by holes.and thus more aerated as compared to the more compact and less porous s o i l of frequently burned areas. Lunt (88), showed that whenever l i t t e r was removed, compaction of the s o i l occurred. Compaction could result within a period of 2 1/2 years. The effect of ashes in sealing the s o i l pores after burns in the Rocky Mountains was recognized by Prledrich (40). In a comparison, of forest, open, and burned so i l s , Kittredge (78), observed that in unburned regions the s o i l had a more porous struc-ture. Kotok (80), noted that forest l i t t e r maintained the porosity of the surface s o i l . Whereas removal of the l i t t e r by f i r e brought about a decrease i n porosity. Observations of burns in woodland-chaparral vegetation by Rowe (113), show that burning brings about destruction of surface s o i l struc-ture due to plugging of s o i l pores. The effect of highly alkaline a 3 h oauslng deflocculation of the s o i l granules was noted by Sims et a l . (1.25).. Rain carried the dispersed s o i l particles into the s o i l pores oauslng clogging. 4s time goes by the s o i l is compacted to a considerable degree. Trimble and Tripp (138), in describing,the effects of f i r e on s o i l structure in the Northern Rocky Mountains pointed out that the sun and the rain baked and sealed the unprotected s o i l surface. The s o i l was puddled or compacted due to the destruction of the porous organic matter In the upper horizons, a According to Craddock .(24), f i r e reduced the colloidal content of the upper inch of s o i l in the chaparral regions of C a l i f o r n i a . . . Another study In the longleaf pine regions by Heyward (64), showed that unburned soils were one to five times softer than the same s o i l when burned frequently. Wahlen-berg (143), also studying the longleaf pine regions observ-ed that s o i l protected from fi r e for 7 years were less dense and more porous than the burned s o i l s . On the burns on Vancouver Island Hideout (112), reveal-ed that burning brought about migration of colloidal organic matter and clay particles to the subsoil while Godwin (44), observed that varying intensities of burning have, had no apparent effect in breaking down s o i l structure. Although no data was presented, Isaac and Hopkins (73), stated that burning of slash caused an unfavourable change In the structure of underlying s o i l . Failure of teak to make growth was attributed by Laurie (82), to unsuitable physical condition of the burnt over, hard baked s o i l s . Most of the workers recorded detrimental effects of f i r e upon the s o i l texture and structure, however the following investigations contradicted these findings: Edwards (32), in his studies in India found that heat produced good t i l t h as did Topham (137), in Central Africa. Observations by Ehrenberg (33), revealed that clay soils were more friable 12 and their penetrability was increased when high temperatures and certain conditions were combined. These same beneficial Effects were recognized by Jamwal (75), when heavy clay soils were burned, Sreenivasan and Aurangabadkar (127), reported that on heavy soils after a f i r e , the clay content of the s o i l was less than before the heat was applied; the colloids were, apparently aggregated by the higher temperatures. Similarly Stepanov (128), noted that baking of small s o i l particles into lumps was an effect of high temperatures during f i r e s ; these lumps could not be broken.up by the usual methods of mechanical analysis, Indicating that s o i l texture was changed* Volume - Weight Investigations by Auten (7), comparing the volume-weights of burned forest soils and undisturbed forest soils showed that in the upper six inches the burned s o i l was 25 percent heavier. Burns (18), reported that annual burning for long periods in the New Jersey pine barrens caused slight decreases in volume-weight and a i r capacity of mineral s o i l . In the longleaf pine regions Heyward (64), reported that the volume-weight of the unburned soils was commonly less than 1 while the volume-weight of the burned soils was between 1.2 to 1.6. According to Kittredge (78), the volume-weight of the upper two inches of a burned s o i l was 1.38 while the volume-weight of the upper two inches of the adjacent forest s o i l was 1.12. Lunt (88), stated that with removal of forest l i t t e r an increase in volume-weight resulted. Soils i n the New Jersey pitch pine plains which owed their existence to fi r e s were reported by Lutz (91), to have higher volume-weights than the soils of the forested regions, Infiltration Rate Measurements made by Arend (4), showed that the in-f i l t r a t i o n rate of loam soils In the Ozark Mountains of Missouri was lowered 38 percent on the average by annual burning. Another study in the Ozarks by Auten (8), showed that burned soils have a reduced capacity for water absorp-tion. The rate of absorption with each successive applica-tion of water decreased much more rapidly in the burned soils than in the unburned. A substantial decrease in the rate of i n f i l t r a t i o n with annual burning for long periods of time was recorded by Burns (18), An Immense reduction in the absorptive capacity of the s o i l was found by Love joy (86), to be a result of forest fires in the North Lake States. Meginnis (97), ob-served that the s o i l in an oak forest in Mississippi protect-ed from fi r e for at least eight years had a much greater absorptive capacity for r a i n f a l l than did the s o i l in a nearby scrub oak area which had suffered damage from logging and frequent f i r e s . Johnston (77), -stated that the i n f i l t r a t i o n rate of a burned s o i l i n Colorado was 40 percent less than the In f i i t r a tion rate of undisturbed s o i l . The i n f i l t r a t i o n rates of 14 undisturbed forest s o i l were recorded by Kittredge (78), to be four times that of burned s o i l . SIma et a l . (125), found that the f i r s t application of i n f i l t r a t i n g water entered the undisturbed forest s o i l three to four times faster than the water that entered the burnt s o i l . Upon the fourth applic-ation of water, entry was achieved six t o t en times faster on the unburned soils than on the corresponding burned s o i l s . Observations by Rowe (113), In woodland-chaparral veget-ation revealed approximately 94 percent reduction In the i n f i l t r a t i o n capacity of the s o i l on annually burned plots Further study in the chaparral lands of California by Sampson (117), demonstrated that unburned soils have i n f i l t r a t i o n capacities three times that of the corresponding burnt areas. Several workers presented data which opposed the viewpoint that f i r e reduced i n f i l t r a t i o n rates. Work done in California quoted by Madson (95), had definitely shown that denudation through burning doe8 not produce undesirable change in the Infiltration capacity of the s o i l . Studies by Veihmeyer and Johnson (141), also In California revealed that the In f i l t r a t i o n capacity of the s o i l under burned brush was not impaired toy burning. Runoff and Erosion -In California, LOwderrailk (87), stated as did Love and Jones (85), that destruction of the forest l i t t e r and the. con-sequent exposure of the s o i l greatly increased the amount of eroded material and the amount of s u r f i c i a l runoff. Plummer (110), also in California, observed that after a f i r e a disastrous flood occurred which was the result of a heavy rain f a l l i n g on the exposed surface. Another study in California by Eaton (30), 15 demonstrated that runoff increases following a severe f i r e . and that the rate of erosion of.sp.il increased as much as 30 times by burning. . Priedrich (40), observed, that a, summer, thunderstorm f a l l i n g on an area in the Rocky Mountains which was severely burned a year before, gutted stream channels and carried away top soil.. Adjacent unburned,areas also in the path of the storm, remained,unharmed. In the lodgepole pine of the same area, Trimble and Tripp (138), reported that burning even on gentle slopes brings about sheet erosion as a result of the increased and accelerated runoff. A decided increase in erosion with either an. increase in > slope or an increase in intensity of burn was observed, in Idaho by Connaughton , (21). On steep lower south slopes in Northern Idaho a washing away of the finer loam and s o i l particles leav-ing a relatively large proportion of rock and gravel was at-tributed by Larsen (81), to be a result of f i r e . Investigations in Central Arizona by Hendricks and John-son (57)v showed that on slopes in burnt over areas runoff and so i l loss occurred, while none occurred on adjacent unburned areas. On the contrary Humphrey (71), in Southern Arizona observed that the burning of velvet mesquite, burroweed, and choila areas decreased erosion. Bennett (12), comparing unburned and burned scrub oak woodland in Oklahoma noted that on the unburned plot the run-off amounted to .08 percent of the total precipitation and . .01 tons of s o i l per acre was washed off. Meanwhile on the burned plot runoff comprised 2.43 percent of the total prec-ipitation and the washoff was .15 tons of s o i l pe.r acre. Sheet erosion according to Arend (4), removed from 0 - 2 5 percent of the topsoil following annual burning In Missouri. Further studies,on erosion and runoff by Kotok (80), reveal-ed that as a result of burning and removing the forest l i t t e r ; surface runoff on burned plots was 3-30 times that of adjacent unburned areas; erosion on burned surfaces exceeded that from l i t t e r surfaces by 50 to 3000 times. The following Investigators noted that burning Increased runoff and erosions Brown (15), in a study of burning a chaparral-covered watershed, Bruner (16), in Arkansas, Copley et a l . (22), in the Central Piedmont region, Demmon (26), in the longleaf pine region, Elwell et a l . (36), in Oklahoma, Graves (45), LoveJoy (86), in th© North Lake States, Lutz (92), in Alaska, McCuiloch (94), Pardee (102), Rutledge (115), and Sims et a l . (125). A study by Pechanec and Stewart (104), concluded that s o i l losses from planned burning were light and that s o i l movement was accelerated to some extent immediately after burning. On steeper slopes r a i n f a l l runs rapidly from ex-posed s o i l and carries with It the valuable surface layers. Recurrent burning was found to intensify these losses. 17 E f f e c t of F i r e s on Chemical P r o p e r t i e s The l i t e r a t u r e i s c o n t r a d i c t o r y i n r e s p e c t t o t o t a l n i t r o -gen f o l l o w i n g b u r n i n g . The f o l l o w i n g i n v e s t i g a t o r s r e p o r t e d decreases i n t o t a l n i t r o g e n : Alway and Rost ( 1 ) , Alway and M c M i i l a r ( 2 ) , B a r n e t t e and Hester ( 9 ) , Bruner (16), Burns (18), E l w e i l et a l . (36), Graves (45), Isaac and Hopkins (73), Kivekas (79), Leningen (84)., Lovejoy (86), Luta (91), Osborn (101), and Sims e t a l . (125). Opposing t h i s c o n c l u s i o n are : Burns (18), Demmon (26), G a r r e n (43), Greene (46), Heyward (64), Heyward and B a r n e t t e (61), Lunt (89,90), Rideout (112), Wahleriberg (142) and Wah-l e n b e r g e t ai» (144), who r e p o r t e d i n c r e a s e s i n t o t a l n i t r o g e n . Many of these workers s t u d i e d f i r e s i n the l o n g l e a f p i n e f o r e s t s of Southern U n i t e d S t a t e s where i t has been r e p o r t e d t h a t grasses and legumes are more abundant f o l l o w i n g a fire© Such v e g e t a t i o n i s r e c o g n i z e d as b e i n g a b l e to i n c r e a s e the t o t a l n i t r o g e n content o f s o i l s . An I n v e s t i g a t i o n i n Minnesota by Alway and Rost ( 1 ) , demon-s t r a t e d t h a t there was a r i s e i n pH i n the top 3 inches o f the burned f o r e s t s o i l , i n the 4-6 i n c h s e c t i o n no change was r e -corded. The r e l e a s e of lime and magnesia i n the ash was respons-i b l e f o r the r i s e i n pH. In the burnt f o r e s t n i t r o g e n was o n l y .02 p e r c e n t lower than the c o r r e s p o n d i n g unburned f o r e s t . Alway and M c M i i l a r d o i n g f u r t h e r work i n Minnesota ( 2 ) , s t a t e d that a l l n i t r o g e n i s l o s t when o r g a n i c matter b u r n s . Under some c o n d i t i o n s t h i s l o s s may amount to s e v e r a l hundred l b s . per a c r e . The s o i l on an i s l a n d w i t h a v i r g i n pine cover was compared _ ' :. . .. — , 18. by Barnette and Hester (9), with mineral s o i l on the nearby Florida mainland where the area had been burned almost yearly for 42 years. The loss of nitrogen and organic matter per acre per year on the burned s o i l was estimated to be 27 lbs. and 2088 lbs. respectively. Samples from the unburned areas had a lower pH than those from the burned areas. The exchangeable lime was higher in the upper one inch and lower below one inch in the burned s o i l than in the unburned s o i l . In New South Wales, Beadle (11), found that fires i n eucalyptus forests that had not been burned for over six years did not bring about any marked change i n pH or loss-on-ignition of the underlying mineral s o i l . A study of fi r e s In Arkansas by Bruner (16), pointed out that woods humus has the capacity to build up and maintain s o i l f e r t i l i t y by constantly supplying nitrogen, phosphorous, and potassium* By destroying the woods humus, forest f i r e s rob the s o i l of nitrogen and other nutritive elements* In a comprehensive study of the effect of f i r e s on the s o i l in Hew Jersey, Burns (18), presented data Indicating that burning every four years or two annual burns decreased the per-centage of nitrogen and weight of nitrogen per unit area. Annual burning for long periods of time brought about increases in pH, organic matter, nitrogen, exchangeable calcium and exchangeable potassium i n the A horizon. No deterioration in nitrogen content was detected by Chapman (19), in samples of mineral s o i l taken from the upper horizon in annually burned loboily pine stands* According to Craddock (24), f i r e reduced the organic 19 matter content of the upper inch of s o i l i n the chaparral regions of California. Fire increased the amount of nitrate nitrogen when analyzed i n a 1:1 water extract solution. Annually burned longleaf pine soils were found by Demmon (26), to contain slightly more calcium and nitrogen than simi-l i a r soils unburned for 10 years or more. Fire also reduced the acidity of the s o i l . Investigations by Eden (31), i n the English heathland showed that burning brought about no great increase i n pot-assium. An increase in lime in the 0-1* portion was recorded. There was a possible loss of organic matter i n the upper 1 inch portion of s o i l . Edwards (32), working i n India stated that burning vegetation returns to the s o i l a l l the mineral elements taken out of the s o i l by the plants during l i f e . The small volume of ash can as a rule become easily incorporated with the sur-face layers of the s o i l and provided that there i s no erosion or excessive r a i n f a l l , leachings w i l l wash the soluable contents of the ash into the s o i l . Elpatievsky et a l . (35), noted that the effect of burning was to increase the pH of the surface s o i l . The effects of burning pasture and woodland annually in Oklahoma were shown by Elwell et al© (36), to be a loss of nitrogen and the destruction of organic matter. Research by Eneroth (37), in Sweden demonstrated that the pH values of humus layers on similiar soils are on the average higher in the burned clearing than in unburned clearings. The variations maybe as much as 1 pH unit or more. The change in 20 pH with burning was found to remain stationary for several years after the f i r e . The CaO content was higher i n the upper humus layers from the burned clearings except in the very oldest clearings. On the average the CaO content was higher in the lower humus layers from burned clearings except i n the youngest clearing. Finn (38), burned organic matter that had been placed upon sandy s o i l and upon loamy s o i l i n boxes. Immediately after the organic material had been ignited the boxes were placed i n the open. The pH was changed from acid to alkaline by burning, however at the end of one year the s o i l reaction had again become acid. As rain f e l l upon the boxes leaching and the consequent loss of nitrate, calcium and potassium occurred. Powells and Stephenson (39), stated that burning and the resulting formation of basic ash materials increased n i t r i f i c a -tion and resulted i n an increase in the soluble mineral; constit-uents of the s o i l . Fire destroyed the humus layer and some of the humus near the s o i l surface. A study by Frothingham (42), i n the southern Appalachian region showed that when l i t t e r is burned i t s mineral content is l e f t behind as an ash which i s quickly dissipated by leaching and washing out. In summarizing the effects of f i r e on the s o i l i n the South-eastern United States, Garren (43), stated that burning results in decreasing a c i d i t y , increased nitrogen, increased calcium and organic matter in longleaf pine s o i l s . The return of minerals in ashes and greater growth of legumes and herbs on burned over 2 1 areas contribute to these changes* On Vancouver Island, Godwin (44), recorded that burning brought about an immediate increase in available nitrates and a change toward alkalinity in the H ion concentration* The loss of s o i l nitrogen with burning was noted by Graves (45). Burned soils i n the longleaf pine region were found by Greene (46), to contain more total nitrogen and more organic matter than the corresponding unburnt s o i l s . These differences were explained by the greater number of grasses and legumes on the burnt areas. G r i f f i t h (48), set up experiments in an effort to separate the effects of slash burning into two classes: (1) effects of the heat of the f i r e , and (2) effects of the addition of ash. After burning there was an Increase of pH in the upper 3 inches of s o i l which was apparently due to the addition of alkaline ash. Following burning an increase in nitrate was recorded which was also due to the effects of the ash* Fire had no effect on incorporated organic matter or on loss-on-ignition. Haig (50), recognized that f i r e destroyed organic matter. Burning immediately released in the ash a considerable quantity of available nutrients. One benefit obtained by burning was the neutraliz ation of organic acids. A decrease in acidity of the surface layers i n a heath s o i l with burning was recorded by Haines (51). The amount of soluble salts increased immediately after the f i r e . During the follow-ing months these added salts were leached out of the surface s o i l * Hardon and White (52), found that burning of slash and the consequent additions of ash changed an acid, base-unsaturated 22 s o i l to a s o i l almost base saturated and nearby alkaline in reaction. The amounts of acid soluble potash and phosphoric acid were increased. The experiments of Heiberg (54), demonstrated that i t was unlikely that f i r e could cause much damage to incorporated organic matter. In another art i c l e Heiberg (55), stated that as a result of f i r i n g , part or a l l of the organic matter on top of the s o i l i s destroyed with the consequent release of available minerals from the ash. In California, Hervey (59), showed that a single burning of annual-plant communities did hot significantly affect the amount of organic matter in the top inch of the soilo According to Hess (60), i n Switzerland, where the s o i l was acid, burned over spots had a much higher pH and more calcium carbonate than unburned spots; the reaction of neutral soils was very l i t t l e affected by f i r e s . Investigations by Heyward (64), pointed out that i n the burned longleaf pine areas the s o i l is slightly less acid and has more replaceable Ca"H" More organic matter and total nitrogen were observed on the burned site s . Heyward and Barnette (61), noted that soils from burned areas i n the longleaf pine region showed pH values ranging from •15 to .48 pH units higher than those of unburned areas. Re-placeable calcium totalled as much as 101 percent more than on the unburned s o i l s . Total nitrogen differences were from small changes up to 14 percent more i n the areas subjected to burning. Hosklng (70), in a series of experiments demonstrated that when organic matter was heated for a few hours at 100 C°or 212°P 23 o a p p r e c i a b l e l o s s e s o c c u r r e d . Up to 200 G h e a t i n g r e s u l t s i n e s s e n t i a l l y d i s t i l l i n g o f f the v o l a t i l e c o n s t i t u e n t s * Isaac and Hopkins (73), i n a comprehensive study of b u r n i n g i n the Douglas f i r r e g i o n r e v e a l e d t h a t the b u r n i n g o f s l a s h brought about a pronounced change i n the chemical p r o p e r t i e s of the d u f f and the u n d e r l y i n g m i n e r a l s o i l . The t h i c k n e s s of the d u f f l a y e r averaged about 1.5 i n c h e s . A n a l y s i s shoved t h a t the d u f f on the average a c r e , e s timated to t o t a l 32 t o n s , contained approximately 28 tons o f o r g a n i c matter, 594 l b s . o f n i t r o g e n , 76 l b s . of phosphorous, 555 l b s . of c a l c i u m , and 121 l b 3 . o f potassium. The u s u a l heavy s l a s h f i r e r e s u l t e d i n almost complete d e s t r u c t i o n of the d u f f l a y e r . Burning appar-e n t l y caused; (1) a l o s s of 25 tons (89 p e r c e n t ) o f t he o r g a n i c matter c o n t a i n e d i n the d u f f . (2) a change i n d u f f r e a c t i o n from pH 4.95 to a pH of 7.6. (3) the escape o f approximately 435 l b s . of n i t r o g e n p e r a c r e . (4) an i n c r e a s e i n t h e supply of a v a i l a b l e potassium, c a l c i u m and n i t r a t e i n the d u f f and i n the 0-3 i n c h l a y e r . (5) an i n c r e a s e i n t h e weight o f water s o l u b l e s a l t s i n the d u f f and i n the 0-3 i n c h l a y e r . (6) a decrease i n a v a i l a b l e phosphorous i n the d u f f . The i n c r e a s e s i n a v a i l a b l e p l a n t n u t r i e n t s r e s u l t e d f r o m the d e p o s i t i o n a t the s u r f a c e , In h i g h l y s o l u b l e form, o f p a r t o f the n u t r i e n t s present i n t h e d u f f . S e r i o u s subsequent l o s s e s by l e a c h i n g appeared p r o b a b l e , and (7) an i n d i c a t e d l o s s of a c o n s i d e r a b l e p a r t o f the m i n e r a l n u t r i e n t s c o n t a i n e d i n the d u f f , presumably c a r r i e d o f f i n smoke. A n a l y s i s of the d u f f r e v e a l e d that t h e r e was an i n c r e a s e i n the percentage o f m i n e r a l n u t r i e n t s due to the l o s s of o r g a n i c matter and n i t r o g e n , however because some 24 o f the m i n e r a l s r e l e a s e d from the d u f f were c a r r i e d away i n smoke a decrease i n the t o t a l q u a n t i t y of m i n e r a l n u t r i e n t s o c c u r r e d . Table IV R e a c t i o n of Wind R i v e r s o i l b e f o r e and a f t e r a heavy s l a s h f i r e . # R e a c t i o n Sample Before P i r e A f t e r F i r e Duff 4.95 ^ 7.6 M i n e r a l s o i l a t a depth o f : 0-3 inches 5.0 6.2 3-6 Inches 4.8 5.5 6-12 inches 5.0 4.9 12-30 inches 5.15 5.2 Table V Q u a n t i t y and Compost i o n of r e s i d u e of samples of Wind R i v e r s o i l a f t e r i g n i t i o n . # Sample Weight of Ash S i l i c o n D i o x i d e N u t r i e n t s i n Terms i n terms o f i n Terms of o f T o t a l Weight of T o t a l Weight T o t a l Weight S o i l o f S o i l o f Ash ' P e r c e n t Percent Phosphorous Calcium Potassium Percent Percent P e r c e n t D u f f ' Before S l a s h 13.26 69.5 .115 .81 .177 F i r e A f t e r S l a s h 50.96 80.7 .121 1.80 .306 F i r e R e s u l t s o f the Neubauer t e s t i n which a chemical a n a l y s i s i s made o f s e e d l i n g s grown on a sample of the s o i l d i l u t e d w i t h pure sand shows s t r i k i n g l y t h a t the f i r e had g r e a t l y I n c r e a s e d the q u a n t i t y of calcium and potassium a v a i l a b l e but had o n l y s l i g h t l y a f f e c t e d the phosphorous. T h i s agrees w i t h the r e s u l t s o f t h e chemical t e s t s on a v a i l a b i l i t y o f n u t r i e n t s . # Isaac and Hopkins (73) 25 f a b l e VT Quant i t l e a o f w a t e r - s o l u b l e s a l t s and of o t h e r p l a n t n u t r i e n t s a v a i l a b l e i n Wind R i v e r s o i l b e f o r e and a f t e r a s l a s h f i r e . # Sample Water S o l u b l e H i t r l c A c i d S o l u b l e S a l t s S a l t s . P.P.M. .. Before F i r e A f t e r F i r e Before F i r e A f t e r F i r e P K Ca H0 3-N p K Ca H0 3-D u f f 1116 1330 4 4 2 0 2 5 5 3 M i n e r a l S o i l At a Depth o f 0-3 inches 370 535 0 0 0 1 0 1 2 4 3-6 inches 365 345 0 0 0 © © 1 0 © 6-12 inches 164 222 0 0 0 0 1 Q 2 12 -30 inche a 82 142 2 1 0 © 2 1 1 0 The e x t r a c t i n g s o l u t i o n used was *2H n i t r i c a c i d s o l u t i o n . E x p l a n a t i o n : 0«nonej l * a t r a c e ; 2«poor; 3 n f a i r ; 4«good; 5«excellent; 6 s e x c e s s i v e . # Isaac and Hopkins (73). J o f f e ' s (76), i n v e s t i g a t i o n i n the p i n e b a r r e n s I n d i c a t e d t h a t p e r i o d i c c o n t r o l l e d b u r n i n g reduced a c i d i t y i n the s u r f a c e s o i l * K i v ekas (79), i n F i n l a n d found t h a t b u r n i n g had f a v o u r a b l e e f f e e t s on the chemical p r o p e r t i e s o f m i n e r a l s o i l * As a r e s u l t of f i r e s the pH i n c r e a s e d while h y d r o l y t i c a c i d i t y and exchange a c i d i t y decreased* A l t h o u g h the n i t r o g e n content was lower, ex-changeable c a l c i u m , exchangeable potassium and a v a i l a b l e phos-phorous were more abundant i n burned s o i l than i n unburned s o i l * These changes o c c u r r e d at both the 0-5 a n d 5-10 centimeter depth* S o i l f e r t i l i t y e v a l u a t e d by the growth of oats was a t a h i g h e r l e v e l i n burned than i n unburned s o i l * Research by Leningen (84), i n Germany, showed t h a t the burn-i n g o f f o r e s t humus cover r e s u l t s i n the l o s s o f n i t r o g e n * I t was p o i n t e d out that the a l k a l i n e a s h may have d e t r i m e n t a l e f f e c t s on t r e e growth* The pure a s h produced d u r i n g the f i r e c o n s i s t s of approximately 30 percent CaO. Burn i n g o f the f o r e s t s i n the North Lake S t a t e s was ob-served b y Lovejoy (86), to r e s u l t i n the l o s s o f n i t r o g e n and o r g a n i c matter. A pot c u l t u r e experiment used by Lunt (89), demonstrated that the removal o f the Ao by burn i n g tended to i n c r e a s e the amount of a v a i l a b l e n u t r i e n t s , t o t a l n i t r o g e n and o r g a n i c matter B u r n i n g o f the Ao was r e s p o n s i b l e f o r an i n c r e a s e i n pH and lo w e r i n g o f the c o n d u c t i v i t y . D e s t r u c t i o n o f the Ao by f i r e r e s u l t e d i n a l o w e r i n g o f the s o l u b l e i r o n and ammonia c o n t e n t . Lunt (90), i n a d e t a i l e d study o f b u r n i n g i n C o n n e c t i c u t , found t h a t w i t h burning the pH of t h e Ao and A i r o s e * Ammonia n i t r o g e n , a v a i l a b l e phosphorous, and exchangeable potassium of the Ao were co n s p i c u o u s l y absent* I t was thought that the phosphate r e l e a s e d had been converted to i n s o l u b l e i r o n and aluminum phosphates* The exchangeable potassium had been l e a c h -ed out i n s o l u b l e form* Other t e s t s showed t h a t b u r n i n g r e s u l t -ed i n a h i g h e r pH, i n c r e a s e i n t o t a l n i t r o g e n , i n c r e a s e i n o r g a n i c carbon and a v a i l a b l e phosphorous i n the A h o r i z o n * A s e r i e s of t e s t s made on a p o d s o l - mor t y p e o f s o i l I n d i c a t e d that b u r n i n g the Ao r e s u l t e d i n an i n c r e a s e i n pH, i n c r e a s e s i n exchangeable c a l c i u m , t o t a l n i t r o g e n and o r g a n i c matter con-t e n t of the h o r i z o n . A c c o r d i n g t o Lutz (92), n i t r o g e n and o r g a n i c matter had been d e s t r o y e d as a r e s u l t o f f i r e s which gave r i s e to the New J e r s e y p i t c h p i n e p l a i n s * The e f f e c t o f b u r n i n g i n i n c r e a s i n g the pH of the s u r f a c e s o i l was noted by M a r s h a l l and A v e r i l l (96). Milne (99), favoured burning because the C:N ratio was lowered. It was found by Osborn (101), that the burning of l i t t e r after harvests in South Africa caused a loss of organic matter and nitrogen in the 0-2 inch layer of clay s o i l and of a loam s o i l . Perry (107), indicated that burning of a hardwood forest in Pennsylvania brought about a temporary decrease in acidity» Burned s o i l had lower values for loss-on-ignition than samples from an unburned area. Another study was carried out by Perry and Coover (108), i n the same area. Frequently burned areas had lower values for loss-on-ignition but had about the same pH in the A horizon as infrequently burned areas. Burning seem-ed to bring about an Increase in the pH of the B horizon. A study of burning on Vancouver Island by RIdeout (112), revealed a gradual increase i n surface s o i l pH with an increase in exchangeable hydrogen in the subsoils of burned sites. An i n i t i a l increase i n exchangeable base content of the burned surface s o i l was noted. An increase in magnesium and potassium in the subsoils of burned sites occurred as a result of leaching these elements from the accumulated ash. In the surface of the burned s o i l an i n i t i a l increase in phosphorous content was found. The ammonia content increased i n both surface and subsurface soils as a result of burning. Increased n i t r i f i c a t i o n and a loss of nitrate by leaching was brought about by f i r e . An Increase i n total nitrogen content and a consequent decrease"in the carbon: nitrogen ratio of the subsoil. The effects of charcoal being added to the s o i l after a f i r e was recorded by Salisbury (116). Closely associated with the a d d i t i o n s o f c h a r c o a l * an i n c r e a s e i n pH, n i t r a t e s and carbonates was observed* In the c h a p a r r a l r e g i o n s o f C a l i f o r n i a , Sampson (117), recorded t h a t much of the potassium added t o the s o i l i n the ash was leac h e d away* Changes In pH were s l i g h t * The n i t r a t e content o f the upper s o i l l a y e r o f p r a c t i c a l l y a l l c h a p a r r a l r e g i o n s s t u d i e d was h i g h e r on f r e s h burns* S c h r e i n e r et al« (120), p o i n t e d out t h a t n i t r o g e n o u s m a t e r i a l s may be added to the s o i l as a r e s u l t o f b u r n i n g . Experiments by Seaver and C l a r k (121), showed t h a t the amount of s o l u b l e o r a v a i l a b l e m a t e r i a l i n the e x t r a c t o f a heated s o i l i s i n c r e a s e d approximately 6-10 times that of the unheated s o i l . The l o s s o f n i t r o g e n by b u r n i n g and the d e p o s i t i o n of a h i g h l y a l k a l i n e ash on the s o i l s u r f a c e a f t e r a burn was rec o g -n i z e d by Sims et ai© (125). 4s a ^ r e s u l t o f f i r e h e a t i n g a s o i l S r e e n i v a s a n and Aurang-abadkar (127), found a l o w e r i n g of exchange c a p a c i t y , r e p l a c e -a b l e c a l c i u m , r e p l a c e a b l e magnesium and or g a n i c matter* A l s o an i n c r e a s e i n t o t a l s o l u b l e s a l t s , r e p l a c e a b l e sodium and r e p l a c e a b l e potassium was recorded* I n v e s t i g a t i o n s by Wahlenberg (142), i n the l o n g l e a f pine r e g i o n s i n d i c a t e t h a t o r g a n i c matter and n i t r o g e n were s l i g h t l y h i g h e r on burned s o i l s . Under p r o t e c t i o n f r o m f i r e the s o i l a c i d i t y was g r e a t e r by from .1 t o *5 pH u n i t s * F u r t h e r s t u d i e s i n t h e l o n g l e a f p i n e a r e a were c a r r i e d out by Wahlenberg e t a l * (144)* Mean value s f o r the burned l a n d exceeded those f o r the unburned l a n d i n percentage dry weight 29 as follows: total nitrogen .0028 «* .0011;; loss-on-ignition .180 - .1056; and replaceable calcium .0085 * .0024. Effect of Fire on S o i l Organisms. Arend (5), in a study of burning i n the Missouri Ozarks found that annual f i r i n g caused reductions In microbiological ac t i v i t y . In Malaya, Corbet (23), studied the effect of burning on s o i l microorganisms. Plate counts of these organisms from the 1-4 inch layer of mineral s o i l were made at intervals before and after a f i r e . The number of microorganisms rose immediate-ly following the f i r e but a week afterward and for at least nine months thereafter the plate counts f e l l to the values obtained before the f i r e . Duggeli (29), while investigating In Switzerland found that the number of bacteria was not significantly affected by the mixing of spruce ashes into the mineral s o i l . According to Fowells and Stephenson (39), burning and the resulting formation of basic ash materials increased n i t r i f i c a -tion in the s o i l . Fritz (41), stated that i n the redwood regions f i r e has sometimes severely baked the top s o i l and burnt out most of r i t s r i c h supply of the important macro and microorganisms. In the frequently burned soils of the longleaf pine regions, Garren (43), found that the s o i l fauna was scarce. Freene (47), noted that the bacterial counts were higher on burned soils in the longleaf pine area. Soils of the unburned areas in the longleaf pine regions were observed by Heyward and Tissot (63), to be riddled with 30 holes and tunnels of small mammals and Insects, Such evidence of l i f e was lacking In the frequently burned sites. The Ao of the unburned soils contained 5 times as many microfaunal forms as did the ground cover of burned areas. The top 2 inches of mineral s o i l , the unburned areas had 11 times more such animals than the corresponding s o i l depth from burned areas. The groups of s o i l animals were generally the same in burned and unburned sites. Fires decreased the number of earthworms. Results of the tests by Isaac and Hopkins (73), with the bacterium Azotobacter chroococcum indicated that burning had overcome a calcium deficiency for the growth of this organism in the s o i l , either by destroying organic acids, or by deposit-ing calcium in an available form, or by both. Aspergillus made better growth when a burnt s o i l with i t s increased supply of nutrients was attacked© The results of a study by Jamwal (75), in India, indicate that f i r e , especially a severe one, k i l l s outright a i l l i v i n g organisms in the s o i l . The reduction of protozoa resulted in an increase of n i t r i f i c a t i o n . Kittredge (78), recorded that in unburned areas there were more holes and channels caused by macroorganisms than in the corresponding burned s o i l s . A slight decrease i n ammonification and a slight increase in n i t r i f i c a t i o n was attributed to forest f i r e s by Kivekas (79). In the North Lake States, Lovejoy (86), noted that fir© destroyed most of the beneficial organisms leaving the s o i l inert and unresponsive, Michaelis (98), reported that f i r e eliminated rodents which 31 had been t h r e a t e n i n g a young hardwood p l a n t a t i o n w i t h d e s t r u c -t i o n * Pearse (103), while i n v e s t i g a t i n g the e f f e c t s o f b u r n i n g over l i t t e r on s o i l animals i n the Duke F o r e s t s found t h a t t o a depth of 3 Inches many more animals were p r e s e n t i n the un-burned p l o t than i n the burned p l o t * D u r i n g a f i v e y e a r p e r -i o d the number o f earthworms i n the s o i l of the burned a r e a decreased by 50 p e r c e n t 0 Centipedes, m i l l i p e d e s and an t s a l s o d e creased i n abundance because of f i r e s * I ncreases i n n i t r i f i c a t i o n because o f f i r e s were r e p o r t e d by Remezov (111)* 4 70-80 percent r e d u c t i o n i n the a c i t i v i t y o f earthworms and burrowing I n s e c t s was found by Rowe (113), i n burned woodland-chaparral r e g i o n s * R u s s e l l (114), s t a t e d t h a t s o i l h e a t i n g o r p a r t i a l s t e r i l -i z a t i o n which might be expected t o k i l l o f f l i v i n g organisms r e s u l t s i n an i n c r e a s e i n n i t r i f i c a t i o n . The the o r y i s t h a t a f t e r h e a t i n g , the s o i l f u n g i which use up more n i t r o g e n i n t h e i r a s s i m i l a t i o n p r o c e s s e s a r e suppressed and t h e b a c t e r i a which use up l e s s n i t r o g e n i n p r o p o r t i o n t o the amount they l i b e r a t e become dominent. Probably the p r o t o z o a , enemies o f the b a c t e r i a a re more s e v e r e l y a f f e c t e d by the heat* The d e s t r u c t i o n o f microorganisms by f i r e was r e c o g n i z e d by Sampson (118). ' S e h r e i h e r et a l * (±20), r e p o r t e d t h a t a i l organisms which normally occupy a f e r t i l e s o i l are k i l l e d by heat but n i t r o -genous m a t e r i a l s are thereby l i b e r a t e d and made a v a i l a b l e * Sushkina (130), i n a comprehensive study o f n i t r i f i c a t i o n in forests found that arter burning n i t r i f i c a t i o n begins in soils where i t has been observed before and greatly increases where i t has been going on before burning„ Moderate burning of the s o i l has a more favourable effect on the n i t r i f y i n g capacity than an intense burning. In cases of moderate burn-ing the capacity for n i t r i f i c a t i o n is evident even immediately after the burning. The effect of burning upon the s o i l lasts during a period of five years. 4 running f i r e w i l l have a more favourable effect upon n i t r i f i c a t i o n than the burning of forest debris gathered in p i l e s . According to Tryon (139), the charcoal added to the s o l i during a f i r e did not affect the abundance of bacteria or fungi. Wahlenberg et al» (144). found higher bacterial counts on burned s o i l s . Conclusions from the literature. In studying the literature relative to the effects of f i r e on the s o i l , contradictory reports in the same region have been encountered. It would appear.as though a great many factors are involved and that they were not kept constant i n a l l studies. Thus i f one of the factors such as; severity of burn, season of year, slope, exposure, texture, structure, climate, vegetation and parent material, differed varying results would naturally follow. Certain effects of f i r e on the s o i l were frequently encountered in the literature. The effects which appeared to be general are summarized below.; 1. A goodly portion or a l l of the unincorporated organic matter is'destroyed. The degree of destruction depends upon the frequency and severity of burning. 33 2 a When organic matter is destroyed, nitrogen i s lo s t . 3. Seldom is the incorporated organic matter reduced through burning. Loss may occur when heavy accumulations of slash are burned. 4. S o i l temperatures are higher during the day on burned over soils than on unburned s o i l s . 5 . Burned soils had a higher volume-weight due to compaction. 6. 4 s a result of compaction these burned soils have a lower i n f i l t r a t i o n rate. 7. Runoff and erosion is greater in burned areas. 8. Burned soils are more dense and not easily penetrated. 9* The chemical properties of the upper layers of the mineral s o i l are affected by burning. The pH and the content of available nutrient ions i s increased. In the mineral s o i l organic matter and nitrogen are not greatly affected. 10. Decreases in the abundance of s o i l organisms is brought about by frequent burning. 11. Fires stimulate n i t r i f i c a t i o n . 34 EXPERIMENTAL Geology of the Lac Le Jeune Area. This area was surveyed by'Dawson (25), In 1889 and 1890 and by Cockfield (20)), in 1939 to 1944. The observations of Cockfield did not differ significantly from those of Dawson. Much of the area in the immediate vicinity of Lac Le Jeune is underlain by plutonic rocks (20), which are part of the Coast intrusives formation of Jurassic age. The surface rocks in this area are part of the Central Nicola Batholith which extends north from Nicola Lake and consists largely of granadiorite and quartz di o r i t e . It Is partly sheared and in some specimens the quartz appears as a fine mosaic and as Interlocking grains. The rock has at many lo c a l i t i e s a pronounced gnelssic structure and the enclosing rocks are shear-ed and injected with granitic material. Most of the specimens examined under the microscope showed relatively small amounts of orthoclase, with the'plagioclase feldspars ranging in com-position from oligoclase to labradorite. The ferromagnesian minerals are bio t i t e , hornblende or pyroxene, and In many of the intrusive rocks both biotite and hornblende are present. Both Dawson and Cockfield recorded extensive areas of basalt in the Lac Le Jeune area. These rocks belong to ohe Kamloops group and are assigned to the Tertiary period. The Kamloops volcanic rocks comprise a considerable thickness of rhyolites, trachytes., andesites and basalts, together with feldspar porphyries, but the group is very largely composed of basalt and basalt breccia. The rocks show a wide range of colour from white, through various shades of red, pink, mauve, brown, buff, grey, and green-to black. They are usually massive 35 and fin© grained, but are locally porphyritic and in places coarsely so* Occasionally they are so coarse grained as to resemble fine grained plutonic rocks, though when examined under the microscope small amounts of i n t e r s t i t i a l fine grained groundmass maybe seen. Dawson (25), stated that to the westward of Trapp Lake the level of the plateau rises gradually, though irregularly, t i l l the basalt rocks are found in some places at heights exceeding 4000 feet. In this region, to the north of the head of Moore Creek, the edge of the basalts often ceases to be marked by a distinct escarpment, and as the country here becomes thickly wooded their boundary i s drawn with less precision than elsewhere. The author observed several basalt escarpments close to the selected sampling areas. These escarpments reached an elevation of 4,400 feet above sea level* It was noted that the basalts presented bold escarpments facing in a southwesterly direction. As Dawson observed, the other faces were not distinct c l i f f s but descended gradually to the lower levels. Dawson and Cockfield both recognized that this region had been glaciated during the Pleistocene. According to Dawson, numerous moraine ridges often p a r a l l e l to the valley are evident in the upper part of Moore Creek, which is located to the southeast of Lac Le Jeune. The elevation of these ridges is 3500 feet. In the Meadow Creek valley which drains Lac Le Jeune numerous hillocks and transverse ridges, evidently representing 36 moraines are found. The moraines are partly buried i n hori-zontal deposits which have formed in ponds and marshes. These features are found at an elevation of about 4000 feet. Lac Le Jeune at the head of Meadow Greek (4177 feet) is held in by more or less degraded moraines which are i n part transverse to the valley but also in part para l l e l to i t . Dawson also stated that the deposits of boulder clay to the south of Ghuwels Mountain (6 miles north of Lac Le Jeune) are extensively developed and wide spread. Glacial striations at the 6000 foot level indicating ice o flow in a direction S. 35 £• were found on Ghuwels Mountain by Dawson. Cockfield recognized the Influence of glaciation i n the Immediate vi c i n i t y of Lac Le Jeune. Striations were noted on Chuwels Mountain some six miles distant and further striations were recorded one quarter of a mile from the lake. 4s well, d r i f t ridges were located closeby. In the geological report he concluded that the ice advanced from the northwest towards the southeast and south. This direction is borne out by the scattering of blocks of conglomerate across the upland surface from the Iron Mask mine towards Shumway Lake. These erratics presumably came from Eagle H i l l near Copper Creek, a distance of twenty miles. " The author while studying the area prior to taking s o i l samples, observed five glacial erratic conglomerate blocks. Other glacial features such as an esker and moraine ridges damming a lake were recognized near Rossmore Lake which is about four miles from Lac Le Jeune. The glacial t i l l or d r i f t l a i d down by the moving ice was the parent material of the s o i l samples taken for study. This t i l l was light brownish gray in colour, compacted and coarse in texture. The portion passing through a 2 mm screen was classified as a sandy loam. However, the majority of the t i l l was made up of coarse, angular, par t i a l l y weathered fragments of greenstone, basalt, quartz diorite and grana-diorite• The geological formations had a pronounced effect on s o i l formation in the Lac Le Jeune area. In locations where the Kamloops basalt is the bedrock, soils formed from i t were brown in colour, shallow in depth and fine textured. Basalt normally contains l i t t l e or no free s i l i c a and upon complete weathering a relatively fine textured s o i l results. The high base content of basalt makes i t more susceptible to weathering than the acidic rocks such as granite. Soils derived from the coast intrusive granitic rocks were grayer in colour, shallower In depth and coarser in texture. Granitic rocks upon weathering release considerable amounts of free s i l i c a and thus give rise to coarse textured soils'. The glacial t i l l l aid down during the Pleistocene contained fragments of greenstone, basalt, grana-diorite, quartz diorite and gabbro. Appreciable amounts of rock flour or finely ground rock fragments were also found in the t i l l . The textures and colours of the soils formed on the glacial t i l l were between those of the soils developed from granite and basalt. The total depth of solum.was greater in the soils originating from 1'glacial t i l l than the soils developed 38 divided state of the glacial t i l l , which made i t relatively permeable to leaching, more profile development was evident in the soils derived from i t . Whereas the bedrock outcropp-ings of granite and basalt are relatively impermeable to leaching and thus the s o i l forming processes are i n i t i a l l y slow. Climate of the Lac Le Jeune Area, Specific climatic data for this area is unavailable. To provide approximate values of temperature and precipita-tion two climatic stations with somewhat similar conditions were chosen. Table 1 Climatic Data for Two Stations Near Lac Le Jeune Station Number of Years Location i n Respect to Lac Le Jeune Altitude Annual Annual Precipitation Temper (inche s) ature Mamette 34 15 miles 3200 11.97 o 37 P. Lake west Knouff 40 40 miles 3750 15.43 35°P. Lake north From observations and Interpretation of climatic data the average annual temperature for Lac Le Jeune would l i k e l y be between 35 - 36°F. and the annual precipitation would be in the range of 13 - 15 Inches. The estimations made by the Meteorological Division of the Department of Transport (145), closely approximate the above values. 3 9 Figure 1, Precipitation and Potential Evapotransplratlon Curves for Knouff Lake KEY: Precipitation Potential Evapo-tranapiration. Location and Soils of the Lao Le Jeune Area* Lac Le Jeune is situated twenty-two miles southwest of Kamloops i n the central interior of B.C» The lake is accessible by a class 2 highway© To reach most of the sampl-ing areas about the lake, advantage is t aken of the numerous f i r e guards which have been constructed as an aid i n forest f i r e control. The soils in the Lac Le Jeune area belong to the Brown Podzolic s o i l zone. A general description of these soils as taken from Spoils and Men (126), i s as follows: essentially the Brown Podzolic s o i l is an imperfectly developed Podzol having in timbered areas an organic mat on the surface and a very thin gray leached horizon just below i t — usually less than one inch thick. The B horizon is largely yellowish brown in colour and has only the beginnings of a dark brown orterde just below the gray A horizon. The total depth of the solum is usually less J F M A M J J A S 0 - N D J 4.5 4.0 W 3.5 U J A • / / / \ \ / / / \ \ N / / \ \ / / \ \ / / \ \ \ y \ \ 1 1 40 than 24 inches although i t exceeds that depth in places. The climate varies from temperate to cool temperate and humid, but the effective moisture averages less than i n the Podzols. Reactions of the s o i l are moderately to strongly acid and highly leached. According to Stobbe (129), morphological studies of a Brown Podzolic s o i l indicate that the profiles are more or less featureless and suggest a gradual decrease in the intensity of s o i l weathering with depth. He stated that under virgin conditions the Brown Podzolic soils have the following horizons: Ao - consists of a leaf mat 3/4 - 11/2 inches thick, in various stages of decomposition. The upper part i s fibrous and brown in colour, while the lower part is greasy and very dark grayish brown. A-i " the A© fades into the A^ horizon which on the aver-age varies from 1/2 to 2 inches in thickness but i t may occa-sionally reach a maximum of 3 l/2 Inches. In some cases the Al may be entirely lacking. The A^ is dark brown to dark grayish brown i n colour, very friable and has a weak fine crumb or fine granular structure. The organic matter is usually not as completely mineralized as in case of the Grey-Brown Podzolic and Brown Forest soils and frequently this horizon approaches a loose mechanical mixture of separate organic and mineral particles. Earthworms are not commonly found in this horizon.. The reaction is strongly to moder-ately acid. Ajj>- is generally lacking but i t may occur as a discontinuous 41 or interrupted horizon. If present i t occurs In the form of thin gray streaks, as occasional thicker or deeper pockets or as a somewhat indefinite grayish layer i n the lower part of the A i horizon. In the latter case i t con-sists of gray particles within the darker s o i l mass, giving a salt and pepper effect. The A2 i s usually single grained, somewhat lighter i n texture than the other horizons and i s strongly to moderately acide B - the change from the A2» %> o r &° horizon which ever the case may be, to the B horizon i s distinct and sharp. As a result the transitional B^ horizon is generally lacking. The total thickness of the B horizon varies greatly but on the average i t ranges from 29 to 30 inches. The upper part of the B i s brown, yellowish brown or reddish brown and the colour fades in intensity with depth u n t i l i t approaches that of the parent material in the lower part of the horizon. The upper part of the horizon, the B 2 i s very friable and has dominantly a fine crumb structure but; i t may also be weak granular or nuciform. In the lower part of the B^, the B 3, the s o i l con-sistence and structure are more variable depending on the nature of the parent material. Textural variations within the B horizons are not significant, nor consistent. The reaction varies from strongly to moderately acid, but i t is usually slightly higher in the B 3 than i n the upper part of the solum. G - the change f rom B 3 to C may be very gradual or i t may be, more or less, abrupt in the case of soils developed from compacted t i l l on sloping-topography. The parent materials 42 varied from t i l l to a l l u v i a l and outwash deposits and have been derived largely from granites, gneisses, schists, slates, and shales* Reaction of these materials i s generally moderately to mildly acid, but i t may occasionally be strongly acid. Description of Sampling Areas. This area i s the site of many past f i r e s * The present Forest Service f i r e map records f i r e s back to 1929. Ample evidence ia found of fires which destroyed extensive tracts of forest about the lake approximately eighty years ago. The soils sampled for study were taken i n areas which had been burned in 1943, 1945, 1945 and again i n 1951, and 1951* These three f i r e s took place within a period of three weeks i n late July and early August* Samples were also taken in unburnt areas adjacent to the burns* Much d i f f i c u l t y was encountered by the author in locating typical mature unburned Douglas f i r sites; however, two f a i r l y representative areas were located with mature trees between 350 and 400 years old. Similiar conditions of slope, exposure, drainage, top-ography and parent material were maintained throughout the s o i l sampling sites* The vegetation was nearly the same on a l l sites except for two burns. These exceptions were the f i r e of 1945 on a mixed stand of spruce, lodgepole pine and Douglas f i r , and the 1943 burn of mature Douglas f i r . On the remaining locations lodgepole pine was" the dominant tree cover type. In the 1943 burn of Douglas f i r tree cover, two pits were dug and samples taken according to horizon. Three pits were dug in the 1945 burn of lodgepole pine. In th© mixed stand of spruce, Douglas f i r and lodgepole pine which was burned in 1945 two pits were used for study* Investigations were carried out on two pits i n the stag-, nant lodgepole pine stand burned in 1951, Samples were taken from one p i t in the normal stand of lodgepole pine which was burned in 1951* Two pits were studied in.the area of lodgepole pine which had been burned over twice, once in 1945 and again in 1951, On the unburned 300*400 year old Douglas f i r site two profiles were studied© Three pits were used for sampling i n unburned 80 year old lodgepole pine stands* One pit was dug in the unburned 80 year old stagnant lodgepole pine area. In the unburned 80 year old stand of spruce, lodgepole pine, and Douglas f i r , one pit was studied* It should be explained that the number of pits studied depended upon how large the sampling area was* If the size of site was limited than the number of pits studied was reduced* The author f e l t that in these restricted areas the error due to sampling would be very materially reduced and thus the number of samples could be safely decreased, A profile description for each site is presented in Tables 3 to 11» In Instances where more than one profile is taken in an area only one w i l l be described unless there is a significant difference between the replicates. Ta ble 2: Profile Description of s o l i under Douglas f i r tree cover burned In 1943. Horizon Depth Texture Colour Dry Wet Structure Consistence Stones Roots Ao 1*" Humus 10 yr 4/1 Dark Gray 10 yr 3/1 Very Dark Gray . &2 Sandy Loam 10 yr 7/2 Light Gray 10 yr 3/4 Dark Brown Single Grained Slightly hard 20$ Some B 2 Sandy Loam 10 yr 7/3 Very pale Brown 10 yr 5/3 Brown Pine Qrumb Strong Slightly Hard 40$ Numerous B3 7 ^ 1 2 1 " Sandy Loam 10 yr 6/2 Light Brown ^ Gray 10 yr 4/2 Dark Gray Brown Pine Qrumb Weak Hard 50$ Many "6 12i«4 Clay Loam 10 yr 6/3 Pale Brown 10 yr 3/3 Dark Brown Massive Hard 60$ Pew Profile Development: Moderate Topography: 4260 feet elevation 2 percent southwest slope S o i l Drainage: subsoil drainage good Vegetation: Tree Cover: a l l original trees f i r e k i l l e d . ; 8 year old stand of lodgepole pine. Shrubs: willow, rose, alder, white hardback. Herbs: fireweed, lupine, twinflower, hawkweed, pine grass. Table 3: Profile description of s o i l under lodgepole pine burned In 1945. Horizon Depth Texture Colour Dry Wet Structure Consistence Stones Roots Ao r Humus 10 yr 2/2 Very Dark Brown 5 yr 2/1 Black < None AV Sandy Loam 10 yr 5/3 Brown 10 yr 3/3 Dark Brown Single Grained Soft None B2 Sandy Loam 10 yr 5/3 Brown 10 3/3 Dark Brown Pine Crumb (strong) Soft 30#- Many B3 10i"-16^ ^Loamy Sand 10 yr 6/2 Light Brown Gray 10 yr 4/2 Dark Gray Brown Pine Crumb (weak) Slightly Hard 40$ Pew C 16^ Loamy Sand 2.5 yr 7/2 Light Gray 10 yr 4/2 Dark Gray Brown Massive Hard 45$ Pew Profile Development: moderate Topography: 4290 feet elevation 1 percent southwest slope S o i l Drainage: subsoil drainage good yegetation: Tree cover: A H original trees f i r e k i l l e d ; five year old stand of lodgepole pine Shrubs: rose, sopolallie, willow, dwarf blueberry Herbs: pine grass Table 4s Profile description of s o i l under Douglas f i r , apruoe and lodgepole pine burned in 1945. ' '. Horizon Depth Texture Colour Dry Wet Structure Consistence Stones Roots Ao *» Humus io yr 2/2 Very Dark Brown 10 yr 2/1 Black None *2 C~i« Sandy Loam 10 yr 6/2 Light Brown Gray 10 yr 4/2 Dark Gray Brown Single Grained Slightly Hard 15$ None B 2 Sandy Loam 10 yr 6/3 Pale Brown 10 yr 4/3 Dark Brown Pine Crumb Strongly Slightly Hard 25$ Pew B3 Loamy Sand 10 yr 6/2 Light Brown Gray 10 yr 4/2 Dark Gray Brown Fine Crumb Weak Slightly Hard 45$ Some i3i w+ Loamy Sand 2.5y 7/2 Light Gray 2.4y 5/2 Gray Brown Massive Hard 50$ Pew Profile Developments moderate Topographys 4250 feet elevation 1 percent southeast slope S o i l Drainages subsoil drainage good Vegetations Tree Covers a l l original trees f i r e k i l l e d . 1 6'* - 12* high, spruce, lodgepole pine seedlings Shrub 3 s Canada dogwood Herbs: lupine, timber sedge, dandelion, flreweed Table 5: Profile description of s o i l under stagnant lodgepole pine burned In 1951. Horizon Depth Texture Colour Dry Wet Structure Consistence Stones Roots Ao Humus 10 yr 2/1 Black 10 yr Black 2/1 None A2 Sandy Loam 10 yr 6/2 Light Brown Gray 10 yr D ark Brown Gray 4/2 Thin Platy Medium Soft 10$ Pew B 2 f-6| n Sandy Loam 10 yr 6/3 Pale Brown 10 yr Dark Brown Gray 4/2 Pine Crumb St rongly Slightly Hard 25$ Many B3 6f~17ftt Glay Loam 10 yr 7/2 light Gray 10 yr Pale Brown 2/* Massive Hard 30$ Pew C 17f «> Glay Loam 10 yr 7/2 Light Gray 10 yr 6/2 Pale Brown Massive Very hard 35$ Pew Profile Development: moderate Topography: 4250 feet elevation slight southwest slope So i l Drainage: subsoil drainage f a i r yegetation: Tree Cover: a l l original trees f i r e k i l l e d "•'I HP' - 1 M high lodgepole pine seedlings ' Shrubs: r$se -Herbs: pine grass, fireweed, twinflower. 48 Table 6: Profile description of s o i l under lodgepole pine burned In 1951 Horizon Depth Texture Colour Dry Wet Structure Consistence Stones Hoots Ao 1* Humus 10 yr 2/1 Black 10 yr 2/1 Black Hone 42 Sandy Loam 10 yr 6/3 Pale Brown 10 yr 3/2 Very Dark Gray Brown Single Grained Soft 30$ Few B 2 Sandy Loam 10 yr 5/3 Pale Brown 10 yr 3/3 Dark Brown Fine Crumb (Moderate) Slightly Hard 40$ Many B3 a^isi" Loamy Sand 10 yr 6/3 Pale Brown 10 yr 4/2 Dark Gray Brown Fine Crumb (weak) Slightly Hard 45$ Some C 15i»* Loamy Sand 10 yr 6/3 Pale Brown 10 yr 4/2 Dark Gray Brown Massive Hard 55$ Few Profile Development: moderate Topography: 4270 feet elevation level S o i l Drainage: subsoil drainage good Vegetation: Tree Cover; a l l original trees k i l l e d small lodgepole pine seedlings Shrubs: * rose, white hardback Herbs: pine grass, lupine, fireweed CD Table 7: Profil e description of s o i l under lodgepole pine burned l a 1945 and again l a 1951* Horizon Depth Texture Colour Dry Wet Structure Consistence Rocks Roots Ao Humus 7,5 yr 4/2 Dark Brovn 10 yr 2/2 Very Dark Brown Hone A 2 Sandy Loam 10 yr Light Brown Gray 6/2 10 yr Dark Brown 3/3 Single Grained Loose 20$ Few B 2 Sandy Loam 10 yr Pale Brown 6/3 10 yr Dark Brown 4/3 Pine Crumb Moderate Soft 35$ Some B 3 7i*13i* Loamy Sand 10 yr Light Brown Gray 6/2 10 yr Dark Gray Brown 4/2 Pine Crumb Weak Slightly Hard 48$ Some C I 3 i w * Loamy Sand 2.5y 7/2 Light Gray 10 yr Dark Gray Brown 4/2 Massive Hard 54$ Few Profile Development, moderate S o i l Drainage: Vegetation: subsoil drainage good Topography: 4200 feet elevation 3 percent southwest slope Tree Cover: a i l original trees were f i r e k i l l e d l n high lodgepole pine and aspen seedlings Shrubs: alder, willow Herbs: fireweed, dandelion, twinflower, goatsbeard, timber sedge, strawberry Table 8: Profile description of s o i l under 300*400 year old Douglas f i r . 50 Horizon Depth Texture Colour Dry Wet Structure Consistence Rocks Roots A© lf» Humus 10 yr Dark Gray Brown 4/2 10 yr 2/1 Black Many A 2 Of" Sandy Loam 10 yr Light Brown Gray 6/2 10 yr 4/2 Dark Gray Brown Single Grained Slightly Hard 15$ Many B 2 f~7f» Sandy Loam 10 yr Light Brown Gray 6/2 10 yr 4/2 Dark Gray Brown Pine Crumb Strong Slightly Hard 40$ Numert B 3 7f«17f« Sandy Loam 10 yr Light Brown Gray 6/2 10 yr 4/2 Dark Gray Brown Pine Crumb Weak Slightly Hard 45$ Many C 17f«* Loamy Sand 10 yr Light Gray 7/2 2.5y 5/2 Gray Brown Massive Hard 55$ Pew Profile Development: Moderate Topography: 4290 feet elevation 3 percent southerly slope S o i l Drainage: subsoil drainage good Vegetation: Tree cover: Douglas f i r dominant, some lodgepole pine Shrubs: sopolailie, willow, dwarf blueberry, klnniklnnick Herbs: pine grass, strawberry, twinberry, lupine, timber milk vetch, timber sedge, yarrow, arnica o 51 Table 9: Profile description of s o i l under 80 year old unburned lodgepole pine. Horizon Depth Texture Colour Structure Consistence Bocks Hoots Dry Wet Ao Humus 7.5yr 3/2 Dark Brown 5 yr 3/3 Dark Reddish Brown Many 42 Sandy Loam 1© yr 6/2 Light Brown Gray 10 yr 4/2 Dark Gray Brown Single Grained Slightly Hard 15$ Some B 2 Sandy Loam lO yr 6/3 Pale Brown 10 yr 4/3 Brown to Dark Brown Pine Crumb Strong Slightly Hard 35$ numerous B3 7a-15i Sandy Loam 2.5y 7/2 Light Gray 10 yr 4/2 Dark Gray Brown Fine Crumb Weak Soft 45$ Many G 1§1^** Loamy Sand 2.5y 6/2 Light Brown Gray 10 yr 4/2 Dark Gray Brown MassITS Hard 50$ Pew Profile Development: moderate Topography: 4290 feet elevation nearly level S o i l Drainage: subsoil drainage good yegetation: Tree Cover: lodgepole pine dominant, willow Shrubs: rose, dwarf blueberry, red alpine blueberry, kinnickinnick, white hardback, alder. Herbs: pine grass, lupine, fireweed, twinfiower, timber milk vetch, hawkweed, strawberry. Oi 52 Table 10; Profile description of s o i l under 7 0 - 8 0 year old, unburned, stagnant Horizon Depth Texture Colour Dry Vet Structure Consistence Rocks Roots Ao 2» Humus 10 yr 4/1 Dark Gray 1© yr 3/1 Very Dark Gray Many 42 o~f« Sandy Loam 10 yr 6/2 Light Brown Gray 10 yr 4/2 Dark Gray Brown Thin Platy Strong Soft 10$ Some Bg f-7f« Loam 10 yr 6/2 Light Brown Gray 10 yr 4/2 Dark Gray Brown Fine Crumb Strong Slightly Hard 25$ Humeri B3 7f*14f* Glay Loam 10 yr 7/2 Light Gray 10 yr §/2 Gray Brown Massive Hard 30$ Few C 14f»* Glay Loam 10 yr 6/2 Light Brown Gray 10 yr 4/2 Dark Gray Brown Massive Very Hard 35$ Few Pr o f i l e Development: moderate Topography: 4250 feet elevation f l a t S o i l Drainage: subsoil drainage f a i r Vegetation: Tree Cover: stagnant lodgepole pine Shrubs: dwarf blueberry, rose, kinniklnnick Herbs; pine grass dominant, twinflower, strawberry, fireweed, wlntergreen. Table l i t Profile description of s o i l under 70"80 year old, unburned, mixed stand " of lodgepole pine, Douglas f i r and spruce. ' Horizon Depth Texture Colour Structure Consistence Rocks Roots Dry Wet Ao 2" Humus 10 yr 4/4 Dark Brown Yellowish iO yr 3/4 Dark Brown Pew &2 Sandy Loam 10 yr 7/2 Light Gray 10 yr 5/3 Brown Single Grained Slightly Hard 15$ Pew B2 Sandy Loam iO yr 7/3 Very Pale Brown 10 yr 5/3 Brown Pine Crumb Strongly Slightly Hard 25$ Numerous B 3 8^12^ Sandy Loam 1 10 yr 7/3 Very Pale Brown 10 yr 5/3 Brown Pine" Qrumb Weak Slightly Hard 45$' Some C 12#»+ Loamy Sand lO yr 6/3 Pale Brown 10 yr 4/2 Dark Gray Brown Massive Hard ' 50$- Pew Profile Development: moderate Topography: 4250 feet elevation • . . . . 3 percent southeast slope S o i l Drainage: subsoil drainage good Vegetation: Tree Cover: lodgepole pine, Douglas f i r , spruce ; Shrubs: Herbs: twinf lower Ol 54 Morphological Features* The organic horizon of the unburned soils is an incompletely decomposed mor type (56). In a l l proflies studied the F or ferm-entation layer is dominant while the H or humified layer and the L or l i t t e r layer seldom attain measurable thickness. In studying the ash grey leached layer considerable varia-b i l i t y i s encountered. There i s such a horizon i n a l l the pro-f i l e s sampled for chemical study. However, i t is possible i n 3 o m e instances to move fi f t e e n feet from a profile with an A 2 and find a profile with this horizon lacking* In other cases a short distance away from a studied s o i l sampling site lk inch thick A 2 horizons are found* Under f i e l d conditions the leached layers are somewhat lighter than indicated by the colour des-criptions. Although considerable care was exercised in sampl-ing, small portions of organic material and Bg were included in the samples because of the d i f f i c u l t y in sampling such a shallow horizon* In some areas the A 2 i s somewhat compacted and has a definite platy structure* As a rule the A 2 i s slightly compacted and structureless* The next horizon, the Bj>, represents a sharp and distinct break between the A horizons and the B horizons. In the Lac Le Jeune area there is not any evidence of a transitory horizon. The B 2 horizon of a l l profiles studied i s a pale brown to a light brown gray in colour* This horizon tends to be a pale brown under lodgepole pine and unburned Douglas f i r the colour i s usually a light brown gray. In a l l the profiles studied the texture of the B 2 is a sandy loam. Usually the Bg is friable 55 and has a fine crumb structure. Burning tends to alter the structure in the top two inches of the B 2. The burned upper portion of the B 2 becomes massive while the lower portion retains i t s crumb structure* The B 3 horizons of a l l the profiles were a light gray or a light brown gray in colour. It is less aggregated than the Bg' and has a weak crumb structure. This horizon i s not as friable as the B 2 as i t tends to be more compacted and massive. A light gray glacial t i l l is the parent material or C horizon of a i l the profiles studied. The t i l l i s compacted and remained relatively unweathered. In the C horizon the following sub-angular rocks occurs granite, basalt, green-stone, and gabbro. Free lime accumulations are not observed in the C horizon. In a l l the profiles studied drainage is unimpaired except for the relatively impervious C horizon. 56 METHODS OF ANALYSIS A* Physical Properties. Determination of S o i l Texture:- A H samples were passed through a 2 mm sieve preparatory to analysis. The proportion of r o c k 3 and fine material was determined at each s i t e . Each s o i l sample was textured by hand. As a check on the accuracy of this method two profiles were selected and mechanical analyses were carried out on the fine s o i l fraction by the Bouyoucoa method (13). The values obtained using Bouyoucosfs procedure were interpreted by means of the textural triangle (140). A comparison of the two methods is found in Table 12. Determination of Non-capillary porosity, Capillary porosity and porosity:- S o i l cores to a 3 inch depth were taken in dup-licate from beneath each of the 10 varying vegetative covers* Non-capillary poro3ity was determined on a tension table after the method of Learner and Shaw (83). Capillary porosity was measured by weighing the core when a l l ' the non-capillary moisture had been extracted and then weighing the core after i t had been oven-dried. The difference in weight between the two weighings represents capillary porosity. The percent por-osity was found by determining the weight of the f u l l y saturated core and subtracting from this value, the oven-dry weight of the core. This value represents pore volume. By dividing the pore volume of the brass core, the percent porosity can be obtained. Determination of Volume Weight:- The brass cylinders used for taking cores have a known and approximately equal volume. Volume weight i s found by dividing the nearly constant volume 57 into the oven-dry weight of the a o i l core. Determination of Infi l t r a t i o n Rates:- The procedure followed was that of Burn3 (18). Water Infiltr a t i o n measure-ments were made in the f i e l d with two replicates being carried out at each s i t e . After the unincorporated organic debris was removed from the s o i l surface a steel cylinder, 20 cm. high, having cross-sectional area of 100 square centimeters, was driven into the s o i l to a depth of 10 cm. A piece of muslin placed on the s o i l surface Inside the cylinder prevented dis-turbance of the soi l particles. One l i t e r of water was added, and the time required for i t to pass into the s o i l was recorded. Determination of S o i l Temperature:- A Weston s o i l ther-mometer was used to take six replicate readings at a depth of 3 inches. These values were obtained for the s o i l beneath each of the 10 varying vegetative covers. B. Chemical Properties. Determination of pH:- D i s t i l l e d water was added to the dry sieved s o i l and thoroughly mixed u n t i l a s o i l paste was obtain-ed as recommended by The National S o i l Survey Committee (134)} The prepared s o i l paste was allowed to slake for twenty minutes and then the pH readings were determined using a Beckman pot-entiometer. Determination of Organic Matter:- The organic matter determinations were carried out by the wet combustion procedure as outlined by Peech et a l . (106). One major modification was the use of the more stable ferrous ammonium sulphate in the place of ferrous sulphate* Determination of Total Nitrogens- Total nitrogen was determined by the modified Kjeldhal method (6). Determination of Total Phosphorouss- For the measurement of total phosphorous the perchloric acid method outlined by Shelton and Harper (123), was used. Determination of Carbonic Acid Soluble Plant Nutrients:-The method used for extracting the plant nutrients was a mod-if i c a t i o n of the COg extraction procedure used by Wilcox (147), and the system recommended by the National S o i l and F e r t i l i z e r Research Committee (133). Details of the procedure used is as f. <•< p ,i ' ' follows: ' (a) A unit consisting of two sets of six 500 c.c. erlenmeyer flasks f i t t e d with two hole stoppers and the appro-priate glass tubing was attached in series to a tank of liquid COg. As a result of the arrangement in series, the contents of egieh flask was thoroughly and constantly agitated. (b) Mineral so i l s were mixed with d i s t i l l e d water in the ratio of 1:2 or in the case of organic soils and Ao horizons a ratio of 1:12 was used. (c) Activated carbon was added to each s o i l and dis-t i l l e d water'mixture• Peech and English (105), advocated In their procedure of extracting readily soluble (minerals the use of 1/4 gram of activated carbon for each 10 grams of mineral s o i l and the use of l/2 gram of carbon for each 10 grams of organic s o i l used. It was found necessary to add carbon to ensure that the f i l t r a t e s be colourless for colourimetric analysis. (d) COg was passed through the mixtures in a steady 59 stream at the rate of approximately 60 c.c. per minute for one hour. Each flask was manually shaken at ten minute intervals. ' (e) The whole was f i l t e r e d by suction through Whatman No. 5 f i l t e r paper immediately after the one hour treatment with C0 2. The method used for determining carbonic acid soluble phosphorous, potassium and calcium was essentially that outlined by Wilcox (146). Carbonic acid soluble magnesium and nitrate were found by approximately the same methods as used by Peech and English (105)* Minor deviations from the above procedures were necessary in order to adopt them for use with the Hilger biochemabsorptiometer• Determination of Exchange Capacity and Exchangeable Bases The normal ammonium acetate method as described by Schollenberger and Simon (119), was used to determine the exchange capacity and exchangeable bases. It was decided that two profiles should be so studied to see i f there was any striking change. The two profiles selected represented the two most extreme cases in the study, one was an unburned lodgepole pine site and the other profile selected was the lodgepole pine severely burned i n 1945 and burned again in 19510 60 RESULTS AND DISCUSSION Texture was relatively uniform throughout a l l the soils studied* Since texture was determined to aid in classification only, no relationship between texture and burning, i f any, was sought. The comparison between Bouyoucos's method of mechanical analysis and hand texturing indicates that hand texturing ia sufficiently accurate for the purpose in mind. In the majority of the sites sampled, the percent porosity decreased with burning. With repeated burning illustrated by the bums of 1945 and 1951 a substantial reduction in percent porosity occurs. The decrease was from 68*25 to 52*50 percent porosity. On the other hand an increase in porosity was ob-served in the 1943 burn of Douglas F i r tree cover. This may be a result of the beneficial action on s o i l structure of the grasses which became more abundant after burning. An explana-tion for the increase i n porosity in the stagnant lodgepole pine burn of 1951 might be the addition of considerable amounts of foliage from the dead trees. Such an addition to the Ao may have resulted in a greater depth of porous Ao. In the remainder of the samples burning decreased porosity. This reduction i n porosity is probably due to destruction of the very porous organic mat resulting in exposure of s o i l to the elements and the break-down of the fine crumb structure by f i r e . A further reduction in porosity results from clogging of s o i l pores by suspended material. Burning produced a substantial increase i n the percentage of capillary pore space i n a i l the cores studied* Such an increase is partially explained by the reduction of porous l i t t e r , 61 the destruction of s o i l aggregates and the consequent washing in and plugging of the larger s o i l pores with ash. The alka-line ash may cause dispersion of s o i l particles which may in turn he carried into the s o i l pores f i n a l l y f i l l i n g J»he larger voids. With removal of the Ao the top 0-3 inches of s o i l w i l l normally include more mineral s o i l which has finer pores than the relatively open organic horizon. ' As a result of f i r e the amount of non-capillary porosity was reduced in a l l the samples. The removal by f i r e of the porous Ao which contains many large pores w i l l thusb ring about a marked reduction in the percentage of non-capillary porosity. In the burn of 1945 and again in 1951 the non-capillary porosity was reduced the most, from 22.08 percent in the unburned area adjacent to the burn, to 9.85 percent in the burned s i t e . The data indicated that burning brought about an increase in volume weight of the 0-3 inch layer. A H the cores invest-igated showed substantial increases in volume weight. The greatest increase was from .390 for the unburned mixed stand of lodgepole pine, spruce, and Douglas f i r to .990 for the corresponding area burned in 1945. These increases are the result of compaction bf the surface s o i l by rain and the inclusion of more of the dense mineral s o i l i n the 0-3 inch layer. Burning greatly altered the rate of i n f i l t r a t i o n on a i l the sites studied. The greatest reduction occurred in the 1943 Fir e . In the 1951 Fire l i t t l e or no effect was observed. Apparently more than two years are necessary to affect i n f i l t r a t i o n rates. 4s the time required for entry of water increased with the age of the f i r e , i t would appear that the length of exposure to the elements i s the controlling factor In decreasing i n f i l t r a t i o n rates. Exposure of the hare sur-face s o i l results in compaction and destruction of s o i l struc-ture whieh greatly affects i n f i l t r a t i o n rates. S o i l temperature at a 3 inch depth indicated that burned over soils were warmer. The warmest s o i l was the area burned in 1945 and 1951, The value obtained for this area was 70°P. as compared to 54°P; for a comparable unburned location, 4 p p a r e n t l y with the removal of the Ao and with the f a l l i n g of the dead trees the s o i l has lost i t s insulating agents and the ground is subject to more rapid changes in and greater extremes of temperature. The 1951 burn of lodgepole pine and stagnant lodgepole pine did not result in as large a change in temperature as did the older burns. Much charcoal was observ-ed on the s o i l surface i n the 1951 f i r e s but the shade of the s t i l l standing dead trees probably reduced the amount of radiation reaching the charcoal. A H the recent burns brought about positive increases i n the pH of the 40• The greatest increase In pH occurred i n the 1945 and 1951 burn. The pH values rose from pH 4.5 to pH 745 in the Ao of these samples. Increases in the A2 were observed in several of the samples. One Increase was recorded i n the lodgepole pine burn of 1945 where the. pH rose from 4.65 to 5.3. Another rise in pH of the A2 was found In the burn of 1945 and 1951 where the pH rose from 4.92 to 6.03. No changes in pH of the A 2 occurred in the burn of 1951. It would thus appear that several years precipitation is essential to carry down the minerals before the pH of the Ag rises. With two burns the Ao is so reduced that the ash becomes partially incorporated with the Ag and thus a rise i n pH i s registered. With the change in vegetation from Douglas f i r to either lodgepole pine or a mixed stand of lodgepole pine, Douglas f i r and spruce a substantial decrease in pH of the Ao and Ag was found. Lodgepole pine foliage is more acidic than that of Douglas f i r (131), and i t could possibly bring about a reduc-tion i n pH by increasing the intensity of leaching of the s o i l minerals. The values obtained indicate that the pH of the burned soils w i l l decrease 3 to 4 years after the f i r e . Analysis of the various profiles indicate that burning decreases the percent organic matter in the remaining duff but did not bring about any change below the Ao. It is ob-served that in a l l samples a great reduction in the percent organic matter of the Ao occurred with burning* An example of the effect of f i r e is the reduction from 26 percent organic matter in the Ao to 5 percent organic matter in the Ao of the lodgepole pine sites burned in 1945 and 1951. Since no marked changes were found below the Ao, i t appears thai the f i r e temp-eratures i n this area were not sufficiently warm to destroy in-corporated organic matter. Burning had l i t t l e or no effect on total nitrogen below the Ag. In the Ao and Ag horizons there are decreases and increases in the total nitrogen content. Total nitrogen decreased in the Ao of the mixed stand of lodgepole pine, sprue© and Douglas f i r which was burned in 1945. In the Ag of the same burned soils the total nitrogen content Increased. Such an increase may be the result of increased bacterial activity after the fir© or i t may be due to the removal of the more soluble nitrogenous salts to the lower horizons. Total nitrogen content is lowered in the Ao of the Douglas f i r area burned over in 1943. There i s no change in the A 2. an increase of #03 percent is observed in the B 2 horizons which i s probably a result of stimulated bacterial activity and leaching. In the Ao of the lodgepole pine burned in 1945 and 1951 decreases of up to 80 percent were recorded. Losses of total nitrogen occurred in the Ao of the soil under lodgepole pine which was burned in 1945. The effect on the A 2 of the s o i l i n the same burn varied. Ih one pit a decrease in total nitrogen i n the Ag resulted whiie in another sampling area an increase i n the 4g was found. A reduction in both the Ao and A 2 occurred in the lodgepole pine burn of 1951. Increases in total nitrogen were found in the Ao of the stagnant lodgepole pine burned in 1951. Burning was responsible for an increase in total phosphor-ous in the Ao of most of the soils studied. The Ao horizon of the Douglas f i r area burned in 1943 had a decrease in phosphor-ous. A decrease in total phosphorous of the Ao horizon was found in the soils under a mixed stand of lodgepole pine, Dougla f i r and spruce which had been burned in 1945. An explanation fo the decrease i n total phosphorous for these burns might be the loss of phosphorous i n the smoke as described by Isaac and Hopkins (73), or i t could be a result of the wind blowing the ash and top s o i l as recorded by Pechanec and Stewart (104). 4 trend indicating that burning of lodgepole pine in 1945 only and in 1945 and again in 1951 resulted i n an increase of total phosphorous of the Ag* Rainfall probably carried some of the soluble phosphorous down to these lower horizons. With the ex-ception of the example mentioned the results below the Ao varied to such an extent that no conclusion could be made as to the effect of f i r e on the total phosphorous content in the subsoil. The carbonic acid soluble phosphorous content of the Ao horizon was greatly reduced as a result of burning. The only sample not demonstrating such an effect was one site in the 1951 burn of stagnant lodgepole pine. The reason for no decrease in the availability of phosphorous at this site may have been due to the absence of excessive amounts of calcium. According to Thome and Peterson (135), CaO induced alkalinity w i l l greatly reduce the availability of phosphorous. Teakle (132), demonstrated that phosphate concentration i n the s o i l solution was greatly reduced as pH values rose from 4.5 to 6.5. A H the samples studied except one site i n the 1945 and 1951 burn of lodgepole pine and one site i n the 1951 burn of stagnant lodgepole pine showed a decrease i n avai l a b i l i t y of phosphorous in the Ag. The effect of f i r e varied in the Bg. The availability of phosphorous decreased i n the Bg of the Douglas f i r burn in 1943, the lodgepole pine burn of 1945, the 1951 burn of lodgepole pine and the stagnant lodgepole. pine burn of 1951. No change in the availability of phosphorous in the Bg was observed in the remaining samples. The age of the burn appeared to have some 66 effect on the degree of change in availability of phosphor-ous in the Ao horizons. Recent burns did not appear to have as much effect on availability as the older burns. Possibly several years must pass before a l l the released calcium in the ash can react with the released phosphorous. A comparison of carbonic acid soluble phosphate and total phosphorous reveals that in the Ao of the unburned s o i l approximately 25 percent of the total phosphorous is available while in the burned Ao horizons very l i t t l e of the total phosphorous is available. Similiarly Bujakowsky (17), observed that the normal organic horizon contained 20 times as much soluble phosphorous as, did the mineral s o i l . Burning thus appears to decrease the portion of total phosphorous which i s available. GOg available potassium decreased in the Ab of a i l but • one sample studied. The Ao of one sample of the stagnant lodgepole pine burned in 1951 did not have a decrease. The data indicates that the potassium released in the ash must be readily soluble and easily leached. Increases in potassium content of the Ag did not follow a given trend. Eight of the samples studied showed a decrease in CO^ soluble potass-ium. The remaining four samples had an increase in potassium. Increased leaching following the removal of vegetation by the f i r e , apparently removed most of the potassium beyond the Ag. In the Bg horizons the potassium content increased in a l l but two samples. Although the B3 horizons were not studied, i t is possible that the potassium In the two excep-tions had been leached to greater depths. The accumulation 67 of potassium in the subsoil after a burn i s in agreement with work done by Ride out (112). An increase in the content of COg soluble calcium in the Ao horizons of recently burned soils ma found. Decreases in the amount of calcium in the Ao of the bums i n 1943 and 1945 occurred. The largest decrease was recorded in the 1943 burn while but a slight decrease was observed i n the 1945 burns. It appears that after 8 or 9 years a l l the added calcium i s leached to lower horizons or i s u t i l i z e d by the new ground cover. The values obtained for the Ag varied considerably. Five of the samples showed an increase in calcium content while the remaining seven samples showed decreases. In the more recent burns as in 1951 the calcium content in the Bg horizons did not change to any extent. In the burns of 1943, 1945, 1945 and 1951 increases in four of the samples and decreases in the remaining five samples were found. The samples indicating an increase in the Bg were probably receiving calcium which had been leached from the Ao and Ag horizons. Decreases i n the calcium content of the Bg may have resulted from increased leaching due to the re-moval of ground cover by f i r e . COg soluble magnesium showed some var i a b i l i t y i n the Ag and Bg. There was a trend to an increase in magnesium of the Ao horizon in the recent burns of 1945 and 1951 and 1951. The content of magnesium decreased in the Ao of the older burns in 1943 and 1945. Excessive leaching probably removed the added magnesium to the subsoil. The values for C0 2 soluble nitrates showed a decrease 68 i n the Ao of the burned s o i l s . In the Ag horizon the results were varied. Prom the data i t is indicated that eight out of the twelve burned s o i l samples showed an increase of nitrates in the Bg horizon. Possibly after the burn ni t r i f i c a t i o n was was stimulated at the s o i l surface but with considerable leach-ing the nitrate was carried to the subsoil. The comparison between the twice burned profile 1945 and 1951 and the adjacent unburned profile indicated that there was some reduction in the base exchange capacity i n the Ao• No substantial change was observed below the Ao. Exchange-able calcium was greatly increased i n the Ao and slightly increased in the Ag of the burned s o i l . The content of exchangeable magnesium rose in the Ao, A2>&ud Bg of the burned s o i l . Increases In exchangeable potassium were found in the Ao, Ag> and B 2, and B 3 of the burned p r o f i l e . According to the data the percent base saturation Increased in the Ao, A 2» Bg» a n < i % °f the burned s i t e . 69 CONCLUSIONS 4s a result of forest fi r e s the following changes occurred in the s o i l of the lodgepole pine, Douglas f i r and the mixed stands of lodgepole pine, Douglas f i r and spruce forests near Lac Le Jeune. (1) 4 reduction in percent porosity of the top 0-3 inches 6f s o i l due to the destruction of both the porous organic horizon and the crumb structure of the upper portion of the Bg horizon. 4 further reduction was the result of the s o i l pores being clogged by ash and sus-pended s o i l particles. (2) Increased percentage of capillary pore space of the 0-3 inch layer because of the destruction of the Ao horizon and the compaction of the exposed s o i l by r a i n . (3) 4 decrease in the percentage of non-capiila ry pore space or air volume in the 0-3 inch layer resulting from the destiructioh of the Ao with Its large pores. The compacting effect of rain drops on the erumb structure of the Bg horizon also aided in decreasing the non-capillary porosity. (4) An increase in volume weight of the 0-3 inch layer due to compaction and destruction of the less dense Ao. (5) A decrease in the i n f i l t r a t i o n rate due to compaction and destruction of s o i l structure. (6) An increase i n s o i l temperature at a depth of 3 inches resulting from the addition of charcoal which absorbs heat and the destruction of vegetation and forest l i t t e r which norma l l y serve as insulating agents. (7) . 4n increase in pH of the Ao and i n some cases of the Ag as a result of the release of basic minerals from the ash. There was an indication that the basic minerals may be leached downwards to the A2» The pH of the Ao decreased 3 or 4 years after the f i r e . (8) A decrease i n the organic matter content of the duff which had not been totally destroyed by f i r e . Below the Ao no change occurred. (9) A decrease in the total nitrogen content of the Ao due to the volatilization of nitrogen during the f i r e . No definite trend could be established below the Ao. (10) An increase in total phosphorous in the Ao because of the release of this element from the l i t t e r . (11) A reduction i n the carbonic acid soluble phosphorou in the Ao due to i t s combination with the excess calcium to form an Insoluble compound* Slmillarly a decrease in COg soluble phosphorous occurred in the A.2* (12) A decrease in COg soluble potassium In the Ao and Ag resulting from unrestricted leaching* An increase in COg soluble potassium i n the Bg horizon. (13) An increase in COg soluble calcium i n the Ao of recent burns due to the presence of large amounts of calcium in the ash. Apparently 8 or 9 years are required before a l l the added calcium is either leached to lower horizons or u t i l i z e d by succeeding vegetation. (14) An increase in COg soluble magnesium in the Ao of the recent'burnso The content decreased i n the A© of the older burns because of increased leaching. (15) 4 decrease In COg soluble nitrates in the Ao, An increase in nitrates in the B g is probably a result of i n -creased n i t r i f i c a t i o n at the s o i l surface followed by con-siderable leaching* (16) A reduction i n the base exchange capacity of the Ao* An increase in exchangeable calcium in the Ao and Ag* An increase in exchangeable magnesium in the Ao, A g and B g horizons* An Increase in exchangeable potassium i n the Ao, Ag» Bg, and B^* An increase in percent base saturation in the A©, Ao# Bp, and B , levels* APPENDIX Popular Name Trees: Aspen Douglas f i r Lodgepole pine Spruce Shrubs: Alder Canada dogwood Dwarf blueberry Kinnickinnick Red alpine blueberry Rose Sopolallie White hardback Willow Herbs: Arnica Dandelion FIreweed Goatsbeard Hawkweed Lupine Pine grass Strawberry Timber sedge Tliober milk vetch Twin flower Wintergreen Yarrow Scientific Name Populus tremuloides Pseudotsuga t a x i f o l i a Pinus contorta Picea engelmannl Alnus sitchensis Gornus canadensis Vaccinium caespitosum Arctostaphylos uva-ursi Vaccinium scoparius Rosa spp Eleagnus canadensis Spiraea luclda Salix barclayii Arnica cordifolia Taraxacum officinale Epilobium angustlfollum Tragopogon pratensls Hieracium a lb i f lo rum Lupinus articus Calamagrostis rubescens Fragaria glauca Caren conncinoides Astragalus serotinus Linnaea borealis Pyrola secunda Achillea millefolium Table 12; COMPARISON OF THE RESULTS OBTAINED BY THE BOUYOUCOS METHOD OF MECHANICAL ANALYSIS AND HAND TEXTURING. Map Site Description Method Horizon Number A2 B^ 8 1945 Burn of Bouyoucos Sandy Sandy Loamy Loamy Lodgepole Loam Loam Sand Sand Pine Hand Textur- Sandy Sandy Loamy Loamy ing Loam Loam Sand Sand 9 Unburned Bouyoucos Sandy Sandy Loamy Loamy Lodgepole ; Loam Loam Sand Sand . Pine . Hand Textur- Sandy Sandy Sandy Loamy ing Loam Loam Loam Sand TABLE 13: THE EFFECT OF FIRE ON THE NON-CAPILLARY POROSITY , CAPILLARY POROSITY, PERCENT POROSITY AND VOLUME-WEIGHT OF THE SOIL MAP SITE NUMBER. DESCRIPTION NON-CAPILLARY POROSITY AVERAGE CAPILLARY POROSITY AVERAGE PERCENT POROSITY AVERAGE VOLUME WEIGHT AVERAGE 1 1943 Bum of Douglas f i r 22.75 27 .93 25.34 45.45 36.67 41.06 68.40 65.00 66.70 •680 .712 • 696 3 Douglas f i r Unburned 32.13 34.13 33 .13 30.37 31.75 31.06 62.70 66.20 64 .40 .543 .523 •535 5 1945 Burn of Mixed Stand 12.60 16.01 14.30 46.95 40.81 43.88 59.80 56.70 58.25 .985 .996 .990 7 Unburned Mixed Stand 29.24 40.15 34.69 32.94 30.09 31.51 59.30 70.40 64.85 .573 .357 .465 8 1945 Bum of Lodgepole pine 22.28 22.82 22.55 42 .47 36.39 39.43 65.00 59.40 62.20! • 1 •620 •680 .654 9 Unburned Lodgepole pine 29.12 36.58 32 .85 30.15 34.76 32.45 59.00 71850 i 65.25 •541 •445 .493 10 1945 Bum of Lodgepole pine 17 .02 15.64 16.33 40.87 40.00 40.43 57.40 55.80 56.60 0889 .821 .855 12 Unburned Lodgepole pine 19.59 24.57 22.08 39.18 32.63 36.40 69.00 67.50 68.25 •735 1 .563 •649 # 14 1945 and 1951 Burn of Lodgepole Pine 9.01 10.69 9.85 , 42.12 42.90 42.51 51.20 53.80 52.50 ' 1.050 1.223 1.136 # 15 1951 Bum of Lodgepole pine 19.47 . 32.44 25.95 42.39 38.06 40.47 63.60 70.50 67105 .967 .704 •835 18 1951 Burn of Stagnant Lodgepole pine 36.38 35.51 35.94 43.77 34.01 33.89 74.50 69.50 72.00 .774 •493 •633 19 Unburned Stagnant Lodgepole pine 29.71 35.92 32.81 41.88 34.13 38.00 71.80 70.20 71.00 •424 .356 .390 # COMPARE WITH MAP SITE 12. TABLE 14 THE EFFECT OF FIRE ON THE RATE OP WATER INFILTRATION " AID SOIL MrERAfUHE MAP SITE RATE OF NUMBER DESCRIPTION INFILTRATION MINUTES AVERAGE IN MINUTES SOIL TEMPERATURE AT A DEPTH OF 3 INCHES 1 1943 Burn of Douglas f i r 118 105 111 64 °F 3 Unburned Douglas f i r 29 36 32 58°F 5 1945 Bum of Mixed Stand 60 72 66 66°F 7 Unburned Mixed Stand 24 18 21 55°F 3 1945 Bum of Lodgepole Pine 24 23 23 620F 9 Unburned Lodgepole pine 19 14 16 53°F 10 1945 Burn of Lodgepole pine . 45 31 38 59°F 12 Unburned Lodgepole pine 13 18 15 54^F 14 1945 and 1951 Burn of Lodgepole pine 112 60 86 70° F. 15 1951 Burn of Lodgepole pine 17 18 17 63°F. 18 1951 Bum of Stagnant Lodgepole pine 42 31 36 58°F. 19 Unburned Stagnant Lodgepole pine 18 12 15 52°F. # Compare with Map Site 12 76 TABLE 15 THE EFFECT OF FIRE ON SOIL pH Map S H E NUMBER DESCRIPTION Ao AVERAGE A2 AVERAGE B2 AVERAGE B3 AVERAGE C AVERAGE 1 2 1943 Burn of Douglas f i r 5,80 5.60 5.70 5.60 5.20 5.40 5.80 5.70 5.75 6.20 6.00 6.10 6.45 6.20 6.32 3 4 Unburned Douglas f i r 5*80 5.35 5.57 5*90 5.40 5.65 5*95 5*82 5.88 6*20 6.05 6 .12 5.90 6.02 5.96 5 6 1945 Burn of [ Mixed Stand 5.46 5.15 5.30 4.88 5.10 4 . 99 5.55 6.08 5.81 5*92 6.45 6*28 6.2 6*4 6*30 7 Unburned Mixed Stand 4.80 4.80 4.75 4.75 5 .62 5*62 5.9 5.9 6.65 6*65 a 1945 Burn of Lodgepole Pine 5.20 5.20 5.3 5.3 5.95 5.95 6.15 6.15 6.45 6*45 9 Unburned Lodgepole Pine 4.70 4.70 4.65 4*65 5.30 5.30 5.46 5.46 5 .45 5.45 10 11 1945 Bum of . Lodgepole Pine 5.80 5.50 5.65 5.40 5*42 5.41 6.15 5.8 5.97 6*25 6.15 6.20 6.32 6.25 6*28 12 Unburned Lodgepole Pine 4.50 4.50 4.92 4.92 5.45 5*45 5.95 5.95 6.25 6.25 # 14 1945 & 1951 Burn of Lodgepole Pine 7.70 7.18 7.44 6.30 5.76 6.03 5.82 6.00 5.91 6.30 6.05 6.17 6.35 6*55 6.45 15 1951 Burn of Lodgepole Pine 6.65 6.65 5.45 5*45 6.29 6*29 6.10 6.10 5.90 5.90 16 Unburned Lodgepole Pine 5.05 5.05 5.62 5.62 6.10 6.10 6.32 6.32 6.60 6.60 17 18 1951 Burn Stagnant Lodgepole Pine 6.22 6.25 6.23 b.10 5.35 5*22 b.60 6,35 5*97 5.85 6.2 6.02 6.0 6.1 6.05 19 Unburned Stagnant Lodgepole Fine 4 .20 4.20 5.05 5.05 5.70 5*70 5.95 5.95 6.1 6.1 # COMPARE WITH MAP SITE 12 77 o TABLE 16 THE E F F E C T OF FIRE ON THE .ORGANIC MATTER CONTENT OF THE S O I L (IN PERCENT). MAP SITE NUMBER DESCRIPTION Ao AVERAGE A2 AVERAGE B2 AVERAGE B3 ' AVERAGE C AVERAGE ' 1 2 1943 Burn of Douglas f i r 19.69 12 .20 15.99 1.28 .39 $83 •79 .60 •69 •30 .21 .25 .45 .32 3 4 Unburned Douglas f i r 56.68 46.01 51.34 •96 1.31 1.13 •50 1-12 •81 •30 - 5 0 •40 •33 , 1 8 .25 5 6 1945 Burn of ..Mixed Stand 11.33 11.47 11.40 1.15 .53 •83 .30' .37 •33 a o .12 • 11 .06 . 0 9 .07 7 Unburned Mixed Stand 19.35 19.35 .79 .79 •44 .44 •22 .22 .06 .06 8 1945 Burn of Lodgepole Pine . 21.66 21.66 1.31 1.31 •52 .52 .10 .10 .06 .06 9 Unburned Lodgepole Pine 73.92 73.92 .1.24 1.24 .58 •58 .15 .15 .09 .09 10 11 1945 Bum of Lodgepole Pine 6.61 11.20 8.90 .94 •94 .94 •53 .42 .47 .15 .16 .15 .08 .12 .10 12 Unburned Lodgepole Pine 26.57 26.57 1.08 1.08 •34 .34 .15 .15 .04 .04 # 14 1945 & 1951 Burn of Lodgepole Pine 5.42 5.78 5.60 .86 .99 • 92 .75 .68 .71 •20 .09 •14 .12 .07 .09 15 .1951 Burn of Lodgepole Pine 18.23 .18.83 1.41 1.41 .83 .83 .26 •26 .17 .17 16 Unburned Lodgepole Pine 29.60 29.60 1.06 1.06 .59 •59 .12 .12 .11 •11 17 18. 1951 Burn Stagnant Lodgepole Pine 17 .79 21.41 19:; 60 1.37 .87 1.12 .71 .92 .81 .28 .48 •38 .11 .30 .20 19 Unburned Stagnant Lodgepole Fine 29.43 29.43 1.23 1.23 1.06 1.06 •46 .46 •30 •30 # COMPARE WITH MAP S I T E 12 -<3 TABLE 17 THE EFFECT OF FIRE UPON TOTAL NITROGEN IN THE SOIL (IN PERCENT) HAP SITE NUMBER DESCRIPTION Ao AVERAGE A 2 AVERAGE B2 AVERAGE B3 AVERAGE AVERAGE O082 • 043 .1 2 1943 Burn of Douglas f i r 1.150 .750 .95 .165 .090 .127 .130 .072 ,101 .080 .035 .057 • 062 3 4 Unburned Douglas f i r 2.390 1.340 1.86 .180 .079 ,129 .089 .053 .071 e074 • 046 .060 .021 .014 .060 .027 • 043 5 6 1945 Burn of Mixed Stand .506 .770 .638 .097 .059 .078 .037 .048 .042 .017 .010 .014 .012 Unburned Mixed Stand ,807 .807 .040 .040 .044 .044 • 023 • 023 ,021 .021 8 1945 Burn of Lodgepole Pine .800 .800 .088 .088 .073 .073 .100 .100 .034 .034 Unburned Lodgepole Pine 1.200 1,200 .069 • 069 .058 .058 • 024 ,024 .024 .024 10 11 1945 Burn of Lodgepole Pine .454 .579 .516 .113 .094 .103 .064 .061 .062 .045 .038 ,041 .051 .034 • 042 12 Unburned Lodgepole Pine .678 .678 .094 • 094 ,075 .075 .029 .029 .021 .021 # 14 1945 & 1951 Burn of Lodgepole Pine .168 .061 .114 .080 .096 .088 .034 .083 ,058 .057 • 045 .051 .015 .042. .028 15 1951 Burn of Lodgepole Pine .990 .990 .107 .107 .086 .086 .039 .039 .035 ,035 16 Unburned Lodgepole Pine 1.096 1.096 .164 .164 .117 .117 .080 .080 .081 .081 17 18 1951 Burn Stagnant Lodgepole Pine .784 2.80 1.792 .030 tlOl .065 .076 .080 .078 .023 .071 .047 .021 .018 .019 19 Unburned Stagnant Lodgepole Fine .651 ,651 .054 .054 .109 ,109 .073 .073 .U49 ,049 # COMPARE WITH MAP SITE 12 -a oo TABLE 18 THE EFFECT OF FIRE UPON THE TOTAL PHDSPHO'ROUS IN THE SOUL (IN PARTS PER MILLION) MAP SITS NUMBER DESCRIPTION Ao AVERAGE A2 AVERAGE B2 AVERAGE. B3 AVERAGE • C AVERAGE 1 2 1943 Burn of Douglas fir 16.32 6.20 11.26 42.86 22.85 32.85 156.37 157.93 157.10 90.82 149.24 120.03 182.72 90.68 131.70 3 4 Unburned Douglas f i r 48.91 18.73 33.82 93.11 75.94 84.52 113.01 105.42 109.21 71.70 122.60 97 .15 180.41 188.80 184.65 5 6 . 1945 Burn of ,Mixed Stand 17.16 17.62 17.39 85.07 86.59 85.83 200.93 235.30 218.11 180.57 189.65 185.11 220.03 242.08 231.05 7 Unburned Mixed Stand 42 .74 42 .74 165.02 165.02 241.22 241.22. 198.98 198.98 198.63 198.63 8 1945 Burn of Lodgepole Pine 35.45 35.45 167.00 167.00 247.06 247.06 201.88 201.88 184.02 184.02 9 Unburned Lodgepole Pine 33.04 33.04 49.71 49.71 96.83 96.83 135.55 135.55 187.08 187.08 10 11 1945 Burn of Lodgepole Pine 149.86 68.83 109.34 108.37 116.59 112.48 226.01 180.31 203.16 90.69 68.05 79.37 126.34 131.93 129.13 12 Unburned Lodgepole Pine 19.94 19.94 75.56 75.56 462.51 462.51 65.29 65.29 90.68 90.68 * 14 1945 & 1951 Burn of Lodgepole Pine 57.35 81.25 69.30 85.18 110.58 97.88 243.99 332.08 288.03 97.51 100.40 98.95 119.67 88.93 104.30 15 1951 Burn of Lodgepole Pine 81.14 81.14 146.31 146.31 274.59 274.59 176.77 176.77 257.47 257.47 16 Unburned Lodgepole Pine 21.66 21.66 20.16 20.16 26.37 26.37 55.16 55.16 36.72 36 .72 17 18 1951 Burn Stagnant Lodgepole Pine 38.14 70.54 54.34 78.31 83.25 80.78 136.21 333.24 234.72 192.62 157.39 175.00 354.48 264.24 309.36 19 Unburned Stagnant Lodgepole Fine 18.67 18.67 157.75 157.75 244.40 244,40 135.39 135.39 198.93 198.93 # COMPARE WITH MAP SITE 12 -a 8 0 T A B L E 1 9 T B E E F F E C T O F F I R E O N T H E 002 S O L U B L E PHOSPHOROUS I N T H E S O I L . . . (PARTS P S R M ILLIE* MAP SITE NUMBER DESCRIPTION Ao AVERAGE A2 AVERAGE B2 AVERAGE 1 2 1943 Burn of Douglas f i r 1 5 . 9 2 5 . 7 6 1 0 . 8 4 2 . 5 7 2 . 0 4 2 , 3 0 . 5 1 . 8 2 . 6 6 3 4 Unburned Douglas f i r 4 7 . 7 2 1 8 . 5 7 3 3 . 1 4 3 . 9 8 3 . 3 0 3 , 6 4 2 . 0 6 2 . 0 5 2 . 0 5 5 6 1945 Burn of Mixed Stand 1 . 9 3 7 . 7 1 4 . 8 2 f ' . 1 0 . 7 1 ° 4 0 . 5 1 . 5 1 . 5 1 7 Unburned Mixed Stand 4 0 . 0 7 4 0 . 0 7 2 . 2 4 2 . 2 4 . 5 0 . 5 0 8 1945 Burn of Lodgepole Pine 1 9 . 0 7 1 9 . 0 7 • 62 . 6 2 . 8 2 . 8 2 9 Unburned Lodgepole Pine 3 2 , 4 5 3 2 . 4 5 1 . 7 6 1 . 7 6 1 . 6 4 1 . 6 4 10 11 1945 Burn of Lodgepole Pine 1 . 0 6 3 . 6 5 2 . 3 5 . 8 2 . 7 2 . 7 7 . 5 1 ' . 3 0 . 4 0 . 12 Unburned Lodgepole Pine. 1 9 . 0 3 1 9 . 0 3 1 . 2 3 1 . 2 3 . 3 0 . 3 0 14 1945 & 1951 Burn of Lodgepole Pine 1 0 . 0 1 1 . 5 2 5 . 7 6 1 . 9 4 . 5 1 1 , 2 2 . 5 1 . 3 0 • 4 0 ' 15 1951 Burn of Lodgepole Pine 1 7 , 6 4 1 7 . 6 4 . 6 2 . 6 2 . 4 2 . 4 2 16 Unburned Lodgepole Pine 2 0 . 8 5 2 0 . 8 5 . 8 4 • 84 . 6 1 . 6 1 17,' 18 1951 Burn Stagnant Lodgepole Pine 2 0 . 0 4 1 6 . 6 1 1 8 , 3 2 . . 7 3 . 6 3 . 6 8 • 93 • 7 2 . 8 2 19 Unburned Stagnant Lodgepole Pine 1 7 . 5 0 1 7 . 5 0 . 3 1 . 3 1 1 . 0 6 1 . 0 6 # COMPARE WITH MAP S I T E 12 CD o 81 TABLE 20 THE EFFECT OF FIRE ON THE CO2SOLUBLE POTASSIUM CONTENT OF TBE SOIL. (PARTS PER MILLION") MAP SITE NUMBER DESCRIPTION Ao AVERAGE A2 AVERAGE B2 AVERAGE 1 2 "1943 Burn of Douglas f i r 22 .86 25.47 24,16 8.75 10.20 9.47 8.23 10.79 '9.51 3 4 Unburned Douglas f i r 31.21 34.00 32.65 15.20 13 .41 14.30 5.67 8.23 6.95 5 6 1945 Burn of Mixed Stand 4.93 12 066 8,79 3.06 2,29 2,67 12.20 3.06 7.63 7 Unburned Mixed Stand 34.84 34.84 14,80 14.80 6.92 6.92 8 1945 Burn of . Lodgepole Pine 23.36 23.36 9.91 9.91 15.48 15,48 9 Unburned Lodgepole Pine 49.44 49.44 8.28 8.28 5.64 5.64 10 11 1945 Burn of Lodgepole Pine 3.45 6.72 5.08 3.33 9.23 6.28 3.32 5.63 4.47 12 Unburned Lodgepole Pine 14.16 14.16 8.21 8.21 3.92 3.92 v 14 1945 & 1951 Burn of Lodgepole Pine 9.48 1.52 5.50 17,66 3.83 10.74 6.18 8.22 7.20 15 1951 Burn of Lodgepole Pine 25.97 25.97 13.06 13.06 7.72 7.72 16 Unburned Lodgepole Pine 28.31 28.31 8.92 8.92 11.65 11.65 17 18 1951 Burn Stagnant Lodgepole Pine 17.61 21.72 19.66 15,10 13.80 14.45 14.05 14.67 14.36 19 Unburned Stagnant Lodgepole Pine 20.10 20.10 15.29 15.29 10.60 10.60 # COMPARE WITH MAP SITE 12 TABLE 21 THE EFFECT OF FIRE ON THE CONTENT OF C02 SOLUBLE CALCIUM IN THE SOIL (PARTS PER MILLION MAP SITE NUMBER DESCRIPTION Ao AVERAGE A2 AVERAGE B2 AVERAGE 1 2 1943 Burn of Douglas f i r 26.16 26.58 26.37 20.09 15.36 17.72 24.69 17.73 21.21 3 4 Unburned Douglas f i r 46.97 31.99 39.48 24.37 19.34 21.85 22.42 24.70 23.56 5 6 1945 Burn of Mixed Stand 9.55 14.87 12.26 9.20 4.59 6.89 13.78 8.42 11.10 7 Unburned r ' Mixed Stand 13.06 13 .06 4.59 4.59 10.18 10.18 8 1945 Burn of Lodgepole Pine 24.14 24.14 14.87 14.87 22.46 22.46 9 Unburned Lodgepole Pine 24.70 24.70 10.87 10.87 14.62 14.62 10 11 1945 Burn of Lodgepole Pine 13.57 12.90 13.23 5.38 10.77 8.07 17.40 11.52 14.41 12 Unburned Lodgepole'Pine 9.63 9 .63 13.86 13.86 14.71 14.71 #13 - 14 1945 & 1951 Burn of Lodgepole Pine L13.87 42.65 78.26 10.74 17.66 14.20 7.72 15.41 11.56 15 1951 Burn of Lodgepole Pine 46.38 46.38 18.02 18.02 19.06 19.06 • 16 Unburned Lodgepole Pine 17.54 17.54 19.68 19.68 22.40 22.40 17 18 .1951 Burn Stagnant Lodgepole Pine 20.31 44.09 32.20 18.74 16.27 17.50 22.02 16.35 19.18 19 Unburned Stagnant Lodgepole Pine 18.48 18.48 18.98 18.98 16.70 16.70 # COMPARE WITH MAP SITE 12 83 TABLE 22 THE EFFECT OF FIRE ON THE CONTENT OF COg SOLUBLE MAGNESIUM IN THE MAP SITE NUMBER DESCRIPTION Ao AVERAGE A2 AVERAGE B2 AVERAGE 1 2 1943 Burn of Douglas f i r 34.13 21.77 8.75 4.08 6.41 10.28 5.65 7.96 3 4 Unburned Douglas f i r 15.28 14.10 14.69 7.60 6.96 7.28 9.79 10.03 9.91 5 6 1945 Burn of Mixed Stand 2.68 7.49 5.08 2.81 1.53 2.17 6.94 4.59 5.76 7 Unburned Mixed Stand 7*84 7.84 4.59 4.59 4.58 4.58 8 1945 Burn of Lodgepole Pine 13.76 13.76 6.26 6.26 5.95 5.93 9 Unburned Lodgepole Pine 23.60 23.60 4.91 4.91 6.92 6.92 10 11 1945 Burn of Lodgepole Pine 6.12 5.37 5.74 2.30 9.49 5.89 5.88 9.73 7.80 12 Unburned Lodgepole Pine 9.63 9.63 9.75 9.75 9.80 9.80 * 14 1945 & 1951 Burn of Lodgepole Pine 31.63 8.12 19.87 15.86 11.26 13.56 9.01 9.24 9.12 15 1951 Burn of Lodgepole Pine 19.79 19.79 7.83 7.83 7.94 7.94 16 Unburned Lodgepole Pine 12.31 12.31 12.60 12.60 12.36 12.36 17 18 1951 Burn Stagnant Lodgepole Pine 8.12 20.44 14.28 6.76 • 5.30 6.03 12.75 6.02 9.38 19 Unburned Stagnant Lodgepole Pine 4.40 4.40 5.79. 5.79 7.95 7.95 # COMPARE WITH MAP SITE 12 CD OJ TABLE 23 THE EFFECT OF FIRE ON THE CONTENT OF C08 SOLUBLE NITRATE IN THE SOIL (IN PARTS PER MILLION*! "~ ' ~ MAP SITE NUMBER DESCRIPTION . Ao AVERAGE A2 AVERAGE B2 AVERAGE 1 • 2 1943 Burn of Douglas f i r •432 .088 .260 .237 - O R ! .159 .515 .S9fi .555 3 4 Unburned Douglas f i r .715 .688 .701 .073 .134 .103 .103 .483 .293 5 6 1945. Burn of Mixed Stand .051 .055 .053 .051 .030 .040 .051 .089 .070 7 Unburned -Mixed Stand .342 .342 .131 .131 .039 .039 8 1945 Burn of Lodgepole Pine .926 .926 .313 .313 .376 .376 9 Unburned Lodgepole Pine 1.017 1.017 .062 .062 .389 .389 10 11 1945 Burn of Lodgepole Pine .063 .080 .071 .061 .082 .071 .255 .297 .276 12 Unburned Lodgepole Pine .158 .158 .143 .143 .609 .609 #14 1945 & 1951 Burn of Lodgepole Pine .274 .038 .156 .358 .583 .470 .710 .416 .563 •> 1 5 1951 Burn of Lodgepole Pine .108 .108 .073 .073 .672 .672 16 Unburned Lodgepole Pine 1.390 1.390 .1730 ;.1730 .154 .154 17 18 1951 Burn. Stagnant Lodgepole Pine .216 .127 .171 .156 .127 .141 . .421 •446 .433 19 Unburned Stagnant Lodgepole Pine .298 .298 .305 .305 .175 .175 # COMPARE WITH MAP SITE 12 J TABLE 24 TBE EFFECT OF FIRE UPON THE BASE EXCHANGE CAPACITY. EXCHANGEABLE BASES, AND THE PERCENT BAJ>E SATURATION . , . . OF A LODGEPOLE PINE SOIL BURNED IN 1945 and 1951.. MAP SITE EXCHANGE CAPACITY EXCHANGEABLE EXCHANGEABLE EXCHANGEABLE DESCRIPTION HORIZON IN CALCIUM IN MAGNESIUM. IN POTASSIUM IN PERCENT BASE NUMBER MILLIEQUIVALENTS MILLIE QUlVS. MILLIEQUiVS, MILLIE QJIVS . SATURATION. PER. 100 GRAMS OF PER.100 GMS. PER. 100 GMS . PER.100 GMS. OVEN DRY SOIL . OVEN DRY SOIL. OVEN DRY SOIL. OVEN DRY SOlLf. Ao 49*06 13.55 4.32 1.04 38.5 UNBURNED ^ 2 11.00 3.76 1.21 .22 47.1 12 LODGEPOLE B 2 10.00 3.10 .96 .12 41.8 .. .PINE. . B3 7.20 3.08 2.83 .17 85.8 C 4.50 2.01 1.16 .18 96.6 Ao 31.00 24.43 5.50 1.07 100.0 1945 AND 1951 i 2 10.00 4.05 1.92 .37 63.4 13 BURN OF % 8.64 2.44 1.36 .25 72.8 LODGEPOLE B 3 5.10 2.60 1.97 • 3 2 95.8 PINE C 3.80 2.25 1.26 .18 97.1 I CD FIGURE 2 . AN OUTCROP OF COAST INTRUSIVE GRANITICS NEAR ROSSMORE LAKE FIGURE 3. COAST INTRUSIVE GRANITIC OUTCROP NEAR LAC LE JEUNE. 88 FIGURE 7. A DEGRADED MORAINE DAMMING LAG LE JEUNE FIGURE 9 . ROSSMORE LAKE 13 MORAINE DAMMED. 91 FIGURE 1 3 , AN ESKER NEAR ROSSMORE LAKE FIGURE 22. 1945 BURN OF LODGEPOLE PINE (COMPARE WITH FIGURE 21). FIGURE 2 3 . 1945 and 1951 BURN OF LODGEPOLE PINE. (COMPARE WITH FIGURE 21) . 97 FIGURE 24. 1951 BURN O F LODGEPOLE PINE FIGURE 25. UNBURNED LODGEPOLE PINE 100 IA. Scale .40 Chains = I lnch_ 1936 FIRE 1943 FIRE 1945 FIRE 1951 FIRE IMMATJRE TIMBER OPEN RANGE NON- COMMERCIAL COVER MAIN TRAVELLED ROUTES = = = = SECONDARY ROUTES TRAILS MERCHANTABLE TIMBER ® 1 2 SOIL SAMPLE SITES Traced from B.C. Forest Service Map R44 titled 'The Long Lake Forest' - E F F E C T S OF FIRE ON SOIL. I AO L E J E U N E B ,G— K E Y M A P SHOWING TOPOGRAPHY AND LOCATION OF FIRES_ August 3 , 1953 To Accompany Thesis Submitted by J .D .BEATON 101 BIBLIOGRAPHY 1. Alway, P.J,, and CO. Rost, 1928. Effect of forest f i r e s upon composition and productivity of a s o i l . Proc. of the Internatl, Soc, of So i l S c i . , 3 : 546-576. 2. Alway, P.J., andP.R. McMiller. 1933. The floor of , . some northern Minnesota forests. Amer. S o i l Survey Assoc. Bui., 14 : 11-13. 3. Anon. 1945. Great Dismal Swamp may become a national f orest.., Jour. Forestry, 43 s 824. 4. Arend, John L. 1941. Inf i l t r a t i o n as affected by the forest f l o o r . Proc. of the S o i l S c i . Soc. of Amer., 6 : 430. 5. Arend, John L. 1941. Inf i l t r a t i o n rates of forest soils In the Missouri Ozarks as affected by woods ___ burning and l i t t e r removal. Jour. For,, 39 % ^ 726-729" 6. Association of O f f i c i a l Agricultural Chemists. 1940. O f f i c i a l and tentative methods of analysis' of the Association of O f f i c i a l Agricultural Chemists. 5th ed. x i i - 757 pp. Associa-tion of O f f i c i a l Agricultural Cnemists, Washington, D.C. 7. Auten, J.T. 1933. Porosity and water absorption of forest s o i l s . Jour, of Agr, Res., 46 : 997-1014 8 Auten, J.T, 1934. The effect of forest burning and . pasturing in the Ozarks on the water absorp-tion of forest s o i l s , U.S. Forest Service, Central States Exp. Sta. Note 16. 9, Barnette, R.M. and J.B. Hester1930. Effect of burning upon the accumulation of organic matter i n forest s o i l s . S o i l Sci., 29 : 281-284 10. Bauer, H.D. 1936. Moisture relations in the chaparral of the Santa Monica Mountains, California. Ecological Monographs, 6 : 409-454 11. Beadle, N.C.W. 1940. S o i l temperatures during forest f i r e s and their effect on the survival of "vegetation."jour. Ecology, 28 : 180-192 12. Bennett, H.H. 1932. Relation^of erosion to vegetative changes, S c i , Mo., 35 : 385-415 102 13. Bouyoucos, G.J, 1951, A recaliberation of the hydrometer method for making mechanical analysis of s o i l . Amer, Soc, of Agron. Jour,, 43 : 434-437 14. Boyce, J»S. 1925. Report on forest tree diseases observed in Great Britain and Denmark. A Report of the Office of Investigations in Forest Pathology, Bureau of Plant Industry, Washington, D.C. 87 pp 15. Brown, Carl. B« 1943.' The control of"reservoir s i l t i n g . , U.S. Dept. Agr., Misc. Pub. 521. 166'p.p. 16. Bruner, E.M. 1930. Forestry and forest f i r e s in Arkansas. Ark. Agr.^Col. Ext. Cire. 281. 17. Bujakowsky,sWerner. 1930, ' Beitrag zur Bedeutung des Humus fur die Nahrstoffversorgung unserer Waldbaume. Zeitschr. f . Forst u. Jagdwese, 62: 257-280, (Original not.seen: cited from Forest Soils by Lutz and Chandler,) 18. Burn3, Paul Y. Effect of f i r e on forest soils in the Pine Barren Region of New Jersey, Yale University School of Forestry Bui,, 57. 50 pp. 19. Chapman, H.H. 1942. Management of lobolly pine in the pine hardwood regions in Arkansas and Louisiana west of the Mississippi River, Yale Univ. School of Forestry Bui. ..49. 150 pp. 20. Cockfield, W.E. 1948. Geology and mineral deposits of Nicola Map Area, B r i t i s h Columbia. G.S.C, Memoir 249. 21. Connaughton, C.A. 1935. Forest fires and accelerated erosion. Jour, Forestry, 33 : 751-752. 22. Copley, T.L., A. Forrest, A.C. McCall, and F.G* B e l l . 1944, Investigations In erosion control and reclamation of eroded land at the Central Piedmont Conservation Experiment Station, Statesville, NfcC. 1930-1940. U.S. Dept. Agr., Tech. Bui. 873. 66 pp. 23. Corbet, A.S. 1934. Studies on tropical s o i l microbiology: I I . The bacterial numbers in the s o i l of the Malay.Peninsula. S o i l S ci., 38 : 407-416. 24. Craddock, George, W. 1927. The suecessions1 influence of f i r e in the chaparral type. Thesis - Univer-sity of C a l i f . Library, Berkeley. (Original not seen; cited from Shantz, H.L. 1947. The use of f i r e as a tool in the management of the brush ranges of California. C a l i f . State Bd. Forestry). 103 25, Dawson, G.M. 1895. Report on the area of the Kamloops Sheet B.C. G.S.C. Ann. Rept, for 1894. Part B. 26. Demmon, E.L. The s i l v i c u l t u r a l aspects of the forest .. f i r e problem In the longleaf pine region. Jour, of Forestry, 33 :: 323-331 27. Diebold, C.H. 1942. Effect of f i r e and logging upon the depth of the forest floor in the Adirondack region. Proc* of the So i l S c i . of Amer., 1941. 6 :„409-4l3. , "„ ' 28. Donahue, R.L. 1942. Relation between the carbon content ..of soils under burning and non-burning. Proc, Ann. Convent. Assn. South. Agri. Workers 43:71. 29. Duggeli, M. 1938. Studien uber den Einfluss der un Stadtwald 2ofIngen angrewandten Massnahmen zur Bodenverbesserung auf die Baktierien-flora des Waldbodens. Mitt. d. Schweizer. Centralanstalt. f . d. f p r s t l . Versuchswesen 20:307-444. (Original not seen; cited from Burns, Paul Y. Effect of fir e on forest soils i n the Pine Barren region of New Jersey. Yale Univ. School of Forestry Bui. 57. 50 pp. \ 30. Eaton, E.C. 1932. Relation of f i r e s to water conserva-tion in Los Angeles County. Jour. Forestry, 30 : 605-607. . 31. Eden, Thomas. 1924. Edaphlc factors accompanying the succession after burning oh Harpenden Common. Jour. Ecology, 12 : 267-286 . 32. Edwards, M.V. 1938. Effect of burning of slash on s o i l _and succeeding vegetation. Indian Forester, 64 : 438-443 ' 33. Ehrenberg, Paul. 1922, Die Bodenkolloide, Third ed. v i i i -717 pp. Theodor Steinkqpff, Dresden; Leipzig. (Original not seen; cited from Burns. Paul Y.) 34. E l l i o t t , F.A. and K.B. Pomeroy. 1948. A r t i f i c i a l regenera-tion of lobolly pine on a described burn. Jour, of Forestry, 46 : 296-298. 104 35. Elpatievsky, M.P., S.P. Rumiantsev, and B.K Yarmolovich, 1934. Sposoby oohlstkl le so sek prime nit elnok tipam lesa. (Methods of slash disposal adapted to forest- type s« Tsentralny Naouchno Issledovatelsky Institut Lesnogo Khoziaistva. 100 pp. (Original-not seen; cited from U.S. Forest Service Transit 289.) . 36. Elwell, H.M., H.4, Daniel and £.A. Fehton. 1941. The effect of burning pasture and woodland*. Okla. &gr. Expt. Sta., Bui. B - 247. 37. Eneroth, O• 1928. Bidrag t i l l kannedomen om hygges-branningens inverkan pa marken. (Contri-bution to the knowledge we have of the effect on the s o i l from burning of clearings.) Svenska Skogavardsforeningens Tid s k r i f t , 26 : 685*758. (Original not seen;: cited from UTS. Forest Service Transl. 61.) 38. Finn, R.F. 1943. The leaching of some plant nutrients following the burning of forest l i t t e r . Black Rock Forest Papers 1 (21) : 128-134. 39. Fowells, H.A. and R.E. Stephenson. 1933. Effect of burning on forest s o i l s . S o i l S c i . , 38 : 175-181. 40. Friedrich, C.&. 1951. Forest fi r e - thunderstorm knockout combination for watersheds. N. Rocky Mts. For. and Ra. Sta. Res. Mote 102. 41. F r i t z , Emanuel. 1931. The role of f i r e i n the redwood region. Jour. Forestry, 29 : 939-950. 42. Frothingham, E.D. 1931. Timber growing and logging practises in the Southern Appalachian region. U.S. Dept. Agr.> Tech. Bui. 250. 43. Garren, K.H. 1943. Effects of f i r e on vegetation of the Southeastern United States. Bot. Hev., 9 : 617. 44. Godwin, Gordon. 1938. A regeneration study of represents* tive logged-off lands on Vancouver Island. Forest. Chron., 14 : 61. 45. Graves, H.S. 1910. Protection of forest from f i r e . U.S. Dept. Agr., For. Serv. Bui. 82. 105 46. Greene, S.W. 1935, Relation between winter grass fires and cattle grazing in the longleaf pine b e l t . Jour. Forestry, 33 : 338-341. 47. Greene, S.W. 1935. Effect of annual grass f i r e s on organic matter and other constituents of virgin longleaf pine s o i l s . Jour. Agr. Res., 50 : 809-822. 48. G r i f f i t h , A.L.' 1943.' The effects of burning on the s o i l a.3 a preliminary to a r t i f i c i a l regeneration Indian For. Bui. 130. For. Res. Inst,, Dehra Dun. 34,,pp, 49. Gulisashvili, V.g., and A.I. Stratonovitch. 1935, Fizicheskie syoistya lesnykh pochv i ikh izmenenua pod vluahiem lesokhoziaist-vennykh meropruatu. (Physical charact-eristics of forest soils and the changes they undergo under the influence of forest management,) From a separate edition pub-lished by '"Gpslestekhlzdat , w 147 pp. Leningrad..,' (Original not seen; cited from U.S. Forest Service Transl, 254). 50. Haig, I.T. 1938. Fire in Modern Forest Management. Jour. Forestry, 36 : 1045-1051. 51. Haines, F.M. 1926. A s o i l survey of Hindhead Common, .„ Jour. Ecology, 14 : 33-68 . 52. Hardon, H.J. and J. White. Th. Karte Mededelling van .het Algenieen Proefstation voor den Landbouw, X, 1934-1935, 49-75. (Original not.seen; cited from Edwards, M.y. 1938. Effect of burning of.slash on s o i l and succeeding vegetation. Indian Forester, 64 : 438-443,) 53. Harper, V.C. 1944. Effects of f i r e on gum yields of longleaf and slash pines, U.S. Dept. Agr., Circ. 710. 42 pp. 54. Heiberg, S.6. 1937. Nomenclature of forest humus layers. Jour. Forestry, 35 : 36-39. 55. Heiberg> S.O. 1939. Forest s o i l in relation to s i l v i c u l -ture. Jour. Forestry, 37 : 42-46. 56. Heiberg, S.O., and R.F. Chandler. 1941. A- revised nomen-clature of forest humus layers for the north-- eastern United States. S o i l Sci., 52 :87-100. 106 57. Hendricks, B .A •» and Jerry M. Johnson, 1944. Effects of f i r e on.steep mountain slopes in central Arizona. Jour. Forestry, 42 :. 568*571. 58. Hensel, R.L. 1923* Recent studies on the effect of .burning on grassland vegetation. Ecology, 4 : 183-188. .. 59. Hervey, JD.F. 1949. Reaction of California annual plant . .community to f i r e . Jour. Range Mgmt., 2 (3) : 116-121. 60. Hess, E. 1929. Le sol et l a foret. Etudes pedolog-iques, appliquees aux sols forestiers. Mitt, d. Schweizer. Centralanatalt f . d. f o r s t l . Versuehswesen. 15 : 5-50. (Original hot 3 e e n ; cited from Burns, Paul Y.)^ 61. Heyward, Frank, and R.M. Barnette. 1^34. Effect of frequent _ f i r e s on chemical composition of forest soils in the longleaf pine region. Florida Agr. Exp. Sta., Tech. Bui. 265. 39 pp. 62. Heyward, Frank, R.M. Barnette, and A.M. Tissot.' 1936. Florida Agr. Exp. Sta., Bui. 302. 63. Heyward, Frank, and A.N. Tissot. 1936. Some changes . i n the s o i l fauna associated with forest f i r e s i n the longleaf pine region. Ecology, 17 : 659-666 , 64. Heyward, Frank. 1936. Soil changes associated with forest • . f i r e s in the longleaf pine region of the South. Amer. Soil Survey Assn. Bui. 17 pp. 41-42. 65. Heyward, Frank. 1937. The effect offrequent f i r e s on . profile development of longleaf pine s o i l s . Jour. Forestry, 3_5_ : 23-27. 66. Heyward,. Frank. 1938. So i l temperatures during forest f i r e s in the longleaf pine region. Jour. Forestry, 36 : 478-491. 67. Heyward, Frank. 1939. Some moisture relationships of . soils from burned and unburned longleaf pine forest s o i l s . S o i l S c i . , 47 : 313-374, 68. Hofmann, J.V. 1924. The natural regeneration of Douglas . f i r in the.Pacific Northwest, U.S. Dept. Agr., Bui. 1200. 69. Hole, R.S. 1911. On some Indian forest grasses a nd their ^ ©ecology. Indian Forest Memoirs, 1 (1) : 1-126, ~ . , 107 70. Hosking, J.S* 1938. Ignition at low temperatures of the organic matter in s o i l s . Jour. Agric. Science, 28 : 393-400. 71. Humphrey, H.H. 1949. Fire a a means of controlling velvet mesquite, burroweed and cholla on Southern Arizona ranges. Jour. Range Mgmt.,- 2 (4) : 175-182. ^ „ 72. Isaac, L.A. 1930. Seedling survival on burned and unburned surfaces. Jour. Forestry, 28 : 569-571. 73. Isaac, L.A«* and H.G. Hopkins. 1937. The forest s o i l of , _ the Douglas, f i r region and changes wrought upon i t by logging and slash burning. Ecology, 18,: 264-279. „ 74* Isaac, L.A. 1940. Vegetative Succession following logging in the Douglas f i r region with special reference to f i r e . Jour, of Forestry, 38 : 716-721. 75. Jamwal, H.S. 1939. Effect of burning of slash on s o i l and succeeding vegetation. Indian Forester, 65 : 39-42. 76. Joffe, J.S. 1939. Condensed report of work done and plans . for future work at the Lebanon Forest by the Soils Department of the ..New J. Agr. Exp. Sta. Unpubl. maso New Jersey Dept. Conservation and Economic Dept. (Original not seen; cited from Burns, Paul Y.) 77. Johnston, W.M. 1940. In f i l t r a t i o n capacity of a forest s o i l as influenced by l i t t e r . Jour. Foresty, 38 : 520. 78. Kittredge, J. 1938. Comparative i n f i l t r a t i o n in the forest and open. Jour. Forestry, 36 : 1156-1157.' . 79. Kivekas, J. 1939. Koskivililjelyksen ualkutus eraisun maan ominaisuuksun. (Uber den Elnfluss der Brandkultur auf linige Eigenschaften des Bodens.) (German summary pp. 43-44). Comm. Inst. For. Fenniae, 27 : 1-44. (Original not seen; cited from Burns, Paul Y.) 80. Kbtok, E.I. 1931. Erosion: a problem i n forestry. . Jour. Forestry, 29 : 193-198. 81. Larsen, J.A. 1925. Natural reproduction after forest "fires in Northern Idaho. Jour. Agric. Res., 30 : 1177-1197. 1G8 82» Laurie, M.S. 1939. Note on effect of slash burning on s o i l and succeeding vegetation. Indian Pore3ter, 65 : 43-45. 83. Learner, R.W., and' B. Shaw. 1944. A simple apparatus for measuring hon capillary porosity on an ex-tensive scale. Amer. Soc. of Agron. Jour.,-33 : 1003. 84. Leningen, Westerburg. Wm. 1930. F e r t i l i t y in Forestry. U.S. Forest Service Trans. 201. 85. Love, R.M., and B.J. Jones. 1947. Improving California brush ranges. C a l i f . Agr. Exp. Sta. Circ. 371. ._ . '. 86. Love joy, P.S. 1921. The effect of forest fires upon the s o i l of the North Lake States. 22nd Ann. Rept. Mich. Academy of Science, pp. 9. 87. Lowdermilk,"W.C. 1930. Influence of forest l i t t e r on runoff, percolation and erosion. Jour. Forestry, 28 : 474-491. 88. Lunt, H.A. 1937. The effect of forest l i t t e r removal upon the structure of the mineral s o i l . Jour. Forestry, 35 : 33-36. 89. Lunt, H.Ao 1941. A pot culture experiment with un-disturbed forest s o i l . Proc. of the S o i l S c i . S o c of Amer., 6 : 403. 90. Lunt, H.A. 1948. Forest"Soils of Connecticut. Connect. Agr. Exp. Sta..Bui. 523. 91. Lutz, H.J. 1934. Ecological relations in the pitch pine plains of southern New Jersey. Yale Univ., School of Forestry.^ Bui. 38. 81 pp. 92. Lutz, H.J. 1950. Forest fires in Alaska damage more than timber.., Alaska For. Res. Centre, Tech. Notes. 5... . " 93. McArdle, R.F., and L.A. Isaac. 1934. The ecological aspects of natural regeneration of Douglas f i r in the Pacific Northwest. Proc. of the Fac. S c i . Cong., 5 : 4009-4015. 94. McCulloch, W.F. i944. n Slash burning. Forestry Chronicle 20 : i l l . 95. Madson, A.B. 1943. Letter to Dean C.B. Hutchinson, Feb. 10, 1943, and Report. (Original not seen; cited from Shantz, H.L.) 109 96. Marshall, R., and C. A v e r l i l . 1928, S o i l alkalinity on recent burns. Ecology, 9 : 533. 97. Megennis, H.G. 1935. Effect of cover on surface runoff and erosion in the loessial uplands of Mississippi. U.S. Dept. Agr.,- Circ. 347. 68 pp. 98. Mlchaelis, C. 1948. The effect of f i r e on a hardwood plantation. Quart. Jour. Forestry, 42 : 51. 99. Milne, G. 1933. Tropical Agriculture, 10 : 179. 100. Minckler, L..S-. 1945. Re forest rat ion in the spruce type in the Southern Appalachians. Jour. Forestry, 43 : 349-356. 101. Osborn, J.B. 1931. Some physical properties of the . wattle soils of Natal. So. Afr. Jour. S c i . , 28 : 207-221. ^ ' ' „ 102. Pardee, Geo. C. 1932. Forestry i n the state-wide water plan. A report of Governor Rolph's Honorary Watershed Committee. State of Calif.. Dept of Nat. Res. Div. of Forestry. January 14, 1932. 103. Pearse, A-S. 1943. Effects of burning over and raking-off l i t t e r on certain s o i l animals in the Duke Forest. Amer. Midi. Nat.,. 29 : 406-424. 104. Pechanec, J.F., and G. Stewart. 1944. Sagebrush burning -.good and bad. U.S. Dept. Agr., Farmers Bui. - 1948. y, 105. - Peech, Michael, and Leah English. 1944. Rapid Micro-chemical s o i l tests. S o i l S c i . , 57 : 167-195. 106. Peech, M., L.T. Alexander, L.A. Dean and J.F. Reed. 1947. Methods of s o i l analysis for s o i l - f e r t i l i t y investigations. U.S. Dept. Agr., Circ. 757. 25 pp. . 107. Perry, G.S. 1931. Some chemical and physical effects of forest fires on s o i l s . Proc. Pa. Acad. S c i . , 5 : 123-127. 108. Perry, G.S., and CA. Coover. 1933. Some "effects of fi r e on forest soils of Snowy Mountain, Mont Alto State Forest, Proc,.Pa. Acad. Sci.,?:- : 43«49, 109. P h i l l i p s , J.F.V. 1930. Fire: i t s infiuence"on biotic communities and physical factors i n South and East Af r i c a . So. Afr. Jour. Sci., 27: 352-367. 110 110. Plummer, P.O. 1911. Chaparral, U.S. Forest Service . Bui, 85. 48 pp. . . 111. Remezov, N.P. 1941. Ammonifidatsiya i n i t r i f i k a t s i y a v lesnykh pochvakh. (Ammonification and n i t r i f i c a t i o n In forest soils.) Trud. vsesoyuz. nauchnoissledov. Inst, lesnojo Khoz., 24 : 89-128. (Original not seen; cited from.For. Abstr., 7 : 408. 1946. 112. Rideout, E.P. 1949. A study of slash burning and i t s effect ori a Brit i s h Columbia s o i l . Unpub-lished Master's Thesis, University of Briti s h Columbia, Department of Agronomy. 68 pp. . 113. Rowe, P.B. 1941, Some factors of the hydrology of the Sierra Nevada f o o t h i l l s * Trans, of the American Geophysical Union, Part 1. Pp. 90-100. 114. Russel, E.J., Soil Conditions and Plant Growth, London, Longmans, Green and Co., 1950. p. 208.. 115. Rutledge, A. 1928. Forest f i r e destroys deer, grouse, bear and other w i l d l i f e . U.S. Dept. Agr., Yearbook of Agriculture 1928: 315-316. 116. Salisbury, E.J. 1925. The vegetation of the forest of .Wyre, Jour. Ecology, 13: 314-321. 117., Sampson, A.W. 1944. Plant succession on burned chaparral lands in Northern California. C a l i f . Agr. Exp. Sta. Bui. 685. 144 pp. 118. Sampson, A.W. 1946. Chapter 19 - Burning to improve the range for grazing. Mss Textbook Chapter. (Original not seen; cited from Shantz, H.L«) 119. Schollenburger, C.J. and Simon, R.H. 1945. Deter-mination of Exchange Capacity and.Exchange-able Bases in S o i l Ammonium Acetate Method Soi l Sci., 59: 13-24.\ 120. Schreiner, Oswald, and Eibert. C. Lathrop, 1912. The Chemistry of steam-heated s o i l s . U.S. Dept. Agr., Bureau of Soils . Bui. 89: 37 pp. ; I l l 121. Seaver, F.J., and E.D. Clark. 1921, Biochemcial studies on soils subjected to dry heat. Biochem. Bui, 1 : 414-427. 122. Shantz, H.L. 1947. The use of f i r e as a tool in the ..management of the brush ranges of California. California State Board of Forestry, Sacra-mento. 156 pp. 123. Shelton, W.R., and H . J . Harper. 1941. A rapid method for the determination o f total phosphorous in s o i l and plant material. J o u r , of Sci., 15 : 124. Shirley, H.L. i932. Does light burning stimulate aspen suckers? II J o u r . Forestry, 30 : 419-420, 125. Sims, Ivan. H., E.N. Munns, and J o h n T. Auten. 1938. Management of forest s o i l s , in soils and Men. Yearbook of Agriculture, 1938. U.S., Dept. of Agr« Pp. 737-750. 126. Soils - Brown podzolic. In Soils and Men, Yearbook of Agriculture, 1938. U.S. Dept. of Agr. * Pp. 1029 - 1030. * . 127. Sreenivason, A.» and R.K. Aurangabadkar. 1940. Effect of fire-heating on the properties of black cotton s o i l in comparison with those of grey and humus-treated s o i l s . S o i l S c i . , 50 : 449-462. 128. Stepanov, N. 1925. Fezeko-khemecheskee osovennoste pochv lesnigarei. (Phys'icochemical characteristics of s o i l of forest burns.) Troody po lesnomu opytnomu dyelu. Naradnui komessariiat zem-ledelei r.s.f.s.r., Upravlenic lesame. Issue II (LXVI) Moscow. Fp 58-84. (Original not seen; cited from Burns, Paul Y.) 129. Stobbe, P.G. Comparative Study of the Grey Brown Podsolic and Brown Forest Soils of Southern Ontario and • Southern Quebec. Unpublished Doctor's Thesis. 130. Sushkina, N.N. 1933. N i t r i f i k a t s i a v lessnykh pochvakh v zavissimosti ot sostava nasjdenia, rubkl i ognevoi ochistoka lessosek. (Nitrification of forest soils with reference to the composition of the stands, cutting and f i r e . ) Bui. of the U.S.S.R. Academy of S c i . (Original not seen; cited from U.S. Forest Service. Transl. 56. 4 9~pp. 112 131 • Tarrant, Robert P., and Leo, A. Isaac, and Robert F» Chandler Jr. 1951, Observations on l i t t e r f a l l and foliage nutrient content of some Pacific Northwest tree species. Jour. . Forestry 49: 914 - 915. 132. Teakle, L.J.H. Phosphate in the s o i l solution as affected . by reaction and cation concentration. S o i l Sci., 25 : 143 - 161. 133. The National S o i l and F e r t i l i z e r Research Committee. S o i l Testing i n the United States prepared by The S o i l Test Work Group. 134ft The National S o i l Survey Committee. Report of the Sub-Committee oh Chemical and Physical Analysis. (Presented at the N.S.S.C. Meetings at Guelph, Ontario, 1948. 135. Thome, D.W., and H.B. Peterson. Irrigated Soils, their f e r t i l i t y , and management, Philadelphia, The Blakiston Company, 1949. p 53. 136. Tisdale, E.W. 1950, Grazing of forest lands in interior B r i t i s h Columbia. Jour. Forestry, 48 : 856-860. 137. Topham, P.A» 1933. ~A Letter to Nature. Vol. 132': 102. 138. Trimble, G.R., and N.R. Tripp. 1949. Some effects of f i r e and cutting on forest soils i n the lodge-pole pine forests of the Northern Rocky Mount-ains. Jour. Forestry, 47 : 640-742. 139. Tryon, E.H. 1948. Effect of charcoal on certain physical, chemical and biological properties of forest s o i l s . Ecol. Monographs, 18 : 81-115. 140* U.S. Dept. Agr., Bureau of Plant Industry, Soils and Agricultural Engineering Guide for Textural Classification. 1947. 141. Veihmeyer, F.S.., and C.N. Johnson. 1944. Soil-moisture records from burned and unburned plots in certain grazing areas of California.' Trans, of the American Geophysical Union. Part I. PP° 72-88. 142* Wahlenberg, W.G. 1935. Effect of f i r e and grazing on s o i l properties and the natural reproduction of longleaf pine. Jour. Forestry, 33 : 331-337. 143. Wahlenberg, W.G. 1937. Pasturing woodland in relation to southern forestry. Jour. Forestry, 35 : 550-556. 113 144* Wahleriberg, W.G., S.W* Greene, and H.R. Reed. 1939* Effects of. f i r e and cattle grazing on longleaf pine lands as studied at McNeill, Mississippi. U.S. Dept. Agr., Tech. Bui. 683. 52 pp. 145. Walker, H.R. 1953. Acting Officer-in-Charge, Victoria City Weather Office, Gonzales Observatory, Victoria, B.C. Personal Correspondence. 146. Wilcox, J.C. 1949. Some factors affecting apple yields in the Okanagan valley. S c i . Agr., 29 : 27-44. 147. Wilcox, J.C. per Stevenson, D.S. 1953. Personal Correspondence© 148. Worley, P.P. 1933. Forest fir e s i n relation to s o i l „ f e r t i l i t y . Nature, 131 : 787-788.
Thesis/Dissertation
eng
Soil Science
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Graduate
Influence of burning on the soil in the timber range area of Lac Le Jeune, B.C.
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