Open Collections

UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Changes in the carabid beetle community of the Sicamous Creek research site in response to prescribed… Lavallee, Susanne L. 1999

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-ubc_1999-0200.pdf [ 3.55MB ]
Metadata
JSON: 831-1.0089098.json
JSON-LD: 831-1.0089098-ld.json
RDF/XML (Pretty): 831-1.0089098-rdf.xml
RDF/JSON: 831-1.0089098-rdf.json
Turtle: 831-1.0089098-turtle.txt
N-Triples: 831-1.0089098-rdf-ntriples.txt
Original Record: 831-1.0089098-source.json
Full Text
831-1.0089098-fulltext.txt
Citation
831-1.0089098.ris

Full Text

C H A N G E S I N T H E C A R A B I D B E E T L E C O M M U N I T Y O F T H E S I C A M O U S C R E E K R E S E A R C H SITE I N R E S P O N S E T O P R E S C R I B E D L O G G I N G P R A C T I C E S by S U S A N N E L . L A V A L L E E B.Sc. University of British Columbia, 1994 A T H E S I S S U B M I T T E D I N P A R T I A L F U L F I L L M E N T O F T H E R E Q U I R E M E N T S F O R T H E D E G R E E O F M A S T E R , . O F S C I E N C E in T H E F A C U L T Y O F G R A D U A T E S T U D I E S ( D E P A R T M E N T O F Z O O L O G Y ) We accept this thesis as conforming to the required standard T H E U N I V E R S I T Y O F B R I T I S H C O L U M B I A A p r i l , 1999 © Susanne L . Lavallee, 1999 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department The University of British Columbia Vancouver, Canada DE-6 (2/88) Abstract Carabid beetles (Order Coleoptera, Family Carabidae) are an important part of forest diversity and play a role in assessing forest health. This study is an important advancement in the study of carabid beetles in the environment as it is the first to continuously sample a population in pre-treatment and post-treatment states. Changes within the carabid assemblage were monitored as different harvesting regimes were applied. The five treatments examined were: 10, 1.0, and 0.1 hectare clearcuts, 25% Individual Tree Selection (I.T.S.) and controls (uncut). Results showed that species richness increased within clearcut habitats for all treatments, but not necessarily within forested and edge habitat for all treatments. Edge habitat richness was lower in some 0 treatments. Species diversity indices showed similar changes for these habitats. Species evenness analysis showed that forest and clearcut habitats are dominated by a few species, but that edge habitat has a more even hierarchy. N o differences in habitat use were detected for most species, except for a few "new" species (ones that appeared after logging occurred). For Scaphinotus angusticollis (Fischer V o n Waldheim) there was a significant drop in abundance in 25% I.T.S. plots after harvesting as compared to 0.1 hectare plots, indicating that some undisturbed forest habitat is required by this species. i i Table of Contents Abstract i i Table of Contents i i i Lis t o f Tables v List o f Figures v i Acknowledgements ix Introduction 1 The Healthy Forest 1 Forestry in British Columbia 2 Insects in the Forest 3 Carabid Beetles in Surveys 4 Carabid Ecology 5 Carabids of Sicamous Creek 7 Materials and Methods 10 Site Information 10 Logging Manipulations 11 Arthropod Collection 13 Data Processing 14 Species Richness 15 Species Evenness 15 Heterogeneity Measures 15 Single Species Analysis • 16 Results : 17 Species Richness 23 Whittaker Plots 27 Heterogeneity Indices • 43 m Results (Cont'd) Intraspecific Comparison 53 Clearcut Size 53 25% I.T.S. and 0.1 hectare removals 54 Forest Margin 55 Total Treatment Responses 56 Discussion 57 Scale of Observation 58 Species Richness 59 Species Eveness 62 Heterogeneity Indices 63 Intraspecific Comparisions 64 Clearcut Sizes 64 Forest Fragmentation 65 Total Treatment Responses 66 Conclusion 67 Literature Cited 68 Appendix 1 73 iv List of Tables Table 1 : Species presence/absence data for experimental treatments 18 Table 2: Species attributes (Lindroth, 1961-1969) 20 Table 3: Total catch from pitfall traps at Sicamous Creek Study Site by treatment 22 v List of Figures Figure 1: Englemann Spruce Subalpine Fir (ESSF) biogeoclimatic zone in British Columbia , 10 Figure 2: Layout of the Sicamous Creek Study Site, showing clearcut sizes and cutblock layout 12 Figure 3: Trap layout in each treatment block of Sicamous Creek 13 Figure 4: Species richness for early August samples from control treatment blocks 23 Figure 5: Species richness for early August samples from 0.1 hectare treatment blocks 24 Figure 6: Species richness for early August samples from 1.0 hectare treatment blocks 25 Figure 7: Species richness for early August samples from 10 hectare treatment blocks 26 Figure 8: Species richness for early August samples from 25% I.T.S. removal treatment blocks 27 Figure 9: Whittaker plots of rank/abundance for pre-treatment control data 28 Figure 10: Whittaker plots of rank/abundance for post-treatment control data 29 Figure 11: Whittaker plots of rank/abundance for 0.1 hectare blocks pre-treatment 30 Figure 12: Whittaker plots of rank/abundance for forested habitat in 0.1 hectare blocks post-treatment 31 Figure 13: Whittaker plots of rank/abundance for edge habitat in 0.1 hectare blocks post-treatment 32 Figure 14: Whittaker plots of rank/abundance for clearcut habitat in 0.1 hectare blocks post-treatment 33 Figure 15: Whittaker plots of rank/abundance for 1.0 hectare blocks pre-treatment 34 Figure 16: Whittaker plots of rank/abundance for forested habitat in 1.0 hectare blocks post-treatment 35 Figure 17: Whittaker plots of rank/abundance for edge habitat in 1.0 hectare blocks post-treatment 36 vi Figure 18: Whittaker plots of rank/abundance for clearcut habitat in 1.0 hectare blocks post-treatment 37 Figure 19: Whittaker plots of rank/abundance for 10 hectare blocks pre-treatment 38 Figure 20: Whittaker plots of rank/abundance for forested habitat in 10 hectare blocks post-treatment 39 Figure 21: Whittaker plots of rank/abundance for edge habitat in 10 hectare blocks post-treatment 40 Figure 22: Whittaker plots of rank/abundance for clearcut habitat in 10 hectare blocks post-treatment 41 Figure 23: Whittaker plots of rank/abundance for pre-treatment 25% I.T.S. blocks 42 Figure 24: Whittaker plots of rank/abundance for post-treatment 25% I.T.S. blocks 42 Figure 25: Shannon-Wiener Diversity Index values for control treatment 44 Figure 26: Simpson Index values for control treatment 44 Figure 27: Shannon-Wiener Diversity Index values for 0.1 hectare treatment 46 Figure 28: Simpson Index values for 0.1 hectare treatment 46 Figure 29: Shannon-Wiener Diversity Index values for 1.0 hectare treatment 48 Figure 30: Simpson Index values for 1.0 hectare treatment 48 Figure 31: Shannon-Wiener Diversity Index values for 10 hectare treatment 50 Figure 32: Simpson Index values for 10 hectare treatment 50 Figure 33: Shannon-Wiener Diversity Index values for 25% ITS treatment 52 Figure 34: Simpson Index values for 25% ITS treatment 52 v i i Figure 35: Mean number of Harpalus nigritarsus, Bembidion breve, and Pterostichus adstrictus per trap for pooled post-treatment data in 0.1, 1.0, and 10 hectare treatments. A N O V A results: F(crit.)= 3.68 Harpalus nigritarsus F=4.45 Bembidion breve F=13.35 Pterostichus adstrictus F=3.56 53 Figure 36: Mean number of Scaphinotus angusticollis per trap in 0.1 hectare and 25% I.T.S. removal for pooled post-treatment data. A N O V A results: F(crit.)=4.96, F=5.78 54 Figure 37: Mean number of Scaphinotus angusticollis, Nebria crassicornis, and Calathus advena per trap for pooled post-treatment data. A N O V A results: F(crit.)=3.98 Scaphinotus angusticollis F=l.14 Nebria crassicornis F=0.49 Calathus advena F=2.12 55 Figure 38: Mean number of Pterostichus riparia, Leistus ferruginosus, Scaphinotus marginatus, and Scaphinotus angusticollis per trap for pooled post-treatment data. A N O V A results: F(crit.)=3.21 Pterostichus riparia F=0.74 Leistus ferruginosus F=2.49 Scaphinotus marginatus F=0.12 Scaphinotus angusticollis F=2.55 56 v i i i Acknowledgements Thanks to my committee members: Dr. Geoff Scudder ^ Dr. John McLean Dr. Martin Adamson Thanks to all the people who made the Sicamous Creek Project possible: Countless unnamed field technicians who gave everything they had, and sometimes more; Randy Daley without his dedicated and meticulous work, this would only be 2/5 of a thesis; Dave Huggard for his invaluable information and excellent advice; Dr. Walt Klenner for giving me the chance of a lifetime, and his devotion to the project. M y thanks to those who were there when I needed them: M r . D . Shpeley for his patient work at identifications; Jeff Jarrett, Karen Needham, Jenny Heron, Peggy L i u , and Susanna Guthrie for giving their lab-mate a lot of good advice and support; Jocylyn M c D o w e l l for showing me the path to enlightenment; Katherine Maxcy for her wonderful editing skills; Shannon Bennett, Dr. John Spence, and Dr. John Richardson for statistical advice; Launi Lucas for her wonderful expertise with computers. Also , thanks to those who have made this easier: Jean and E d Lavallee for their confidence in me, and for being there; Darren Benson for all the mugs of tea, and late nights on the computer; M y excellent friends for always being interested and patient. Thanks to the sources of funding for the Sicamous Creek Project: the British Columbia Ministry of Forests and Forest Renewal British Columbia. Research funding was also provided by research grants from the National Sciences and Engineering Resource Council of Canada to Dr. G . G . E . Scudder. ix Introduction The Healthy Forest Forests are one of the most complex ecosystems of our planet (McNeely, 1994). The structural diversity of trees and plants give many layers to forest habitat both above and below ground. Root systems remove minerals and water from the soil, leaves and needles draw gasses from the atmosphere. There is, however, far more to forests than trees. Our perception of what a healthy forest includes depends heavily on our level of exposure to less charismatic species (Haack and Byler, 1993). Nutrient cycling in the environment depends on many organisms that often go unseen (Asquith et al, 1990); they may be either soil dwelling, or hunt in the litter layer of forests. Millipedes, for instance, play an important role in breaking down leaf litter so that decomposers and plants may reuse this source of nutrients (Kevan, 1962). Collembola are one of the most abundant organisms in forest habitats and are also vital to the decay of organic matter (Kevan, 1962). Predators of microfauna limit the amount of damage to trees and shrubs by defoliators in check (Thiele, 1977), and are a part of a complex set of nutrient cycles that form a forest (McNeeley, 1994). When the web of interactions is disturbed, by either natural or human forces, there are changes within the processes of an ecosystem, resulting in reestablishment in a way that differs from the original patterns (McNeeley, 1994). For example, when a tree dies from root rot and falls over, a small opening is created in the forest canopy, which may favour one species over another, allowing it to establish dominance in this tiny space. Logging is a larger scale disturbance, creating conditions on a microclimate scale which may vary more dramatically (Chen et al., 1995). Our knowledge of how logging and natural disturbance change the habitats 1 that forest animals and plants depend on is crucial to minimizing the impact of humans on forest ecosystems and repairing damage that occurs. Forestry in British Columbia The forests of British Columbia are an important resource to the provincial economy. In 1997, over 71 million cubic meters of timber were harvested in British Columbia alone (National Forestry Database, 1998). This timber was used to manufacture paper, lumber, log houses, as well as many other secondary and tertiary products. Forestry provides over 90,000 jobs to British Columbians (Still et al, 1994), and is an economic basis for this province. The impact of human's tree removal is of primary concern, because maintaining forests as a renewable resource is in the best interests of British Columbia's economy and because our future enjoyment of forests relies on it. Studies on how forest-dwelling organisms change their habitat, food sources, and even survive the process of logging illustrate ways we can reduce our impact on forests. Studies (Hammond, 1993; Pojar, 1993; McNeely, 1994) have indicated that ecosystems are adapted to renew after changes that imitate the natural disturbance regime (eg. forest fires), and suggest that logging should be done on a similar scale. Based on this theory, the Forest Practices Code requires the sizes of clearcut openings be adjusted according to the prescribed disturbance regime. Some researchers (Haila et al, 1994) are skeptical of whether logging and natural disturbances like forest fires parallel in their level of disturbance to organisms of a forest. More investigation into this theory is needed. Impacts of logging are well known for game species like elk and deer, as these are the organisms that managers and the general public are most familiar with in forest ecosystems 2 (Haack and Byler, 1993; Samways, 1993). However, restoration of forest health should include consideration of many organisms, to provide the most well-rounded management plan (Harris, 1988; Boyle, 1991; Haack and Byler, 1993; McNeeley, 1994; Samways, 1993). Insects in the Forest Despite the fact that they play a vital role in maintenance of a healthy forest, insects are one of the components of forests most often ignored by managers, unless they are pest species at work. However, insect predators control populations of other insects that are deleterious to the forest ecosystem (Kevan, 1962; Thiele, 1977), and insects are also essential to nutrient cycling (Asquithera/ . , 1990). Despite their poor reputation with humans (Samways, 1993), insects are a valuable tool to biologists in studying the impacts of forest management and are more frequently being included in ecosystem assessment (Fisher, 1998). For example, monitoring of forest health in the Pacific Northwest States now includes surveying of non-pest insects (Lattin, 1993), in recognition that changes in the insect fauna indicate important shifts in an environment. Assessment of the temporal landscape of hardwood forests in England (Terrell-Nield, 1990) has shown that some insect species are particularly good indicators of woodland age and structural diversity. The small size and ease of trapping insects also makes them ideal for study in long-term monitoring (Weaver, 1995). 3 Carabid Beetles in Surveys Some groups of insects are chosen for scientific study much more frequently than others. Carabid beetles (Order Coleoptera, Family Carabidae) are one such group. On an international scale, as well as here in Canada, carabids are one of the insect families frequently chosen for biodiversity and disturbance assays. Reasons for selecting carabids as a study subject are clear. Carabids have wel l -documented distributions, and much work has been done to establish their habitat associations (Thiele, 1977; den Boer, 1986). Although there is some debate over habitat specificity within some species, there is little doubt that most carabids are found in association with very specific landscape features, and in narrowly defined microclimates (Duchesne and McAlp ine , 1994; Heijerman and Turin, 1994). Carabids also make good study subjects because they are readily identifiable. They are the only large family of insects in North America for which a comprehensive key to species is available. Dr. Carl Lindroth's 1200 page monograph on carabid beetles (1961-1969) provides a relatively simple guide, based mainly on external morphological features. Carabid beetles have also proven to be sensitive indicators of habitat change, showing greater specificity to microclimate than spiders (Mader, 1984), birds (Haila et al, 1994), and standard vegetational analysis (Refseth, 1980), which are commonly used to assess habitat qualities. 4 Carabid Ecology Carabid beetles are one of the major insect predators in forests (Thiele, 1977). While they may not directly rely upon the diversity of plant life for food, their prey does. Studies have shown that carabid populations have strong correlations with vegetational diversity (Jennings et al, 1986; Baguette and Gerard, 1993). A s the amount of understorey vegetation increases, the diversity of both prey and predators increase (Jennings et al, 1986). Because of this relationship, it is not surprising that as a forest is harvested, certain responses of carabids as a group can be observed. In early serai stages, where vegetation is more diverse, species richness and diversity of carabids is higher (Jennings et al, 1986; Baguette and Gerard, 1993; Halme and Niemela, 1993; Craig, 1995; McDowel l , 1998). Either by competitive exclusion or habitat specialization, carabid communities of mature forests tend to be dominated by large numbers of few species, leading to low estimations of species diversity and richness for such sites (Halme and Niemela, 1993; Craig, 1995; McDowel l , 1998). Carabid species can be classified by their adaptations and responses to habitat change. This is a common method of describing a carabid community response, and gives a tangible idea of how changes affect populations. One of the evolutionary adaptations used to describe a species is flight capability. There is a good evolutionary basis for this classification, which has relevance in habitat alteration or creation on a short-term scale as well . Carabids that live in more stable habitats are evolutionarily selected to invest less energy into the production and use of wings (den Boer, 1970; Holliday, 1991). Carabid species which are strongly associated with forest habitat tend to be brachypterous, apterous, or functionally apterous (i.e. have complete but non-functional wings) (den Boer, 1970; Holliday, 1991). Conversely, species of carabids that are more strongly associated with high levels of habitat disturbance (eg. grasslands or forests which 5 are subject to forest fires) have maintained flight capabilities and are therefore able to disperse to new habitat as it opens up (den Boer, 1970; Holliday, 1991). In recently disturbed areas, which are not normally subject to large-scale disturbance, a succession of species types occurs, from flightless to flight-capable species (Niemela and Spence, 1994). Carabids may also be classified on the basis of their correlations with habitat types and responses to habitat change. Many studies (Refseth, 1980; Niemela et al, 1993; Niemela and Spence, 1994; Craig, 1995; Lemieux, 1998; McDowell, 1998) have sought to identify carabids as old-growth forest specialists, forest specialists, forest generalists, or xerophilous (open-area preferring) species. Habitat associations have strong correlations to flight capabilities, and therefore the evolutionary adaptations of carabids to disturbance levels. Characterization of responses within carabid communities to specific land use plans allows us to map the extent and pattern of change in the forests. Craig (1995) found that one flightless species (Zacotus matthewsii LeConte) could be classified as an old-growth species, meaning that populations were sensitive to change, and would not recolonize areas that had been disturbed. This classification has also been found to be valid for other species in studies of Finnish forests (Niemela et al, 1993). Such species' populations would be irrevocably harmed by logging, as they would not be able to recolonize forest patches within a normal rotation of tree harvesting (Niemela et al, 1993). Even within agricultural settings, flightless carabids have been shown to be sensitive to habitat disruption and to vanish from the carabid community (Turin and den Boer, 1988). Forest specialists are another group of particular interest to insect conservation, as they are also flightless and sensitive to disturbance but may have the ability to utilize or disperse through marginal habitat (Craig, 1995). Generalist carabid species are usually flight-capable 6 carabids that are able to utilize many habitat types and can disperse quickly (Niemela and Spence, 1991) Studies of carabid habitat associations and the changes within assemblages in Western Canada have produced conflicting evidence for habitat specificity of some species (for example, Pterostichus riparia Dejean, in: Niemela et al, 1993 and Lemieux, 1998), making placement of species within ecologically related groups less certain. Clarification of these conflicts is necessary i f carabids are to be a useful tool in habitat assessment for forestry. Carabids of Sicamous Creek In the interest of studying forest biota and their responses to logging, planning of the Sicamous Creek Research Site began in 1990 (Holdstedt and Vyse, 1997). The project sought to provide real evidence for changes that had only been inferred by other studies. Prescribed logging was designed to provide a solid scientific basis for researchers to begin investigations of three clearcut sizes, a uniform cut, and a control, or uncut treatment. Three years of pre-treatment data were collected (from 1992 to 1994), then winter logging was performed, followed by three years of post-treatment data (from 1995 to 1997). This study provided the first record of direct evidence for changes to carabid communities due to logging. A l l other studies in the literature have taken forested and clearcut sites, estimated to be equivalent before logging, and then compared them only after the disturbance, i.e. post-harvest. The Sicamous Creek Project is one of the first to monitor a pre-harvest and post-harvest community from the same area in a continuous manner, directly showing changes in species richness, evenness, and diversity over time. This alone makes 7 findings of the Sicamous Creek Project unique, but there are some more specific questions of interest that are posed in this study. What difference does the size of opening in the forest canopy make to individual species? A s new species move in, do larger openings in the forest canopy make for larger targets? H o w do the original forest species fare in the harsh climate of a clearcut? Studies have indicated that greater levels of disturbance differentially impact carabid species (Halme and Niemela, 1993), but stronger evidence is needed. A comparison of opening size between three clearcut treatments: 0.1, 1.0, and 10 hectares of tree removal, w i l l reveal changes that occur in carabid assemblages and individual species. H o w does fragmentation of forest habitat affect species that are specialized in their use of resources available in forests? This question has been posed in a number of studies (Day and Carthy, 1988; Niemela et al, 1993; Haila et al, 1994; Niemela and Spence, 1994), and one study (Niemela et al, 1993) has indicated that homogenization of forest habitat is detrimental to forest specialists. This question is analyzed in two ways by the Sicamous Creek project. First, individual tree selection, or selective logging, thins a forest's canopy and creates a more homogenous habitat. A comparison between selective logging, and 0.1 hectare clearcut treatments, which create habitats with small reserves of undisturbed forest, can determine i f there are any differences between these two degrees of habitat homogenization for carabids. Second, a comparison of species' numbers caught in forest margins left around clearcuts can illustrate how fragmentation of forest habitat affects certain species. A s clearcut sizes are increased in treatment blocks, the width of untouched forest left around them also increased, because the amount of timber removed from all treatment areas was kept constant in each treatment. 8 The responses of individual species to logging treatments as a whole is also a pertinent question, as there is some controversy over classification of some species of carabids into habitat preference groups. A n examination of the responses of these species to different logging manipulations could help to clarify the grouping of species. 9 Materials and Methods Site Information The Sicamous Creek (also known as Mara Mountain) Project site is located about eight kilometers south by southeast of Sicamous, B C (Huggard and Klenner, 1995). It is in the Monashee mountain range, which is the most western range associated with the Rocky Mountains. The study site consists of a uniform, north-facing slope that ranges in elevation from 1550 to 1750 m encompassing one side of Mara Mountain and the headwaters of Sicamous Creek. It is located in the Englemann Spruce, Subalpine Fir (ESSF) biogeoclimatic zone (Figure 1). ESSF is a widespread biogeoclimatic zone, ranging from the northern reaches of the province to the southern foothills of the Rockies (Meidinger and Pojar, 1991), and covers 13.3 mil l ion hectares of land, or about 14% of the province (Still et al, 1994). Figure 1 Engelmann Spruce-Subalpine Fir (ESSF) biogeoclimatic zone in British Columbia 1 0 Typically, E S S F forests are cold and high in elevation, with Englemann Spruce (Picea englemannii Parry) the predominant tree species in mature overstorey, and Subalpine Fir (Abies lasiocarpa Hook. (Nutt.) in the understorey (Meidinger and Pojar, 1991). Precipitation in this biogeoclimatic zone most commonly falls in the form of snow (Meidinger and Pojar, 1991). The E S S F biogeoclimatic zone is subdivided into fifteen different subzones (Meidinger and Pojar, 1991). The Sicamous Creek site is in a subzone labelled wc2 (wet, cold, level two) (Huggard and Klenner, 1995). It is one of the most severe subzones in the E S S F , as it is under deep snow cover for seven months of the year and has heavy ground frost for an additional two months, limiting the growing season to three months (Meidinger and Pojar, 1991). The predominant understorey at Sicamous Creek is dense Rhododendron albiflorum Hook, (white rhododendron) and Vaccinium sp. (wild blueberry), with large openings of wet, marshy ground interspersed throughout the forest (Huggard and Klenner, 1995). The natural disturbance regime in this subzone is of the lowest level in B C Ministry of Forests classification system, with infrequent, small-scale, and stand originating events creating small openings (Forest Practices Code Biodiversity Handbook, 1995). Tree mortality is usually caused by root rot in the Sicamous Creek study site (Dr. W . Klenner, B C Ministry of Forests Researcher, pers. comm.). Soils are generally shallow and with high mineral content, and highly saturated with water for most of the year (Meidinger and Pojar, 1991). Logging manipulations The Ministry of Forests, Kamloops Region, began designing a fifteen year study of the forest biota at Sicamous Creek project in 1990. The first three years of data collection (1992-1994) were used to collect pre-harvest data and survey the sites for future logging. Road 11 building was done in the winter of 1993, and, owing to the nature of E S S F soil, logging was carried out on the study site in the winter of 1994-1995. The study site was divided into fifteen treatment areas, each approximately 30 hectares in size (Figure 2). Using a randomized block design, three replicates of five treatments were established, including: control (with no tree removal), 10 hectare clearcuts, 1.0 hectare clearcuts, 0.1 hectare clearcuts, and 25 % individual tree selection (referred to as I.T.S.) (Figure 2). The total canopy cover removal for the each treatment area was - 3 3 % of the original 30 hectares, including the area used in landings, roads and tree removal. For ease of reference, treatment blocks were named according to their elevation (A-C) and according to their latitude (1-5) (Figure 2). Further experimental treatments were applied within each of the tree removals, providing a doubly-nested design. Small plots of 0.1 hectares within each type of tree removal were subjected to burning, coarse woody debris removal, coarse woody debris addition, and mounding of coarse woody debris. r~l 25 % Individual Tree Selection (I.T.S.) [HI Complete tree removal (clear cut) I | No tree removal (uncut forest) Figure 2 Layout of the Sicamous Creek Study Site, showing clearcut sizes and cutblock layout. 12 Arthropod collection Three sets of arthropod collections were undertaken, each focussing on a different effect of the treatments at Sicamous Creek. Treatments highlighted were: clearcut sizes, edge effects, and post-logging manipulations (e.g. burning, mounding, coarse woody debris removal, and addition). The research reported on in this thesis only addresses the collections designed to test responses to clearcut sizes. Arthropods were sampled using pitfall traps, designed to sample pre-treatment forest and post-treatment forest habitats equally. Three rings, about five meters in diameter, of five traps were placed in each cutblock, 75 m apart (Figure 3). Each pitfall trap consisted of two 500 ml plastic cups, one inside the other, with the outer cup pierced at the bottom to allow surface water to drain. 100 ml of propylene glycol was added to the inner cup, to act as a ki l l ing agent and a preservative. The pitfall traps were emptied about once every two weeks in the summer months, and once every three months in the winter months. The dates of the collections are given in Appendix 1. Collection samples were strained from the glycol, rinsed with ethanol, and placed in a screw-top plastic container for storage until further processing could be done. ^ " - " • "S^ 75 m •— Torcsl cd ie clearcut Treatment Block F i g u r e 3 Trap layout in each treatment block of Sicamous Creek. 13 The initial stage of coarse sorting identified the invertebrates in the pitfall samples to order, with the exception of the Order Coleoptera, which was identified to family. The carabid beetles separated in this coarse sorting were then identified to species, and representatives of each species were pinned for ease of accurate identification and permanent preservation. Verification of the species identified was done by M r . D . Schpeley, Assistant Curator of the Entomology Museum of the University of Alberta. Permanent storage of the bulk of the carabids captured in this study was in ethanol. Voucher material w i l l be deposited in the Spencer Entomological Museum (at the University of British Columbia), the Royal British Columbia Museum (Victoria), the Canadian National Collection (Ottawa), and the Pacific Forestry Centre (Victoria). Data Processing After initial assessment of the different trapping periods for the presence of species, sums of raw data showed that the early August sampling period was the best time for seasonal emergence of all species and was most consistently sampled throughout the years; early August samples were thus selected for detailed analysis. The selection of this time period is consistent with the findings of another study (Oliver and Beattie, 1996) which found that the best assessment of diversity was produced by summer pitfall trap samples. The early August sampling period chosen for analysis in this study is equivalent to the time period chosen in Oliver and Beattie's study, as it represents the middle of the growing season in this ecosystem. The design terminology used in this thesis requires some clarification, for ease of discussion. "Treatment areas" or "treatment blocks" refers to the fifteen sections of the Sicamous Creek study site. "Control blocks" refers only to treatment areas that did not have any logging occur within them, for both pre-treatment and post-treatment data analysis. In all pre-14 treatment data, treatment blocks were grouped for analysis by the treatments that were to be applied to them (e.g. 25% Individual Tree Selection), even though they were equal in terms of canopy cover and disturbance levels before logging. This was done to minimize the amount of statistical "noise" introduced by unequal sampling effort and site variation between treatments. These pre-treatment data are referred to using the logging application that was scheduled to occur, eg. "pre-treatment 0.1 hectare clearcut blocks". Within some treatments, different habitats are used for analysis and comparison. This is because in the post-treatment state for the three clearcutting treatments (0.1, 1.0 and 10 hectare clearcuts) three habitat types (forested, edge, and clearcut) are created and have different implications on carabid community dynamics, as w i l l be discussed further in this thesis. Species Richness Species richness was analysed yearly for each treatment and for each habitat type within each treatment; this standardized for unequal sample sizes among the habitats, allowing for quantitative comparisons. The number of species was estimated for a chosen minimum sample size for each habitat type within each sampling period, using a process referred to as rarefaction (Ecological Methodology Data Analysis package, Krebs, 1989) Species Evenness Whittaker plots (Krebs, 1989), which plot percent abundance versus species rank, were then constructed for each of the habitat types in the early August sampling period. These plots allow for the visual comparison of the dominance or egality of species within the community. Heterogeneity Measures Simpson and Shannon-Wiener Indices were calculated using the Pisces Data Analysis Program (R. Seaby, I R C House, U K ) . Both indices combine the effects of richness and 15 dominance within a community, allowing for comparison across all treatments, despite differences in sample size and number of individuals caught. The Simpson Index highlights the changes that occur in the most common species, and the Shannon-Wiener Index, a measure of entropy within a system, highlights the rarer species in the assemblage (Magurran, 1988). Single Species Analysis Individual species responses to opening sizes, width of forested margins, and selective logging as compared to 0.1 hectare treatments were analyzed. Mean number of individuals per trap was used to calculate a mean for a chosen treatment unit, depending on the comparison being made. For example, in comparisons of opening sizes, a treatment unit consisted of rings placed only in clearcuts of one size. The treatment unit means were then compared between units using an A N O V A . Treatment unit means were calculated using a Microsoft Access program designed by Dave Huggard (Ph.D. candidate, U B C ) , and A N O V A s were calculated using the data analysis package in Microsoft Excel 4.0. Treatment means for some species were graphed using Sigma Plot to illustrate pertinent relationships. 16 Results The Sicamous Creek study site yielded 25,277 carabid beetles in the pitfall traps over the six years of data collection. About 1485 samples were analyzed. A total of 28 species were identified, belonging to 14 different genera (Table 1). Ten hectare clearcut treatments have the largest number of species "new" to Sicamous Creek, i.e. species found only after logging occurred. O f the 13 "new" species identified in this study, 11 species were found in 10 hectare treatment areas, 9 species were found in 1.0 hectare treatment areas, and only 5 species were found in 0.1 hectare treatment plots, with much overlap in occurrence between treatments (Table 1). O f the four treatments that required logging, the lowest number of "new" species was found in the 25% I.T.S. plots, which only had 3 new species in the post-harvest samples. One of the "new" species, Pterostichus melanarius, was found in every treatment including control areas, an indication of the dispersal capabilities and habitat plasticity of this alien species. Others, such as the European introduced species Amara apricaria and the native species Amara laevipennis were only found in the 10 and 1.0 hectare treatment plots, perhaps indicating a greater habitat specificity. Species that are not native to North America are noted in Table 2. 17 Table 1: Species presence/absence data for experimental treatments. Pre-treatment Post-treatment Species (* denotes "new" species, found only after harvesting) Uncut Contro 1 25% 0.1 ha 1.0 ha 10 ha Agonum metallescens (LeConte)* i i i i i i i i i i i i i ! + Amara apricarius (Paykull)* l l l l l l l l l + Amara idahoana (Casey)* +• + + Amara laevipennis Ki rby* + Bembidion breve Motschulsky + + + + + Bembidion grapii Gyllenhal* + + + Bembidion lampros (Herbsf)* I l l l l l l i i i l + + Calathus advena (LeConte) + + + + + Harpalus animosus Casey* + Harpalus nigritarsus Sahlberg* + + + + Leistus ferruginosus Mannerheim + + - + + + Loricera decempunctata Eschscholtz* + + Nebria crassicornis V a n Dyke + + + + + + Notiophilus directus Casey + + + + + + Pterostichus adstrictus Eschscholtz* + + Pterostichus ecarinatus Hatch + + + + + Pterostichus herculeanus Mannerheim* + Pterostichus melanarius (Illiger)* + + + + + Pterostichus neobrunneus Lindroth + + + + + + Pterostichus pennsylvanicus LeConte + + + Pterostichus riparia (Dejean) + + + + • - + Scaphinotus angusticollis (Fischer von Waldheim) + + - + + + Scaphinotus marginatus (Fischer von Waldheim) + + + + + Scaphinotus relictus (Horn) + + • + + + • Syntomus americanus (Dejean) + Trachypachus holmbergi Mannerheim* l l iS l l l l III 111 ill ISiSlllI -Trechus chalybeus Dejean + + + + + + Trechus tenuiscapus Lindroth + + + + Total number of species 15 13 16 17 22 25 18 Tota l number of "new" species 0 1 3 5 9 11 Trends in flight capablities of species "new" to Sicamous Creek after harvesting can be observed in Table 2. Species that have more than one wing morph denoted in Table 2 are known to be either dimorphic or polymorphic. For many species, records of observed flight have not been made; however, the presence of fully formed wings and wing muscles is used to draw the conclusion that flight capabilities are complete (Lindroth, 1961-1969). For all species that exhibit more than one flight morph, the macropterous form was observed at Sicamous Creek in post-harvest sampling. 19 Table 2 Species attributes (Lindroth, 1961 -1969) W i n g Types European Species Species (* denotes "new" species, found only after harvesting) Apterous Brachypterous Macropterous Agonum metallescens (LeConte)* + Amara apricarius (Paykull)* + • Amara idahoana (Casey)* + Amara laevipennis Ki rby* + Bembidion breve Motschulskj + Bembidion grapei Gyllenhal* + + + Bembidion lampros (Herbst)* + + • Calathus advena (LeConte) + Harpalus animosus Casey* + Harpalus nigritarsus Sahlberg* + Leistus ferruginosus Mannerheim + + Loricera decempunctata Eschscholtz* + Nebria crassicornis Van Dyke + + Notiophilus directus Casey + + Pterostichus adstrictus Eschscholtz* + Pterostichus ecarinatus Hatch + Pterostichus herculean us + Mannerheim* Pterostichus melanarius (Illiger)* + + • Pterostichus neobrunneus Lindroth + Pterostichus pennsylvanicus LeConte + + Pterostichus riparia (Dejean) + Scaphinotus angusticollis (Fischer von Waldheim) + Scaphinotus marginatus (Fischer von Waldheim) + Scaphinotus relictus (Horn) + Syntomus americanus (Dejean) + + • Trachypachus holmbergi Mannerheim* + Trechus chalybeus Dejean + 20 Trechus tenuiscapus Lindroth + Seven species made up the "most common" group (shown in shading in Table 3), with over 1000 specimens of each collected (Table 3). Five of the "common" species are either brachypterous or apterous, showing adaptation to a less disturbed environment. Calathus advena and Nebria crassicornis are the only "common" species known to have macropterous morphs (Table 2), which were included in the specimens caught at Sicamous Creek. There were seven intermediately common species, having over 25 specimens in total. The other fourteen species were represented by 10 or fewer specimens, some represented by a single specimen. 21 Table 3: Total catch from pitfall traps at Sicamous Creek Study Site by treatment. Pre-treatment Post-treatment (pooled) (pooled) Species 1992-1993 1994- 1996 Uncut Con t ro l 25% 0.1 ha 1.0 ha 10 ha Agonum metallescens 0 0 0 0 4 0 Amara idahoana 0 . 0 0 1 2 6 Amara laevipennis 0 0 0 0 1 4 Amara apricaria 0 0 0 0 0 1 Bembidion breve 1 0 13 13 38 112 Bembidion grapei 0 0 0 1 2 3 Bembidion lampros 0 0 0 0 1 2 C 'alat hits advena 77 357 366 727 273 439 Harpalus animosus 0 0 0 0 0 1 Harpalus nigritarsus 0 0 2 2 8 46 Leistus ferruginosus 54 36 68 78 142 152 Loricera decempunctata 0 0 0 0 1 1 Nebria crassicornis 456 234 361 355 326 362 Notiophilus directus 2 1 1 2 1 3 Pterostichus adstrictus 0 0 3 0 9 15 Pterostichus ecarinatus 153 559 481 759 347 527 Pterostichus herculeanus 0 0 0 3 0 0 Pterostichus melanarius 0 1 2 2 4 1 Pterostichus neobrunneus 17 61 88 77 15 12 Pterostichus pennslyvanicus 1 1 0 0 0 3 Pterostichus riparia 658 321 609 907 805 1447 Scaphinotus angusticollis 2597 1838 1065 1719 1316 774 Scaphinotus marginatus 262 391 168 174 177 118 Scaphinotus relictus 80 82 46 57 69 36 Syntomus americanus 1 0 0 0 0 0 Trachypachus holmbergi 0 0 0 0 0 1 7 rechus chalyheus 349 16 179 110 277 262 Trechus tenuiscapus 64 0 15 0 1 6 TOTAL 4772 3898 3467 4987 3819 4334 22 Species Richness The results of rarefaction analysis of species richness show an overall increase in richness in logged sites. There were small increases and decreases in the pre-treatment control blocks, but owing to the high amount of variation, these differences were not statistically significant (Figure 4). 9 8 H 7 H 5 H 4 1991 1992 1993 Pre-treatment 1994 1995 1996 1997 Post-treatment 1998 Time Figure 4: Species richness for early August samples from control treatment blocks. Rarefaction estimated using a sample size of 45 specimens. 23 In the 0.1 (Figure 5) and 1.0 (Figure 6) treatments, post-treatment species richness showed remarkably different responses in the carabid assemblages. In the 0.1 hectare treatment, edge, clearcut, and forested rings were significantly different from each other the first year after harvest, with clearcut habitat fauna having the highest richness, edge habitat fauna having a median richness, and forested habitat fauna showing the lowest richness. However, faunal richness in these three habitats converge by the third post-treatment year (Figure 5). While these values do indicate a trend, they are not significantly different from pre-treatment values. 9 8 tn tn g 7 sz o * 6 tn CD O CD Q. CO clearcut i < edge , k '' < • < > -t forested i 1991 1992 1993 1994 Pre-treatment Time 1995 1996 1997 Post-treatment 1998 Figure 5: Species richness for early August samples from 0.1 hectare treatment blocks. Rarefaction estimated using a sample size of 35 specimens. 24 In the 1.0 hectare treatment, the first two years of post-treatment species richness values overlap, but diverge in the third year (Figure 6 ) . Clearcut samples showed a significant increase in species richness in the third year, whereas the edge and forested rings showed a non-significant trend towards a decrease in species richness, compared with pre-treatment values. co co 0 c o or CO CD "o 0) CL 00 14 12 H 1 0 H 9> 8 1991 1992 1993 Pre-treatment-1994 1995 clearcut Time' 1996 Post-treatment • 1997 1998 Figure 6: Species richness for early August samples from 1.0 hectare treatment blocks. Rarefaction estimated using a sample size of 60 specimens. 25 Post-treatment species richness in forest and edge habitat of 10 hectare treatment blocks decreased, but not significantly as compared to pre-treatment data (Figure 7). The clearcut richness showed a non-significant increase over the three years of post-treatment data. uj CD c .c o or tf) CD O CD Q . CO clearcut edge forested 1991 1992 1993 1994 Pre-treatment Time 1995 1996 1997 — Post-treatment 1998 Figure 7: Species richness for early August samples from 10 hectare treatment blocks. Rarefaction estimated using a sample size of 15 specimens. 2 6 The 25% Individual Tree Selection (I.T.S.) also showed a sudden rise in species richness the first year after harvest, but this was followed by a moderate reduction, resulting in a non-significant difference from pre-treatment values (Figure 8). c/) c/> CD C u a: CD O CU CL to 1991 1992 1993 1994 Pre-treatment— 1995 1996 1997 —Post-treatment Time Figure 8: Species richness for early August samples from 25% I.T.S. removal treatment blocks. Rarefaction estimated using a sample size of 210 specimens. 1998 Whittaker Plots The analysis of species evenness within each type of canopy cover for different treatments showed shifts in dominance of a few species. This pattern of dominance is not apparent in the analysis of species richness, and can be masked by other factors in heterogeneity indices such as the Shannon-Weiner and Simpson's, which analyze both the evenness and the abundance of species. Therefore, Whittaker plots of rank versus percent abundance were graphed to provide a visual example of community structure. 27 Whittaker plots for control blocks show that there was variation in pre-treatment years (Figure 9). Moderately abundant species and some of the rarer species dropped in adundance in the last year of pretreatment data, but variation between the three years of pre-treatment data is minimal (Figure 9). Figure 9: Whittaker plots of rank/abundance for pre-treatment control data. Percent abundance of each species is plotted on a logarithmic scale against species rank, ordered from most to least abundant. 28 Post-treatment Whittaker plots for control blocks show a dominance structure similar to that shown in pre-treatment plots, with many species in the intermediate abundance group and little variation over the three years of pre-treatment collection (Figure 10) . 0 1 2 3 4 5 6 7 8 9 10 11 12 R a n k Figure 10: Whittaker plots of rank/abundance for post-treatment control data. Percent abundance of each species is plotted on a logarithmic scale against species rank, ordered from most to least abundant. 100 • 1995 -m- • 1996 1997 0.1 29 Whittaker plots for pre-treatment 0.1 hectare blocks show little variation from the distribution seen in control blocks, with many intermediately abundant species (Figure 11). However, post-treatment analyses show that there were different responses within each canopy cover (Figures 12 to 14). 100 0) o c CO T J c JO < R a n k Figure 11: Whittaker plots of rank/abundance for 0.1 hectare blocks pre-treatment. Percent abundance of each species is plotted on a logarithmic scale against species rank, ordered from most to least abundant. 30 Carabid fauna in forested habitat of the 0.1 hectare treatment blocks showed decrease in intermediately abundant species, resulting in a steeper drop from most abundant to second-most abundant (Figure 12). 1 0 0 CD O c cn •o c < Figure 12: Whittaker plots of rank/abundance for forested habitat in 0 . 1 hectare blocks post-treatment. Percent abundance of each species is plotted on a logarithmic scale against species rank, ordered from most to least abundant. 31 Carabid fauna of edge habitat in 0.1 ha post-treatment did not show much chang from the pre-treatment distribution and retained a large group of species in the intermediately abundant class (Figure 13). Figure 13: Whittaker plots of rank/abundance for edge habitat in 0.1 hectare blocks post-treatment. Percent abundance of each species is plotted on a logarithmic scale against species rank, ordered from most to least abundant. 32 The carabid fauna of the clearcut community of 0.1 hectare post-treatment blocks showed a very different response, maintaining the top four most abundant species, but with a substantial drop in the lower half of the intermediate abundance class (Figure 14). Within the top four most abundant species, there is very little variation in percent abundance, indicating nearly equal dominance. Figure 14: Whittaker plots of rank/abundance for clearcut habitat in 0.1 hectare blocks post-treatment. Percent abundance of each species is plotted on a logarithmic scale against species rank, ordered from most to least abundant. 33 The 1.0 hectare treatments showed results similar to those shown by 0.1 hectare treatments. Pre-treatment carabid abundance for all years also show a large number of intermediately abundant species (Figure 15). 100 CD O c CD C < Figure 15: Whittaker plots of rank/abundance for 1.0 hectare blocks pre-treatment. Percent abundance of each species is plotted on a logarithmic scale against species rank, ordered from most to least abundant. 34 The carabid fauna of forested and edge habitats in 1.0 hectare post-treatment blocks exhibited a great change from pre-treatment distributions, with substantial drops intermediately abundant species (Figure 16 and 17). The forested habitat fauna demonstrated a dominance structure broken up into one or two dominant species, with two groups of species in intermediate and rarer abundances (Figure 16). 100 • 1995 -m- • 1996 1997 1 H o 2 3 4 5 6 7 8 9 10 11 12 R a n k Figure 16: Whittaker plots of rank/abundance for forested habitat in 1.0 hectare blocks post-treatment. Percent abundance of each species is plotted on a logarithmic scale against species rank, ordered from most to least abundant. 35 In the edge habitat fauna of the 1.0 hectare post-treatment blocks (Figure 17), there was less of a drop in the abundance of rarer species, in comparison with the forested habitat (Figure 16). The most dominant species has a much higher abundance than the intermediately group following it. 100 cu o c ro c < Figure 17: Whittaker plots of rank/abundance for edge habitat in 1.0 hectare blocks post-treatment. Percent abundance of each species is plotted on a logarithmic scale against species rank, ordered from most to least abundant. 36 In fauna of the clearcut habitat of the 1.0 hectare treatment, there is a strong resemblance to the dominance structure in the pre-treatment data, with a much more gradual decrease in dominance from upper to lower ranks (Figure 18). 1 0 0 O c to T3 C < 1 0 A R a n k Figure 18: Whittaker plots.of rank/abundance for clearcut habitat in 1 . 0 hectare blocks post-treatment. Percent abundance of each species is plotted on a logarithmic scale against species rank, ordered from most to least abundant 3 7 The 10 hectare treatments also did not show much change in the pre-treatment years, closely resembling the plots for the other treatments (Figure 19). 1 0 0 o c CO "O C 3 < Figure 19: Whittaker plots of rank/abundance for 1 0 hectare blocks pre-treatment. Percent abundance of each species is plotted on a logarithmic scale against species rank, ordered from most to least abundant. 38 After logging in the study site, abundance curves changed little from their initial distributions. However, third year post-treatment sampling in forested and edge habitats showed a change in dominance structure (Figures 20 and 21). In carabid fauna of the forested habitat there was a dramatic steepening of the rank abundance curve, owing to a severe drop in the number of intermediately abundant and rarer species (Figure 20). 100 - • - 1 9 9 5 - • - • 1996 1997 0 2 3 4 5 6 7 8 R a n k Figure 20: Whittaker plots of rank/abundance for forested habitat in 10 hectare blocks post-treatment. Percent abundance for each species is plotted on a logarithmic scale against species rank, ordered from most to least abundant. 3 9 In the edge habitat of the 10 hectare post-treatment blocks, both intermediate and rare species dropped in abundance in the third year of post-harvest sampling, showing a very different distribution of species from the first and second year of post-harvest sampling (Figure 21). 1 0 0 cu o c CO T J c .a < Figure 21 : Whittaker plots of rank/abundance for edge habitat in 1 0 hectare blocks post-treatment. Percent abundance of each species is plotted on a logarithmic scale against species rank, ordered from most to least abundant. 40 In fauna of the clearcut habitat of 10 hectare treatments, there was little difference from the pre-treatment data, except for an increase in the number of species recorded (Figure 22). Figure 22: Whittaker plots of rank/abundance for clearcut habitat in 10 hectare blocks post-treatment. Percent abundance of each species is plotted on a logarithmic scale against species rank, ordered from most to least abundant. The 25 % Individual Tree Selection (I.T.S.) treatment showed almost no variation from control distributions from pre-treatment (Figure 23) to post-treatment sampling (Figure 24). 41 100 CD o c ro "D £Z < Figure 23: Whittaker plots of rank/abundance for pre-treatment 25% ITS blocks. Percent abundance of each species is plotted on a logarithmic scale against species rank, ordered from most to least abundant. 100 cu o c ro c < 13 14 Figure 24: Whittaker plots of rank abundance for post-treatment 25% ITS blocks. Percent abundance of each species is plotted on a logarithmic scale against species rank, ordered from most to least abundant. 42 Heterogeneity Indices The Shannon-Wiener Index, a measure of entropy or randomness within a series of numbers, emphasizes changes that occur in rarer species within an assemblage. This index provides a numerical assessment of changes that occur in the higher numbered ranks of species in the Whittaker plots. These measures provide contrast when compared to the Simpson's Index which measures diversity and richness of more common species. In control treatments, there is a great deal of variation in diversity from pre-treatment to post-treatment years in both the Shannon-Wiener Index results (Figure 25) and the Simpson's Index (Figure 26). The most notable result of the diversity indices is the similarity in trends between the two sets of results. Although the Simpson's Index does show less dramatic results (Figure 26), there is remarkably little difference between the responses of rare and common species diversities. 43 Time Figure 25: Shannon-Wiener Diversity Index values for control treatment. Time Figure 26: Simpson Index values for control treatment 44 Carabid fauna in 0.1 hectare treatments exhibited a response in heterogeneity indices similar to species richness changes. A comparison of Figures 27 and 28 contrasts the magnitude of change in different abundance ranks. The Shannon-Wiener index values for the 0.1 hectare treatment show interesting trends (Figure 27). The fauna collected in the clearcut habitat of 0.1 hectare treatments showed an influx of new, less common species after logging, with no change in heterogeneity after three years of post-harvest sampling. Forested habitat fauna showed a significant rise in diversity of rare species after the third year of post-harvest sampling, indicating a delayed effect of logging manipulations. The edge habitat carabid fauna showed some decline over the three postharvest years but no change in the degree of decline. Carabid biodiversity in the Simpson's Index for the 0.1 hectare treatment (Figure 28) showed much less dramatic change in the more common species after logging in edge habitat. Trends of decline and increase in the edge and forested habitat fauna are similar to those illustrated by the Shannon-Wiener Index. Clearcut fauna showed a bit more variation, declining in the second year after harvest, but rebounding to levels similar to initial post-harvest sampling period. 45 Figure 26: Simpson Index values for 0.1 hectare treatment. 46 The comparison of results for the 1.0 hectare treatment show more variation in the effect of logging on rare versus common species. The Shannon-Wiener Index indicates a continued effect of logging in edge and forested habitats, as the diversity continues to decline (Figure 29). Clearcut habitat fauna do not show a continued effect of logging on the rare species from the second to third year of post-treatment sampling. Comparison of these results with Simpson's Index results (Figure 30) indicates the impact of 1.0 hectare clearcuts is greater on rare species than on common ones. In edge arid forested habitats, impacts on common species levels off after three years, however, the reverse is true in clearcuts (Figure 30). In clearcut habitats, more common species begin to decline in the third year, indicating that impacts of tree removal are not fully realized yet. 47 2.2 1.0 -I 1 1 1 1 1 r 1991 1992 1993 1994 1995 1996 1997 1998 Pre-treatment Time Post-treatment Figure 29: Shannon-Wiener Diversity Index values for 1.0 hectare treatment. Figure 30: Simpson Index values for 1.0 hectare treatment. 48 The 10 hectare treatments show the most dramatic differences between common versus rarer species. The rarer species show very little change after logging, with only a moderate spread between diversities of all habitat types, even after the third year of post-treatment sampling (Figure 31). There is an influx of common species in edge and forested habitat, which then steeply declines in the second and third year post-harvest (Figure 32). In the clearcut habitat, there is little change until the second post-harvest year, when the diversity of more common species dramatically rises. In comparison with trends in Shannon-Wiener results, the impacts of 10 hectare treatment on the more common species is quite marked. 49 Figure 31: Shannon-Wiener Diversity Index values for 10 hectare treatment. 50 Results of the heterogeneity indices for the 25% Individual Tree Selection treatment are similar for both the Shannon-Wiener and Simpson's Indices, showing that this treatment had effects on all species, regardless of how common or rare they were. The first year post-treatment for both show a large increase in diversity, followed by a moderate drop in the second year, which is compensated for in the third year with a slight increase (Figures 33 and 34). While post-treatment trends are not greater than those seen in pre-treatment data, they are opposite to trends in control block data (Figures 25 and 26). 51 1.4 H 1991 1992 1993 1994 1995 1996 1997 1998 Pre-treatment Time • Post-treatment Figure 33: Shannon-Wiener Diversity Index values for 25% ITS treatment. 1991 1992 1993 1994 1995 1996 1997 1998 Pre-treatment -r- Post-treatment Time Figure 34: Simpson Index values for 25% ITS treatment 52 Intraspecific Comparison Clearcut size Comparison of number of individuals per trap 0.1, 1.0 and 10 hectare treatments was done for traps in clearcuts only, to isolate the effect of larger opening sizes. Significant results for three species, namely, Harpalus nigritarsus, Bembidion breve, and Pterostichus adstrictus, were obtained in the A N O V A . Means of these species are presented in Figure 35 for comparison, along with A N O V A results contained in the caption. C L CO 0.18 0.16 0.14 0.12 -0.10 -cu a. 0.08 tz cu 0.06 0.04 0.02 0.00 H Harpalus nigritarsus Bembidion breve Pterostichus adstrictus 0.1 1.0 10 hectare hectare hectare P o s t - T r e a t m e n t Figure 35: Mean number of Harpalus nigritarsus, Bembidion breve, and Pterostichus adstrictus per trap for pooled post-treatment data in 0.1, 1.0, and 10 hectare treatment plots. ANOVA results: F (crit.)= 3.68 Harpalus nigritarsus F- 4.45 Bembidion breve F= 13.35 Pterostichus adstrictus F= 3.56 53 2 5 % I T S and 0.1 hectare removals Comparison between the 25% I.T.S. and 0.1 hectare removal treatments was done using data from all traps in each treatment; because the comparison is between these treatments as a whole, pooling data from traps in all habitat types is necessary. To simplify the analysis, post-treatment data were used. Only Scaphinotus angusticollis showed any significance in A N O V A results in comparison of 25% I.T.S. removal and 0.1 hectare clearcut treatments. Therefore, only means for S. angusticollis results are presented (Figure 36). 3 CD CL c CO CD 1 H o 0.1 hectare 25% ITS P o s t - T r e a t m e n t F igure 36: Mean number of Scaphinotus angusticollis per trap in 0.1 hectare and 25% ITS removal for pooled post-treatment data. ANOVA results: F (crit.)=4.96 F=5.78 54 Forest M a r g i n Comparison between treatments for the effect of width of the forest margin was done by calculating the mean number of individual species per trap in each treatment using traps in the forested habitat only. Although sampling effort was not equal in the forested habitat for all treatments, any obvious trends should be apparent in this analysis. However, no significant differences in mean number of individuals per trap were detected in ANOVA calculations (Figure 37). C L CO C L 1 c CD CD o H -1 H Scaphinotus angusticollis Nebria crassicornis Calathus advena 0.1 hectare 1.0 hectare 10 hectare Post-treatment-Figure 37: Mean number of Scaphinotus angusticollis, Nebria crassicornis, and Calathus advena per trap for pooled post-treatment data. ANOVA results: F (crit.)= 3.98 Scaphinotus angusticollis F= 1.14 Nebria crassicornis F= 0.49 Calathus advena F=2.12 55 Total Treatment Responses Individual species showed slight responses to treatments as a whole. Responses of individual species are shown in Figure 38. The A N O V A results did not detect any significant differences in species responses to treatments. However, Scaphinotus angusticollis and Leistus ferruginosus do come close to the critical value for the F statistic. The responses of Scaphinotus angusticollis and Leistus ferruginosus are somewhat different, with S. angusticollis showing a decline in numbers with increasing clearcut size and L. ferruginosus showing a slight increase with clearcut sizes. Q _ 03 CU Q _ C CO cu 10 H 8 6 H 4 2 o H -2 -4 Pterostichus riparia Leistus ferruginosus Scaphinotus marginatus Scaphinotus angusticollis Control 25% ITS 0.1 1.0 hectare hectare Post-treatment — 10 hectare Figure 38: Mean number of Pterostichus riparia, Leistus ferruginosus, Scaphinotus marginatus, and Scaphinotus angusticollis per trap for pooled post-treatment data. ANOVA results: F (crit.)= 3.22 Pterostichus riparia F= 0.74 Leistus ferruginosus F= 2.49 Scaphinotus marginatus F=0.12 Scaphinotus angusticollis F= 2.55 56 Discussion The number of species observed at Sicamous Creek was similar to other studies conducted in the E S S F biogeoclimatic zone (Lemieux, 1998; McDowe l l , 1998). The species found to be most abundant in this study (e.g. Scaphinotus angusticollis) were also the most common in these studies as well (Lemieux, 1998; McDowel l , 1998). Studies of mature forests in other biogeoclimatic zones have also found a comparable numbers of species (Duchesne and McAlp ine , 1993; Craig, 1995). N o new species were recorded in this study. However, a variant of Pterostichus ecarinatus was found in the population with two mid-lateral seta on its pronotum rather than the normal, single setae. Some species (e.g. Pterostichus pennsylvanicus and Bembidion breve), which are known to be associated with open or disturbed areas like clearcuts and large natural openings and macropterous (Lindroth, 1961-1969), were observed in pre-treatment samples, although found in low numbers (Table 3). This suggests that the study site and/or a neighbouring areas had levels of natural disturbance that would support small populations of these beetles or attract dispersers from other areas. The proximity of a "source" population of xerophilous species is evident in this study. Establishment of these species in disturbed habitats of Sicamous Creek may be an ongoing process merely accelerated by logging as indicated by the higher total catch for species like Pterostichus pennsylvanicus, Bembidion breve, and Notiophilous directus in post-treatment data collection (Table 3). 57 Scale of Observation Landscapes play an important role in both forest ecology and management. Forest management occurs first at the landscape level, the most operable unit to work with. Examination and management of smaller clearcuts on the landscape level is important for two reasons. Firstly, there is a mathematical relationship between forest core habitat, which is "insulated" from microclimatic change (see Chen et al, 1995), and the sizes of clearcuts. A s the size of clearcutting is reduced below 20 hectares and the volume of timber removed remains constant, the amount of forest core habitat drops off quickly (Gustafson and Crowe, 1994). Secondly, the creation of habitat reserves within a managed environment also depends heavily on the landscape level of observation, which is the scale that most small and medium-range creatures "operate" on (Franklin, 1993). The establishment of patterns at the landscape level is important on a temporal scale as well . Studies comparing dispersed versus aggregated logging patterns by Wal l in et al. (1994) show that once patterns of succession are established at the landscape level, they cannot be changed, even with drastic modifications in management planning. Landscape ecology is very important to the biology of insects. The significance of structures like roads and railways within landscapes has been suggested as barriers to dispersal for carabid beetles and some species of spiders (Mader, 1986; Mader et al, 1990). Furthermore, landscape level disturbance by human influence is more wide-scale and permanent than the effects of weather cycles on insect populations (Samways, 1989). This emphasizes the results of more mathematical studies of diversity measurements which also recommend analysis at the landscape level (Halffter, 1998). 58 Species Richness The results of rarefaction analysis highlight changes that occurred in the number of species after logging. These results are similar to other studies which also recorded an influx of new species after logging (Lenski, 1982; Niemela and Halme, 1992; Niemela et al, 1993; Duchesne and McAlp ine , 1994; Spence et al, 1996) and that this increased richness is perpetuated throughout early serai stages of a forest (Spence et al, 1996). Control blocks at Sicamous Creek did not exhibit much change after logging, indicating that the influx of new species did not extend substantially into control blocks. The size of these control blocks must therefore have been large enough to isolate them from the influences of treatments around them. Results of other treatment blocks show some very significant changes, however. In 0.1 hectare plots, there was a very strong initial difference in species richness between clearcut, forested, and edge habitats, reflecting a difference in the amount of disturbance created by logging. However, as sampling proceeded over three year of post-harvest data collection, there was convergence of species richness in all three habitats. The width of forest margin around the clearcuts in the 0.1 hectare treatments may have been more permeable to species that were introduced after logging, leading to a homogenization of habitats in the 0.1 hectare treatments and similar richness values as compared to 1.0 hectare treatments. These results are consistent with findings of a study on forest fragmentation in historically disturbed forests in Finland where smaller patches of forest were found to have similar species richness to the surrounding open areas (Niemela et al, 1993). This suggests that initial changes in the species richness of 0.1 hectare clearcuts seen in this study may result in a permanent alteration of the carabid assemblage. 59 In the 1.0 hectare blocks, an opposite reaction to logging was observed. While the carabid fauna in forest, edge, and clearcut habitats showed similar initial responses, richness diverged over the three post-treatment years. These results indicate that new species continued to colonize clearcuts following harvesting, but that forested and edge habitat did not have a similar influx of "new" species. One reason for this response may be that the remaining forested habitat offers a more stable environment owing to the increased forest interior habitat as compared to 0.1 hectare treatments. A lack of significant response by species found in forested habitat to new species' introduction is consistent with findings of a study in semi-agricultural settings near Edmonton, Alberta (Niemela and Spence, 1991). The influx of Pterostichus melanarius, an introduced European species commonly associated with disturbed habitats, was shown to not impact the richness of previously existing species in areas surrounding farmer's fields and within semi-urbanized habitats (Niemela and Spence, 1991). The lack of response by species in the 1.0 hectare habitats may indicate that enough suitable habitat was preserved to allow carabid populations to remain stable. Another finding in the results indicates that previous theories on carabid species richness and edge effects may be too narrow in focus. Edge habitat in all treatments more closely mirrored changes in forest habitat than changes that occurred in clearcut habitat. The species composition of edge habitats was therefore subject to changes that were more similar to those experienced by forested habitat fauna than to those experienced by clearcut habitat fauna. Perhaps forest-preferring species use edge habitat and also contribute to species richness of this habitat. This contradicts findings of other studies which suggest that edge habitat is much more diverse in its carabid fauna (Niemela and Halme, 1992; Baguette and Gerard, 1993). Since these studies were conducted after logging had occurred, there may have been a decline in the 60 "original" species that was not recorded, before edge-preferring species took over and increased species richness along the edges of the forest. Changes in species richness in the 10 hectare treatments reflected some of the changes from the 1.0 hectare treatments. Species richness in edge and forest habitats mirrored one another closely, suggesting that there were similar factors, determining which carabids may be found in these areas. Ten hectare treatments have the thickest forest margins of the three treatments. However, a decreasing trend in species richness over three years of post-treatment sampling in edge and forest habitat indicates that there are continuing and escalating detrimental effects to carabid species richness after harvesting, similar to 1.0 hectare treatments. Clearcut sampling showed that there is a limit to the number of species that can colonize this habitat successfully, as species richness did level off after three years. The environment of a 10 hectare clearcut may be unsuitable for some carabids and limit the number of species that can use this new habitat. It is difficult to compare the results of this study directly with those of previous studies. Differences in treatments are diverse, and as stated previously, no studies have both pre- and post-treatment data for the same population of carabids. In a general sense, species richness results showed expected increases in clearcut habitat in this study, and this is consistent with findings of other studies on logging and different types of disturbance. The decrease in species richness of edge habitat in the 1.0 and 10 hectare clearcut treatments may be attributed to a decrease in the habitat use by some forest species before disturbance-specialist species can establish their populations. 61 Species Evenness As habitat becomes more disturbed, opportunities for new species to move in become available and preemption of resources by new species may occur (Southwood, 1978). The shape of the line formed by graphing species' relative (percent) abundance versus rank reveals the amount of competition between species (Magurran, 1988). Where there are few species dominating a large amount of the resources available, a steeper Whittaker plot will result as niche preemption prevents other species from maintaining a larger proportion of the community's numbers (Southwood, 1978). As the slope of Whittaker plots decreases, so does the amount of competition within the community, resulting in an almost even distribution of species that are not using the same resources within the community (Southwood, 1978). Trends in species dominance shifts within the carabid community showed some similarities across the three treatments. Forested habitat carabid fauna in all treatments show that there was a change in dominance of middle, or moderately abundant, ranks. Edge habitat fauna showed more effect on the most dominant species, creating a more step-wise Whittaker plot. Clearcut habitat fauna, however, showed little change in trend from the pre-harvest dominance structure, although the slope of Whittaker plots for this habitat tend to be less steep. In both forested and clearcut habitats, a few species occupied a dominant role, indicating that competition for resources may be a determining factor to species abundance. Evenness in edge habitats, however, suggests less competition for resources. This may indicate that conditions are prohibitive of populations establishing and dominating this habitat, giving equal opportunity to all species. 62 Heterogeneity Indices Comparison of trends in Shannon-Wiener and Simpson's Indices show varying effects on rare and common species. The higher diversity observed in clearcuts as compared to the surrounding forested habitats in this study is consistent with findings in other studies (Craig, 1995; M c D o w e l l , 1998). However, treatment-level examination does indicate some differences between findings of this study with those of others. Although no heterogeneity index values were given, Lemieux's study on carabid beetles in the E S S F biogeoclimatic zone near Smithers, B C (1998) stated that change within the most common species was the source of differences between patch cut and clearcut areas. This finding is not supported in all cases by my study. Rare species had greater effect on heterogeneity indices in 0.1 and 1.0 treatments, but more common species created greater change in diversity indices of 10 hectare treatments. This difference in findings may be attributable to the scale of treatment, as 10 hectare clearcut treatments are more comparable with logging manipulations in Lemieux's study. A n unexpected result of heterogeneity index analysis in my research was the indication that there are cumulative and varying effects to clearcutting that are not fully realized even after three years of post-treatment collection. A delayed response to environmental change like this may have many causes. Carabid beetles have been observed to live for a surprising number of years at higher altitudes (Butterfield, 1996). This may be owing to a shortened summer season which results in a shortened period of growth for larvae and lack of prey availability for adults and larvae alike (Butterfield, 1996). If a carabid population were to die off slowly through attrition, the response would look somewhat like that of clearcut habitats in this study. Not enough is known about the habitat and prey requirements of larval carabids to conclude i f this is 63 the case. Further research into the habitat and prey requirements of carabid beetles is crucial to our understanding of their populations' responses. Intraspecific Comparisons Clearcut sizes Only species "new" to Sicamous Creek (e.g. Bembidion breve) showed significant and positive responses to larger clearcuts (Figure 35). This increase could have occurred for a number of reasons. Larger clearcuts may present a larger target for species that are dispersing by flight, and therefore collected larger numbers of "new" species. With the exception of Pterostichus herculeanus, flight capability was found in all species new to Sicamous Creek, suggesting that flight is an important mechanism of dispersal to this site. However, Spence and Spence (1988) have expressed some doubt as to the importance of flight as a primary means of dispersal in carabids (see Thiele, 1977), citing the influence of human invasion of wilderness as a more likely means of dispersal. Further evidence for the use of flight in dispersal by carabids is needed to clarify this issue. Despite wide variation in clearcut sizes, species that were prominent in pre-harvest collections did not show significant change in their usage of clearcuts, as shown in the abundance of individual species trapped. This indicates that the smaller clearcut patches in forested habitat were not used more than large clearcuts by forest species, as might be expected in species which are predominately flightless and therefore must rely on walking as a means of dispersal (den Boer, 1980). A study on the visual capabilities of a flightless carabid indicates that they should be able to orient to a forest horizon no more than 85 m away (Weseloh, 1997), and therefore smaller clearcuts should pose less of a barrier to dispersal. However, there was no significant increase in habitat use by carabids in smaller clearcuts compared to large patches. This may be 64 due to decreased visual capabilities of these carabids, which may reflect a lack of evolutionary selection for avoidance of open areas. Forest Fragmentation Part A Selective Logging versus Small Clearcuts Only Scaphinotus angusticollis showed any significant difference in preference between 25% I.T.S. treatments and 0.1 hectare clearcuts. The narrow margins of forest around the tiny, 0.1 hectare clearcuts must therefore provide some minimal refuge from the disturbed habitat of clearcuts, despite their narrow width. A s the most sensitive forest species in this study, the response of Scaphinotus angusticollis is an important indication that microclimatic conditions vary between individual tree selection and clearcuts. These are important differences that w i l l determine the survival of a species in a harvested area. Part B Forest Margin Thickness In comparisons of forest margins, no substantial differences were detected for any species, although Scaphinotus angusticollis did have the highest " F " value in the A N O V A results from forest samples, almost showing a significant change. Lack of significant results for this comparison may be partially attributable to unequal sampling of forest habitat in the 10 hectare treatments. Only one ring of pitfall traps was placed in forested habitat of 10 hectare treatments, possibly leading to an underestimation of species responses to wider margins, found in the 10 hectare treatments. Highlighting Scaphinotus angusticollis as a sensitive species is not surprising, given their ecology. A l l Scaphinotus are specially adapted to feeding on snails (Lindroth, 1961-1969; Digweed, 1993) and have been shown to decrease in diversity with clearcutting (Lenski, 1982). 65 Therefore, it is not surprising that the abundance of S. angusticollis dropped in clearcut areas at Sicamous Creek. Total Treatment Responses Results of pooled habitat comparisons between treatments did not show any significant difference in responses of species. In comparison with results from richness, evenness, and diversity analyses, there was surprisingly little change from treatment to treatment, although Scaphinotus angusticollis and Leistus ferruginosus did show almost significant trends. Unfortunately, many species' abundances were too low to be analyzed by A N O V A and might have shown some response i f greater numbers were caught. On the whole, treatments did not show significant variation for individual species. 66 Conclusion The experimental design used in this study was effective in detecting new information on changes in carabid beetle assemblages under different harvesting regimes. Species richness and evenness of the carabid community showed similar responses in clearcut and forested habitat fauna. However, edge habitat bore little resemblance to the species evenness of forested and clearcut habitat within treatments, species richness and diversity indices were similar to those of forested habitat fauna. In all three clearcutting treatments, edge habitat represented a unique community that may be subject to very different selective pressures than forested and clearcut habitats. These findings may not have been discovered in previous studies on carabid beetles because pre-treatment data were not available for comparison. Scaphinotus angusticollis was the most sensitive species to habitat alteration. This is probably due to two factors: it is the most abundant species in the study site in both pre-treatment and post-treatment sampling, and it is known to have preference for forested habitats (Lindroth, 1961-1969; Craig, 1995; Lemieux, 1998; McDowel l , 1998). Scaphinotus angusticollis'' reactions to change in environment is consistent with observations in other studies (Lenski, 1982; Craig, 1995; Lemieux, 1998) which found this species to prefer forested habitat, which limits their success in clearcut habitats. The higher abundance of S. angusticollis, compared to other species may have made results statistically clearer, as this tends to give better results in A N O V A (Zar, 1984). However, no one species can illustrate all o f the changes that occur in carabids as a whole, and caution should be used before using a single species to diagnose changes for an entire group. 67 Literature Cited Asquith, A . , J .D. Lattin, and A . R . Moldenke. 1990. Arthropods, the Invisible Diversity. The Northwest Environmental Journal 6(2): 404-405. Baguette, M . and S. Gerard. 1993. Effects of spruce plantations on carabid beetles in southern Belgium. Pedobiolosia 37: 129-140. Boyle, T.J .B. 1991. Biodiversity of Canadian Forests: Current status and future challenges. The Forestry Chronicles 68(4): 444-453. Butterfield, J. 1996. Carabid life-cycle strategies and climate change: a study on an altitude transect. Ecological Entomology 21: 9-16. Chen, J., J.F. Franklin, and T . A . Spies. 1995. Growing-Season Microclimatic Gradients from Clearcut Edges into Old-Growth Douglas-Fir Forests. Ecological Applications 5(1): 74-86. Craig, K . 1995. Variation in Carabid Community Structure Associated with Coastal Douglas-Fir Forest Successional Stages. M.Sc . Thesis, University of British Columbia. Pp. i i to 56. Day K . R . and J. Carthy. 1988. Changes in Carabid Beetle Communities Accompanying a Rotation of Sitka Spruce. Agriculture, Ecosystems, and Environment 24: 407-415. den Boer, P.J. 1970. On the Significance of Dispersal Power for Populations of Carabid Beetles (Coleoptera: Carabidae). Oecologia 4:1-28. den Boer, P.J. 1986. Carabids as Objects of Study. In Carabid Beetles: Their Adaptations and Dynamics. Gustav Fischer: New York. Pp. 539-551. Digweed, S.C. 1993. Selection of Terrestrial Gastropod Prey by Chychrine and Pterostichine Ground Beetles (Coleoptera: Carabidae). Canadian Entomologist 125(3): 436-472. Duchesne, L . C . and R.S. MacAlpine. 1994. Using Carabid Beetles (Coleoptera: Carabidae) as a Means to Investigate the Effect of Forestry Practices on Soil Diversity. Forestry Canada, PNF1Technical Reports, Pp. 10. Fisher, B . L . 1998. Insect Behavior and Ecology in Conservation: Preserving Functional Species Interactions. Annals of the Entomological Society of America 91(2): 155-158. Forest Practices Code Biodiversity Handbook. 1995. British Columbia Ministry of Forests: Victoria, B . C . Franklin, J.F. 1993. Preserving Biodiversity: Species. Ecosystems, or Landscapes?. Ecological Applications 3(2): 202-205. 68 Gustafson, E .J . and T.R. Crow. 1994. Modeling the effects of forest harvesting on landscape structure and the spatial distribution of cowbird brood parasitism. Landscape Ecology 9(4): 237-248. Haack, R . A . and J.W. Byler. 1993. Insects and Pathogens: Regulators of Forest Ecosystems. Journal of Forestry 91: 32-37. Haila, Y . , I .K. Hanski, J. Niemela, P.Punttila, S. Raivio, and H . Tukia. 1994. Forestry and the boreal fauna: matching management with natural forest dynamics. Annates Zoologici Fennici31: 187-202. Halffter, G . 1998. A Strategy for Measuring Landscape Biodiversity. Biology International 36: 3-17. Halme, E . and J. Niemela. 1993. Carabid beetles in fragments of coniferous forest. Annales Zoologici Fennici 30: 17-30. Hammond, H . 1993. Forest Practices: Putting holistic forest use into practice. In Touch Wood: B . C . Forests at the Crossroads. K . Drushka, B . Nixon, R. Travers (eds.). Harbour Publishing: Madeira Park, B . C . Pp. 96-136. Harris, L . D . 1988. Edge Effects and Conservation of Biotic Diversity. Conservation Biology 2(4): 330-332. Heijerman, T . H . and H . Turin. 1994. Towards a method for Biological assesmant of habitat quality using carabid samples (Coleoptera, Carabidae). In Carabid beetles: Ecology and Evolution. Desender et al (eds.). Kluer Academic: Netherlands. Pp. 305-312. Holdstedt, C. and A . Vyse. 1997. Sicamous Creek Silivicultural Systems Project: Workshop Proceedings. British Columbia Ministry of Forests Working Paper Number 24, Kamloops, B . C . Holliday, N . J . 1991. Species responses of carabid beetles (Coleoptera. Carabidae) during post-fire regeneration of boreal forest. Canadian Entomologist 123:1369-1389. Huggard, D . and W . Klenner. 1995. The effects of forest management on shrews and ground-dwelling arthropods: working plan. Wildlife Ecology Research, Forest Sciences Section. Ministry of Forests. Kamloops, B . C . Jennings, D.T. , M . W . Houseweart, and G . A . Dunn. 1986. Carabid Beetles (Coleoptera: Carabidae) Associated with Strip Clearcut andDense Spruce-Fir Forests of Maine. The Coleopterists Bulletin 40(3): 251-263. Kevan, D . K . M c E . 1962. Soil Animals. Witherby: London. Krebs, C.J . 1989. Ecological Methodology. Harper Collins: N e w York. 69 Lattin, J.D. 1993. Arthropod Diversity and Conservation in Old-Growth Northwest Forests. American Zoologist 33: 578-587. Lemieux, J.P. 1998. Species and Assemblage Responses of Carabidae (Coleoptera) to Forest Harvesting: Contrasting Clearcut and Patch Retention Removals in High-Elevation Forests of Central British Columbia. Master's Thesis, University of Northern British Columbia. Pp. ii-123. Lenski, R.E. 1982. The impact of forest cutting on the diversity of ground beetles (Coleoptera: Carabidae) in the southern Appalachians. Ecological Entomology 7: 385-390. Lindroth, C H . 1961-1969. The Ground Beetles of Canada and Alaska. Opuscula Entomologica, Supplementum XX-XXXIV. Pp. 1-1192. McDowell, J.K. 1998. Response of Carabid Species and Assemblages to Forest Practices of Britich Columbia in Englemann Spruce-Subalpine Fire and Interior Cedar-Hemlock Forests. Master's Thesis, University of British Columbia. Pp. ii-106. McNeely, J.A. 1994. Lessons from the past:: forests and biodiversity. Biodiversity and Conservation 3: 3-20. Mader, H.J. 1984. Animal Habitat Isolation by Roads and Agricultural Fields. Biological Conservation 29: 81-96. Mader, H.J., C. Schell, and P. Kornacker. 1990. Linear Barriers to Arthropod Movements in the Landscape. Biological Conservation 54: 209-222. Magurran, A .E . 1988. Ecological Diveristy and its Measurement. Princeton University Press: Princeton, N.J. Meidinger, D. and J. Pojar. 1991. Ecosystems of British Columbia. Special Report, Series Number 6. B.C. Ministry of Forests: Victoria, B.C. National Forestry Database. 1998. Site manager: Suzanne Gailloux (CFS Industry, Economics and Program Branch), http://www.nrcan.gc.ca/cfs/proj/iepb/nfdp/frames_e.html Last updated: Oct. 15, 1998 Niemela, J. and E. Halme. 1992. Habitat associations of carbid beetles in fields and forests on the Aland Islands. SW Finland. Ecography 15: 3-11. Niemela, J. and J.R. Spence. 1991. Distribution and abundance of an exotic ground-beetle (Carabidae): a test of community impact. Oikos 62: 351-359. Niemela, J.K. and J.R. Spence. 1994. Distribution of forest dwelling carabids (Coleoptera): spatial scale and the concept of communities. Ecography 17: 166-175. 70 Niemela, J., Langor, D . and J.R. Spence. 1993. Effects of Clear-cut Harvesting on Boreal Ground-Beetle assemblages (Coleoptera: Carabidae) in Western Canada. Conservation Biology 7(3): 551-561. Oliver, I. and A . J . Beattie. 1996. Designing a Cost-effective Invertebrate Survey: a test of methods for rapid assesment of biodiversity. Ecological Applications 6(2): 594-607. Pojar, J. 1993. Terrestrial Diveristy o f British Columbia. In Our living Legacy: Proceedinga of a Symposium on Biological Diversity. M . A . Fenger, E . H . Mi l le r , J.F. Johnson, and E.J.R. Will iams (eds.). Royal British Columbia Museum: Victoria, B . C . Pp. 177-190. Refseth, D . 1980. Ecological Analyses of Carabid Communities-Potential Use in Biological Classification for Nature Conservation. Biological Conservation 17: 131-141. Samways, M . J . 1989. Insect Conservation and the Disturbance Landscape. Agriculture, Ecosystems, and Environment 27: 183-194. Samways, M . J . 1993. Insects in biodiversity conservation: some perspectives and directives. Biodiversity and Conservation 2: 258-282. Southwood, T . R . E . 1978. Ecological Methods: with particular reference to the study of insect populations. Chapman and Hal l : New York. Spence, J.R. and D . H . Spence. 1988. O f Ground-Beetles and Men: Introduced Species and the Svnanthropic Fauna of Western Canada. Memoirs of the Entomological Society of Canada 144: 152-168. Spence, J.R., D . W . Langor, J. Niemela, H . A . Carcamo, and C R . Currie. 1996. Northern forestry and carabids: the case for concern about lod-growth species. Annales Zoologici Fennici 33: 173-184. St i l l , G . , A . MacKinnon, and R. Planden. 1994. Forest, Range, and Recreation Resource Analysis. Crown Publications: Victoria, B C . Terrell-Nield, C . 1990. Is it possible to age woodlands on the basis o f their carabid beetle diversity? The Entomologist 109(3): 136-145. Thiele, H . U . 1977. Carabid Beetles in Their Environments. Springer-Verlag: Berl in. Turin H . and P.J . den Boer. 1988. Changes in the Distribution of Carabid Beetles in the Netherlands Since 1880. II. Isolation of Habitats and Long-term Time Trends in the Occurrence of Carabid Species with Different Powers of Dispersal (Coleoptera: Carabidae). Biological Conservation 44: 179-200. 71 Wall in , D.O. , F.J . Swanson, and B . Marks. 1994. Landscape Pattern Response to Changes in Pattern Generation Rules: Land-Use Legacies in Forestry. Ecological Applications 4(3): 569-580. Weaver, J.C. Indicator Species and Scale of Observation. Conservation Biology 9(4): 939-942. Weseloh, R . M . 1997. Orientation of Calasoma syncophanta L.(Coleoptera: Carabidae)in forests : insights from visual responses to objects. The Canadian Entomologist 129: 347-354. Zar, J .H. 1984. Biostatistical Analysis. Prentice-Hall Inc.: Englewood Cliffs, N . J . 72 A p p e n d i x 1 Trap Collection Dates Mara Mountain (MM) Series number Traps set Traps collected Year n o o n A u g 10 A u g 2 6 1992 100(1 A u g 2 6 Sept 0 9 1 9 9 2 2 0 0 0 Feb 17 Mar 03 1993 3 0 0 0 W Mar 03 Mar 2 6 1993 3 0 0 0 A u g 11 A u g 25 1993 4 0 0 0 A u g 2 5 Sept 08 1993 5 0 0 0 Dec 0 7 Jan 31 1 9 9 3 / 1 9 9 4 6000 M n t T Icprl 7<H MI A u g 0 4 A u g 18 1 9 9 4 8 0 0 0 A u g 18 Sept 01 1 9 9 4 9 0 0 0 A u g 03 A u g 17 1995 10 ,000 A u g 17 A u g 31 1995 11 .000 Jan 15 Mar 15 1 9 9 6 12 .000 July 1 July 15 1 9 9 6 1 3 , 0 0 0 July 15 July 2 9 1 9 9 6 14 .000 A u g 13 A u g 2 7 1 9 9 6 1 5 . 0 0 0 A u g 2 7 Sept 10 1 9 9 6 1 6 . 0 0 0 Jan 10 Mar 2 6 1 9 9 7 1 7 , 0 0 0 Jul 1 Jul 14 1 9 9 7 18 .000 Jul 14 Jul 2 8 1 9 9 7 19 .000 A u g 11 A u g 25 1 9 9 7 2 0 , 0 0 0 A u g 2 5 Sept 8 1 9 9 7 73 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
https://iiif.library.ubc.ca/presentation/dsp.831.1-0089098/manifest

Comment

Related Items