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Title: Fungal community assessment in Canadian arctic soils from Alexandra Fiord, Ellesmere Island, Nunavut.
Contributors: Young Joo Jenny Lee (author), Keith Egger (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: Fungal communities in arctic soils tend to be less diverse compared to the communities in temperate forest soils due to the harsher environmental conditions. Even in a single arctic site such as Alexandra Fiord, considered a terrestrial arctic oasis, fungal diversity is expected to be lower compared to soils in less extreme environments. We hypothesized that variations in environmental factors would play an important role in determining fungal community structure, as the Alexandra Fiord soils exhibits considerable environmental variation in a small geographic area. To test this hypothesis, we collected soil samples from three sites across the landscape and performed length-heterogeneity polymerase chain reaction (LH-PCR) analyses using ITS3 and NLB4 primers, which have been used successfully to characterize complex communities. Our results showed that there were large relative differences in fungal community structure between the sites. At the Alexandra Fiord Highland Dolomitic site diversity was low with genotypes relatively evenly distributed, whereas Alexandra Fiord Highland Granitic and Alexandra Fiord Lowland sites had higher diversity and a less even distribution of genotypes with a few occurring at a high frequency and many rare species. Among environmental variables, soil moisture, temperature, DOC, DON, C:N ratio and soil pH were significant influential factors in determining fungal community structure. Among these environmental factors, pH showed the strongest correlation with the fungal community data. --P. ii.
Discipline: Biology

Title: Ectomycorrhizal fungal communities of Douglas-fir on diverse soil lithologies of central British Columbia.
Contributors: Kirsten M. Thompson (author), Huques B. Massicotte (Thesis advisor), Paul T. Sanborn (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: Ectomycorrhizal (ECM) fungi are symbiotic partners of most conifers and improve host health by increasing access to nutrients and water in return for photosynthates. ECM fungi have been demonstrated to ameliorate the effects of some harsh soil chemical conditions on plants. Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) is found on and off extreme bedrock-derived soils in central British Columbia The objectives of this study were to describe the soils and Douglas-fir forests found on the diverse lithologies of the Fort St. James area and to assess seedling health and ECM fungal communities of Douglas-fir grown on these soils by morphological and molecular means. Fifteen ECM morphotypes, 12 basidiomycetes and 3 ascomycetes were identified with Tuber anniae (Ascomycota) unique to ultramafic soils. Three morphotypes (E-strain, Cenococcum geophilum, and Rhizopogon cf. villosulus) were ubiquitous on all sites and no connection between parent material and ECM communities was established. --Leaf ii.
Discipline: Biology

Title: Social and extra-pair mate choice by female tree swallows: The importance of male and nest-site quality, and consequences for offspring performance.
Contributors: Erin L. O'Brien (author), Russell Dawson (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: No abstract available.
Discipline: Biology

Title: Local adaptation to cold temperatures by larval coho salmon (Oncorhynchus kisutch) from different populations throughout British Columbia
Contributors: Kimberley Tuor (author), Mark Shrimpton (thesis advisor), University of Northern British Columbia College of Science and Management (Degree granting institution)
Abstract: The influence of environmental variables on larval development of coho salmon (Oncorhynchus kisutch), with specific focus on the influence of near-freezing incubation temperatures, was examined across populations within British Columbia. A survey across the geographical distribution within British Columbia was conducted to determine the range and variability of incubation temperatures experience by incubating coho salmon. Temperatures throughout incubation differed significantly among locations, averaging approximately 1 °C in colder interior locations and approximately 5 °C in warmer coastal locations. Environmental variables influenced egg size, fecundity, female size and gonadal somatic index, such that higher latitude of spawning grounds increased, larger systems decreased, and increased temperatures experienced by a population increased the four life-history traits. Suggesting significant effects of latitude of spawning grounds, size of spawning system and temperatures experienced by a population on shaping patterns of reproductive investment. ...
Discipline: NRES-Biology

Title: Reproductive success and habitat selection of sharp-tailed grouse (Tympanuchus phasianellus) in the Peace River region, northeast British Columbia.
Contributors: Alicia D. Goddard (author), Russell Dawson (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: No abstract available.
Discipline: Biology

Title: The habitat ecology of the post-metamorphic coastal tailed frog (Ascaphus truei).
Contributors: Alexandria L. McEwan (author), Chris Johnson (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: The coastal tailed frog (Ascaphus truei) has a biphasic life-history that includes the use of high-elevation streams and adjacent old growth forests. This species is at risk from a variety of land-use activities that result in younger and more fragmented terrestrial habitats. I investigated the fine-scale spatial ecology of post-metamorphic tailed frog populations as revealed by seasonal variation in activity and movement. I used an Information Theoretic Model Comparison approach to relate tailed frog captures in pitfall traps to sets of explanatory factors and infer habitat use by adult tailed frogs located with VHF radio transmitters. Trap data suggested that variation in the relative abundance and distribution was attributed to time of year, associated with reproductive activity seasonal trends in local climate canopy closure and distance to the larval stream. The most parsimonious logistic regression model for both years of trapping data demonstrated good' predictability (Area Under the Curve (AUC) > 0.7). Data from 24 tailed frogs with radio transmitters (8 males, 16 females) fitted to a resource selection function suggested that tailed frogs were positively associated with habitats containing decayed coarse woody debris (CWD), less light, adjacency to the larval stream, wet site types, and cool temperatures (11-12C). When compared to males, females were more selective in their choice of habitat (AUC > 0.7). Overall, the relationship between distribution and activity of tailed frogs was reflective of reproductive phenology in combination with micro-site or broader climatic conditions. Thus, habitat protections should reflect the behavior and habitat of the species as it varies across spatiotemporal scales.
Discipline: Biology

Title: Detection of shifts in microbial functional gene (nosZ and nifH) distribution due to long term warming of a high Arctic soil.
Contributors: Jennifer K. M. Walker (author), Keith Egger (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: No abstract available.
Discipline: Biology

Title: Effects of supplementary nitrogen on biomass and nitrogen accumulation in the sundew Drosera capensis L.
Contributors: Brian M. Bruzzese (author), University of Northern British Columbia (Degree granting institution)
Abstract: The effect of nutrient supplementation on biomass and nitrogen accumulation in the insectivorous plant Drosera capensis L. was studied under laboratory conditions using supplementary feeding of ammonium chloride (Nr4CI) to plant leaf surfaces. The nitrogen solution used was based on a standard concentration of 157.6 mM NH4CI. Drosera capensis did not differ significantly in biomass or nitrogen accumulation from concentrations of 50%, 75%, 100%, 150%, or 200% of nutrient fertilizer when applied to the foliage. Reproductive structures were observed in higher numbers in those plants treated with higher concentrations of Nr4Cl but no relationship was found between reproductive structures and biomass or nitrogen concentrations. The results of this experiment potentially indicate that D. capensis can grow and initiate reproductive structures without additional nutrients above which already exist in the soil mixture. The results also suggest that D. capensis does not readily absorb NH4CI through its leaves.
Discipline: Biology

Title: Vertical distribution, nitrogen content, and natural 15n and 13c abundance of epiphytic macrolichen functional groups and soil in sub-boreal spruce forests of central British Columbia.
Contributors: Anna Kobylinski (author), Art Fredeen (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: Forest canopy research in old growth sub-boreal spruce (SBS) forests of British Columbia's (BC) central interior plateau forests has revealed rich epiphytic lichen communities that represent a critical interface between the atmosphere and the soil. Cyanolichens can contribute nitrogen (N) to forests by fixing atmospheric N₂ gas into available, reduced forms such as ammonium (NH₄⁺). Variations in the ratios of the natural abundance of the stable isotopes of N (i.e. ¹⁴N:¹⁵N) in forest ecosystem components represent an important in situ method to estimate N inputs from biological N₂-fixation. I used this method to evaluate the importance of epiphytic cyanolichens to N inputs in sub-boreal forest ecosystems of central interior BC. Four old growth sub-boreal forest sites were chosen based on cyanolichen abundance and diversity – two High Cyano sites and two Low Cyano sites. Interior hybrid spruce (Picea glauca x engelmannii) and subalpine fir (Abies lasiocarpa) trees were randomly selected at the High and Low Cyano sites and access into canopies achieved through a single-rope technique. Vertical distributions of lichen biomasses were quantified and a vertical niche of foliose chlorolichens was observed in the canopy where cyanolichens were deficient. Lichen functional groups, conifer needle, and soil samples were obtained and their ¹⁵N:¹⁴N, %N, ¹³C:¹²C, %C contents measured using a continuous flow gas isotope ratio mass spectrometer. Comparisons of stable isotope ratios between High and Low Cyano sites were made. Sub-boreal forest epiphytes and foliage had isotopically lighter N (i.e. more ¹⁴N) at sites with high cyanolichen abundance, indicative of greater inputs of biologically fixed-N.
Discipline: Biology

Title: Carbon budget of forest products harvested from mountain pine beetle-attacked forests in the Prince George region
Contributors: Wyatt Stanley Klopp (author), Art Fredeen (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: The risk of the mountain pine beetle (MPB Dendroctonus ponderosae Hopkins) attacked forests contributing to global climate change has many stakeholders looking for potential mitigation solutions in British Columbia, Canada. To date, these efforts maintain the notion of proactive forest management, yet lack a clear understanding of the contribution of forest products to mitigating greenhouse gas (GHG) emissions. My study addressed this ambiguity by estimating the GHG emissions attributable to current and proposed forest products harvested from MPB-attacked forests. My findings found relative differences between two distinct forest products (lumber, pellets), but ultimately their outcomes are contextually driven. Moreover, the cut-off criteria and assumptions governing biogenic GHG emissions (i.e. carbon neutrality) were found to have a large impact on the industrial forest C budget. The lasting contribution of this thesis is in its reconciliation of the current dichotomy in the fields of environmental science and policy with respect to the contribution of forest products to forestry's efforts in mitigating climate change. --Leaf ii.
Discipline: Biology

Title: Response of Scouler's willow (Salix scouleriana) to mechanical brushing: Implications to the quality of winter browse for moose (Alces alces).
Contributors: Roy Van Rea (author), Michael P. Gillingham (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: No abstract available.
Discipline: Biology

Title: Will climate change alter Arctic nitrogen budgets? Impacts of warming and fertilization on nitrogen fixing microbial communities at Alexandra Fiord, Ellesmere Island, Nunavut.
Contributors: Julie R. Deslippe (author), Keith Egger (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: The impacts of simulated climate change (warming and fertilization treatments) on diazotroph community structure and activity were investigated at Alexandra Fiord, Ellesmere Island, Canada. Open Top Chambers were randomly placed in a dwarf-shrub, cushion-plant dominated mesic tundra site in 1995. In 2000 and 2001 20N: 20P2O5: 20K2O fertilizer was applied at a rate of 5 g m-2year-1. Estimates of nitrogen fixation rates were made in the field by Acetylene Reduction Assays (ARA). Higher rates of N-fixation were observed 19-35 days post-fertilization but were otherwise unaffected by treatments and we hypothesize that microsite variation was a greater determinant of N-fixation rate than were the treatments applied. 'Nif'H genes were amplified from bulk soil DNA and analyzed by Terminal Restriction Fragment Length Polymorphism (T-RFLP) analysis. Nonmetric Multidimensional Scaling (NMS) was used to ordinate treatment plots in 'nif'H genotype space. 'Nif'H gene communities were more strongly structured by warming treatment late in the growing season, suggesting that an annual succession in diazotroph community composition occurs. [delta]15N analysis of plant and soil material from each treatment plot suggests that evergreen dwarf shrubs will depend more heavily on organic-N derived from mycorrhizae in warmer climates and that relative importance of symbiotic nitrogen fixation to the N-nutrition of 'D. integrifolia' will decline at this site.
Discipline: Biology

Title: Influence of prescribed fire on Stone's sheep and Rocky Mountain elk: Forage characteristics and resource separation.
Contributors: Krista L. Sittler (author), Katherine L. Parker (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: For over 30 years prescribed fire has been used as a management tool to enhance ungulate habitat in northeastern British Columbia (BC), where up to 7,800 ha are burned annually. Yet relatively few studies have quantified the role of fire on both plant and animal response, and whether it enables competition between focal grazing species such as Stone's sheep (Ovis dalli stonei) and elk (Cervus elaphus). Seven prescribed burns (150-1,000 ha) were implemented in the spring of 2010 and 2011 in the Besa-Prophet area of northern BC. I examined the response of Stone's sheep and elk to seasonal changes in forage quantity and quality by elevation in treatment versus control areas. I monitored vegetation and fecal pellet transects at a fine scale and used Landsat imagery, survey flights and GPS telemetry at a landscape scale. By one year after burning, forage digestibility and rates of forage growth were higher on burned than unburned areas. At both scales Stone's sheep and elk always used burns more than control areas in winter. Stone's sheep and elk appeared to partition their use of the landscape through topography and land cover. Increased use of burned areas suggests that prescribed fire enhanced habitat value for grazing ungulates in the short-term. By altering animal distributions, however, the use of prescribed fire has the potential to change complex predator-prey interactions in northern BC. --Leaf ii.
Discipline: Biology

Title: Spatial factors influencing northern mountain caribou (Rangifer tarandus) survival and distribution in the Telkwa Range
Contributors: Laura Vivian Grant (author), Christopher Johnson (Thesis advisor), University of Northern British Columbia College of Science and Management (Degree granting institution), Michael Gillingham (Committee member), Conrad Thiessen (Committee member)
Abstract: Human-induced habitat alteration has led to the decline of woodland caribou (Rangifer tarandus caribou) populations across Canada. The many challenges in conserving caribou are exemplified by a herd of northern mountain caribou in the Telkwa Range of central British Columbia. Despite population augmentation in the 1990s, this herd has declined to 18 individuals, yet mechanisms driving this decline are largely unknown. I used location data from caribou collared between 1991–2015 to investigate the influence of human disturbances – including forestry, roads, and recreation – on survival (N = 224) and habitat selection (N = 76). Results suggested that the decline of this herd was largely driven by a shift in predator prey dynamics following forest harvest. Further exacerbating the decline were the cumulative effects of disturbance in the Telkwa Range. Roads, recreation, and forestry influenced the distribution of the Telkwa caribou herd, ultimately affecting habitat availability and the ability of caribou to successfully manage predation risk.
Discipline: NRES-Biology

Title: Plumage characteristics in tree swallows Tachycineta bicolor: Honest signals of condition, reproductive investment and mating strategies.
Contributors: Pierre-Paul Bitton (author), Russell Dawson (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: Plumage characteristics are known to honestly reflect individual quality in many species of birds, and influence inter- and intra-sexual interactions between conspecifics. However, the information content of plumage signals, and the resulting influence on the receivers, can vary among species. In this study, I investigated the ecological significance of plumage characteristics of male and female tree swallows (Tachycineta bicolor). More specifically, I examined whether plumage characteristics are 1) honest indicators of individual quality, 2) associated with past or current reproductive investment and success, and 3) important to mating strategies in this species. ...Collectively, my results demonstrate that plumage characteristics in tree swallows convey information about individual quality and influence the behaviour of conspecifics.
Discipline: Biology

Title: Use and selection at two spatial scales by female moose (alces alces) across central British Columbia following a mountain pine beetle outbreak
Contributors: Matthew Scheideman (author), Michael Gillingham (thesis advisor), Katherine Parker (committee member), Douglas Heard (committee member), University of Northern British Columbia (Degree granting institution)
Abstract: Moose are a keystone species and play a substantive role in predator-prey systems, nutrient cycling, and forest succession. Following a mountain pine beetle (MPB) spread across British Columbia, I quantified seasonal home-range selection, home-range size and daily movements, and within home-range selection of GPS-collared female moose in three study areas. I used case-matched logistic regressions with individual seasonal home-ranges, and mixed-effects logistic regressions for seasonal locations of female moose to determine habitat selection at two spatial scales. Individual variation was evident at both home-range and within-home-range scales. Female moose selected lodgepole pine-leading stands at both spatial scales regardless of mass die-off due to MPB. Clear-cuts following the MPB outbreak were avoided in drier locations, and trade-offs between cover and browse were evident where disturbance due to salvage logging was highest. My findings indicate that MPB salvage-logging reduced moose habitat, and thereby, influenced selection by female moose.
Discipline: NRES-Biology

Title: Canopy macrolichen distribution in a very wet oldgrowth forest landscape of the upper Fraser River watershed.
Contributors: David N. Radies (author), Darwyn Coxson (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: Windward slopes of the inland mountain ranges in British Columbia support a unique temperate rainforest ecosystem. Continued fragmentation and loss of old-growth forests in this globally rare ecosystem, has led to calls for the identification of conservation priorities between remaining stands. This thesis addresses this concern by surveying the relative abundances of 37 canopy macrolichens over a 70-km² area of remaining old-growth (>140 years) forest in the upper Fraser River watershed, British Columbia, Canada. To ensure adequate representation of landscape-scale old-growth forest characteristics, we divided study plots equally among leading tree species and between broadly defined sites of wet' and dry' relative soil moisture. Other variables included: minimum mean annual temperature, mean annual precipitation, solar loading, and canopy openness. This thesis integrates two statistical techniques: Nonmetric Multidimensional Scaling ordination for analysis of lichen assemblages and logistic regression to evaluate the habitat conditions of a subset of 8 lichen species previously identified as old-growth associated'. Ordination suggested that community assemblages were greatly influence by both the presence and abundance of bipartite cyanolichens. These communities correlated well with increasing levels of relative soil moisture, temperature, precipitation, and canopy openness, with little to no significant effect of tree leading species. Logistic regression models identified relative soil moisture and temperature in all parsimonious models. Leading tree species, in combination with moisture and temperature, were important factors explaining the presence or absence of 5 of 8 modeled lichen species. The results of this thesis emphasize the importance of maintaining representative areas of old-growth forests that are potentially less prone to natural disturbances such as fire. Of concern to the maintenance of lichen populations in old-growth inland temperate rainforests
Discipline: Biology

Title: Microsatellite Variation in Mountain Pine Beetle ( Dendroctonus ponderosae Hopkins) in Western Canada: Spatial Genetic Analyses of Neutral Variation and Development of Genic Markers.
Contributors: G. D. N. Gayathri Samarasekera (author), Brent Murray (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: The mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins, is the most destructive pest of pine forests in western North America. In this study genetic variation of MPB in western Canada was explored both at neutral genomic and gene-linked microsatellite markers. To understand the spatial genetic structure and dispersal patterns, beetles from 49 sampling locations throughout western Canada were analyzed at 13 neutral microsatellite loci. The MPB exhibits significant north-south population structure in western Canada. The decline of genetic diversity from south to north and the lack of isolation by distance in the northernmost cluster are consistent with patterns expected from postglacial recolonization. In terms of dispersal patterns, northern outbreaks are consistent with an expansion out of Tweedsmuir Provincial Park, an early site of infestation in the current epidemic, while southern outbreaks are consistent with multiple centers of origin. To explore the gene-linked variation in the MPB genome, a panel of gene-linked markers was developed by screening an EST database of MPB. Fifty of 79 EST-derived markers developed were found to be polymorphic. A preliminary survey of five EST-derived microsatellite markers show evidence of selection at two loci. The genetic variation at another three loci was comparable with the genetic variation at neutral microsatellite markers. This study showed that the use of EST-derived microsatellites is a promising approach for identifying signatures of selection. Further, the new markers developed will be useful in constructing linkage maps and in performing genome scans and further landscape-scale genomic studies in both MPB and other related bark beetles. --P. ii.
Discipline: Biology

Title: Taxonomy, form, or function: Evaluating three approaches to using carabid beetles (Coleoptera: Carabidae) as bioindicators in a coastal forest.
Contributors: Sean G. Henderson (author), Staffan Lindgren (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: Arthropods have received considerable attention as biological indicators (bioindicators) as they are widespread, and easy to sample. Due to a shortage of trained taxonomists and limited resources, many taxa cannot be used, however. In this thesis, I use carabid beetles (Coleoptera: Carabidae), which are taxonomically well known, to compare three approaches of bioindication, using a traditional taxonomic approach as the baseline. The taxonomic approach distinguished coarse differences in forest canopy removal, as did a recognizable taxonomic unit approach. The latter failed to provide the same level of precision based on diversity data, however. A functional trait approach yielded non-significant results, but demonstrated potential to provide more in-depth information, albeit at a considerable additional investment of time. All three approaches were found to have advantages and disadvantages, so I conclude that the choice of approach will depend on the availability of resources and the objectives of each bioindication study. --P.ii.
Discipline: Biology

Title: Habitat selection and behavioural strategies of Stone's sheep in northern British Columbia.
Contributors: Andrew B. D. Walker (author), Katherine Parker (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: No abstract available.
Discipline: Biology