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Title: Spatial associations between infestations of mountain pine beetle and landscape features in the Peace River Region of British Columbia.
Contributors: Honey-Marie C. de la Giroday (author), Brian Aukema (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: An immense outbreak of the mountain pine beetle, Dendroctonus ponderosae Hopkins, currently covers a cumulative area of 14.5 million hectares of mature pine forests across the provinces of British Columbia and Alberta, Canada. In 2004, the first outbreaking populations of mountain pine beetle were observed in northeastern British Columbia, an area not considered part of the insect's native range. My thesis examines how landscape features and their orientation influence establishment patterns of the insect. Mountain pine beetle spread between 2004 and 2006 in patterns similar to a propagating wave, likely due to long-distance dispersal into the region. Large glacially-eroded valleys, canyons, deeply incised streams, local and midslope ridges or small hills in valleys and plains, and open slopes were often positively associated with infestations, providing evidence that the interaction of meso-scale convective currents and topography can mediate patterns of establishment. The orientation of landscape features also influenced establishment, as southwest-facing areas and linear features aligned in northeast-southwest directions were associated with increased densities of infestations in 2006. Management activities were typically associated with a decline in the density of mountain pine beetle infestations in the following year, indicating that such activities were effective in preventing short-distance dispersal of the insect. I found no evidence that anthropogenic activities such as transport and storage of infested material increased establishment of mountain pine beetle across the research area. These results may be used to prioritize preemptive treatments in mountainous regions in the absence of long-distance inputs of mountain pine beetle into expanding ranges. --P.ii.
Discipline: Biology
Date added: 2017-03-30T17:06:41.78Z

Title: The effect of substrate rearing on the growth, development, and survival of larval white sturgeon (Acipenser transmontanus) during early ontogeny.
Contributors: Marcus A. Boucher (author), Mark Shirmpton (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: White sturgeon, Acipenser transmontanus, were reared in the presence (gravel) or absence (bare) of substrate at either 13.5 or 17.5°C during the yolk sac phase. Fish reared in gravel were transferred to bare tanks at emergence from substrate and reared to 46 days post hatch (dph). At any given dph or Accumulated Thermal Unit (ATU), the fish reared in gravel were significantly larger and survival was higher than those reared without substrate at both temperatures (T). Cumulative survival was lower at high T and was 20% greater in gravel-reared larvae in both T. Yolk absorption rate did not vary between bare and gravel, but was significantly greater at high T. Yolk absorption efficiency was greatest in gravel-reared fish, but did not vary with T. Liver histology indicated that fish reared in gravel had significantly greater quantity of lipid during the yolk sac phase. In a second experiment, yolk sac larvae were reared in the presence (gravel or bio-spheres) or absence (bare) of substrate at 13.5°C and respirometry used to measure both routine and maximum metabolic rate for assessing metabolic scope. Larvae reared in gravel had significantly greater metabolic scope, and whole body glycogen was significantly greater in larvae reared in both substrates at 8 dph indicating that substrate rearing may provide a greater capacity of growth and development at a time of intense organogenesis. Histological analysis of the liver showed greater lipid and glycogen in larvae reared in substrate. These findings suggest that larvae reared without substrate may divert more of their energy to non-growth related processes, such as swimming activity, which was observed but not quantified. Thus, larvae reared without substrate may be at a significant physiological disadvantage, leaving less energy for growth and development. --P. i.
Discipline: Biology
Date added: 2017-03-30T17:10:09.327Z

Title: Use, selection and winter foraging patterns among woodland caribou herds in central British Columbia.
Contributors: Elena S. Jones (author), Michael Gillingham (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: No abstract available.
Discipline: Biology
Date added: 2017-03-30T17:03:06.163Z

Title: Trade-offs in the early development of tree swallows (Tachycineta bicolor): offspring characteristics, offspring quality, and parental care
Contributors: Sophia A. Unger (author), Russell Dawson (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: Life-history theory predicts that because organisms have limited resources available to them, they must make decisions to prudently allocate resources in a way that maximizes fitness. Therefore, there is expected to be a trade-off between current reproductive effort and future survival and reproduction, with those individuals investing in a current breeding attempt doing so at a cost to their own survival and/or future fecundity. Altricial birds rearing young are consequently expected to be prudent in their allocation of resources between brood-maintenance and self-maintenance, and their allocation choices may be influenced by numerous offspring characteristics that potentially indicate offspring "quality" or condition. My thesis had three main goals: 1) to understand if the smallest nestling tree swallows in a nest are of inherent poor "quality", or if they are the smallest simply due to being outcompeted by their older and larger siblings 2) to investigate whether, in an environment with parasites, it is the parents or their offspring who bear the costs associated with parasitism and 3) to better understand the function of gape and flange colouration in nestling tree swallows. Overall, I wanted to understand how each of these nestling characteristics affect, and are affected by, parental life-history trade-offs. By pairing observational data with a cross-fostering experiment, I determined that both total egg mass and yolk mass increased with order of laying. Nestlings that hatched earlier in the hatching sequence and were manipulated to be smaller within the size hierarchies in nests performed in a similar fashion as if they had retained their size advantage, but had lower immune responses, which may be because these earlier-hatched nestlings hatched from earlier-laid eggs with smaller yolks. By manipulating parasite levels in nests and then comparing nestling immune function and growth, and parental provisioning rates with control nests in a three-year study, I observed no significa
Discipline: Biology
Date added: 2017-03-29T17:30:37.599Z

Title: Towards an understanding of the management of pine-lichen woodlands in the Omineca region of British Columbia.
Contributors: Randall Gregory Sulyma (author), Darwyn Coxson (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: No abstract available.
Discipline: Biology
Date added: 2017-03-30T16:57:38.735Z

Title: Temperature preference and distribution of juvenile Arctic grayling (Thymallus arcticus) in the Williston watershed, British Columbia Canada.
Contributors: Sarah C. F. Hawkshaw (author), Mark Shrimpton (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: The habitat requirements of juvenile Arctic grayling (Thymallus arcticus) were assessed in the Williston watershed, British Columbia, where the population is currently red-listed (critically imperiled). Temperature preferences of juvenile Arctic grayling was assessed behaviorally using a shuttlebox system, and an information theoretic approach analysis of logistic regression models was used to evaluate the influence of environmental factors on the distribution of juvenile Arctic grayling throughout the Williston watershed. Temperature preference of juvenile Arctic grayling did not vary between the two tributaries in the watershed (p = 0.77) and the average preferred temperature was 16.84 ± 0.66 °C (n = 28). Comparisons of the preferred temperature to ambient water temperatures suggested that juvenile Arctic grayling will avoid areas where maximum water temperature is above the preferred temperature. There was a positive association between juvenile Arctic grayling occurrence and stream order (SO) and stream order multiplied by distance from the Williston reservoir (SDRxSO), as well as a negative association with the mean daily water temperature variance (varT) and average water temperature (aveT). Overall these findings suggest that large river systems are important juvenile Arctic grayling habitat and management decision should be made to ensure protection of this habitat throughout the range of this species. --P. ii.
Discipline: Biology
Date added: 2017-03-30T17:09:21.087Z

Title: Interrelationships between weather, parasitic insects, and barren-ground caribou (Rangifer tarandus groenlandicus) behaviour in Northwest Territories and Nunavut.
Contributors: Leslie A. Witter (author), Christopher Johnson (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: The Bathurst barren-ground caribou (Rangifer tarandus groenlandicus) herd decreased by 90% from 1986-2009. Increased intensity of insect harassment due to climatic warming is hypothesized as a factor contributing to the decline. I monitored weather, trapped insects, and recorded caribou behavior during 2007-2009. Oestrid fly (Oestridae) presence, and mosquito (Culicidae) and black fly (Simuliidae) activity/abundance were best explained by temperature, wind speed, light intensity, barometric pressure, relative humidity, vegetation, topography, and location. Time of day and growing degree days also affected mosquito and black fly levels. Conditions favouring mosquito activity declined, while those favouring black and oestrid fly activity increased since the mid 1980s. Mosquitoes had relatively little effect on caribou behavior. Insect avoidance increased when oestrids were present or black flies were active at moderate-high levels. Understanding differential effects of macroparasites on Rangifer behavior is necessary to predict herd dynamics in the context of a changing climate across northern Canada. --P.ii.
Discipline: Biology
Date added: 2017-03-30T17:08:33.261Z

Title: Using bioclimatic envelope modelling to incorporate spatial and temporal dynamics of climate change into conservation planning.
Contributors: Nancy-Anne Rose (author), Philip Burton (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: Current and predicted trends in climate are diverging from historic norms, thereby compromising the equilibrial basis of our resource management frameworks. This study investigates the impacts of climate change on biodiversity in the context of conservation planning for British Columbia's Central Interior. I used bioclimatic envelope modeling and a climate interpolation and general circulation model downscaling tool to assess 73 rare plant species, 103 biogeoclimatic variants, and 30 terrestrial ecosystem units. I mapped areas projected to support climate suitable for the persistence of those conservation targets through to the 2080s. Results illustrate the potential for disruptive change only 12% (24) of the 206 targets are projected to experience persistent climate at their current locations. Although strong overlap among locations projected to persist for different targets was not found, and those areas meeting multiple objectives (including value independent of climate change) are clear priorities for protection. This methodology can function as a valuable tool for conservation planners and resource managers. --P. [i]
Discipline: Biology
Date added: 2017-03-30T17:07:38.621Z

Title: Lichen and bryophyte diversity, nitrogen and carbon dioxide exchange from sub-boreal spruce forest floors in central British Columbia.
Contributors: Rachel S. Botting (author), Arthur Fredeen (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: No abstract available.
Discipline: Biology
Date added: 2017-03-30T17:02:15.818Z

Title: The relationship between climate and outbreak dynamics of Dothistroma needle blight in northwest British Columbia, Canada.
Contributors: Cedar Welsh (author), Kathy Lewis (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: No abstract available.
Discipline: Biology
Date added: 2017-03-30T17:03:38.844Z

Title: Effect of Formica aserva Forel (Hymenoptera: Formicidae) on ground dwelling arthropods in central British Columbia.
Contributors: Kendra Gail Schotzko (author), Staffan Lindgren (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: Carabids and spiders have potential as bioindicators, but may experience niche overlap with some ants. While some studies have uncovered mixed responses by these taxa to ants, negative associations are frequently found. We examined carabids and spiders in a British Columbia clearcut in zones colonized and non-colonized by Formica aserva ants. The number of carabids captured in colonized and non-colonized zones differed significantly from expected, and species-specific patterns were observed. While the activity-abundance of most spider species did not differ between zones, the activity-abundances of five species were significantly different in colonized and non-colonized zones. We also investigated behavioural responses by the carabid Pterostichus adstrictus to signals of ant presence, and observed that this carabid avoided crushed F. aserva gasters. Our results indicate that F. aserva may influence the activity-abundance of some carabid and spider species, and that some carabids may be able to detect F. aserva chemical signals. -P. ii.
Discipline: Biology
Date added: 2017-03-30T17:13:04.579Z

Title: Temporal and spatial differences in smolting among sockeye salmon (Oncorhynchus nerka) populations throughout fresh- and seawater migration and the effect of water temperature on the smolt window
Contributors: Marley Carter Bassett (author), Mark Shrimpton (thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: Salmon smolts undergo physiological changes in the spring that are important for successful migration to seawater. Species that are widely distributed may differ in timing of physiological changes associated with smelting. In my first study, I compared indices of smolt characteristics among populations that differ in migration distance to the ocean. Fraser River sockeye salmon from four regions in the watershed were intercepted at different times during migration to characterize the parr-smolt transformation. Gill Na⁺/K⁺-ATPase (NKA) activity was highly variable at the start of migration, and was not explained by the distance from the ocean. Gill NKA activity changes with migration were also highly variable, but consistently smolts in the ocean had the highest gill NKA activities. The nature of smelting appears to be dynamic and variation was not based on the region of origin, timing during migration, or on the year of migration. The duration of time when anadromous salmon are able to survive in seawater – the smolt window – is influenced by temperature. In my second study, I found that warm water temperature abbreviated the smolt window. Additionally, isoforms of the gill NKA enzyme and endocrine signals suggest that the stimulus for smelting occurred prior emigration from the natal lake. Modeling the thermal experience that smolts encountered as they migrated downstream to the ocean in 2012 suggested Chilko fish did not experience temperatures as warm as the temperatures that abbreviated the smolt window in my study. Furthermore, climate change projections for temperature may not limit successful emigration of Chilko sockeye salmon smolts from central British Columbia to the ocean – but changes in other abiotic and biotic factors may confound this prediction.
Discipline: Biology
Date added: 2017-03-29T17:27:32.805Z

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
Date added: 2017-04-10T22:13:27.595Z

Title: Associations of secondary bark beetles with dying and live lodgepole pine in the post-outbreak phase of mountain pine beetle, Dendroctonus ponderosae (Hopkins), in the central interior of British Columbia, Canada.
Contributors: Ewing Teen (author), Brian H. Aukema (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: Dendroctonus ponderosae (Hopkins) or mountain pine beetle is a native bark beetle (Coleoptera: Curculionidae: Scolytinae) that feeds on more than 20 species of pine in western North America. In British Columbia, its principal host is lodgepole pine (Pinus contorta var. latifolia Engelmann). As a primary bark beetle, D. ponderosae kills its host at epidemic stages, exerting profound landscape-level mortality. As of 2012, D. ponderosae has caused the loss of 726 million cubic meters of timber, covering an area of 17.5 million hectares of mature pine forest in British Columbia and Alberta. Small diameter hosts are not suitable for D. ponderosae, however, creating a niche for the secondary bark beetles, including Ips pini (Say), Pseudips mexicanus (Hopkins), and Orthotomicus latidens (LeConte). At the post-epidemic stage of D. ponderosae, we found the rate of new mortality was approximately 4%, which 1% of the mortality was associated with a complex of secondary bark beetles, and not D. ponderosae, as the principal mortality agent in those stands. This finding suggests that at high population densities, secondary bark beetles are potential mortality agents of residual pines, sustaining the apparent outbreak of D. ponderosae by killing smaller diameter trees, with the highest rate of mortality among younger stands. --P. ii.
Discipline: Biology
Date added: 2017-03-30T17:10:02.505Z

Title: Host colonization patterns, cues mediating host selection and calibration of field surveys with estimates of population abundance of leptoglossus occidentalis in a seed orchard.
Contributors: Tamara A. Richardson (author), B. Staffan Lindgren (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: The western conifer seed bug, Leptoglossus occidentalis Heidemann (Hemiptera: Heteroptera: Coreidae) is an important pest in southern interior British Columbia seed orchards. In spite of its pest status, host colonization patterns and cues mediating host selection have not been well studied. Additionally standardized population census methods, which are essential for the development of economic damage thresholds, have not yet been established. I examined spring immigration patterns of L. occidentalis into a lodgepole pine seed orchard in 2008 and 2009. In 2008, significant spatial gradients of L. occidentalis-infested trees were found in four of seven surveys, however, they were not directionally consistent. In 2009 a significant spatial gradient was found in a single survey. Spatial gradients may have been detected more easily in 2008 than 2009, as counts of L. occidentalis were much larger. I also assessed whether L. occidentalis exhibits clonal preference, if preferences remained consistent between 2008 and 2009, and examined whether cues responsible for such preferences could be identified. I found that clone preference remained consistent between 2008 and 2009 and that predefined clone preference classes had significantly different levels of the monoterpenes [α]-pinene, [δ]-3 carene, and p-cymene. Additionally, L. occidentalis was found more frequently on clones with cones of greater diameter and weight. Finally, in 2009 I conducted mark-release-recapture studies with corresponding walk-through surveys for L. occidentalis both in lodgepole pine and Douglas-fir seed orchards. I was unable to establish mathematical relationships between population estimates and walk-through surveys in either location. Data from these surveys indicated that the walk-through survey were unreliable, at least at low populations. Studies exploiting cues attractive to L. occidentalis for trap design and additional studies to establish standardized survey methods are recommended as L. occidentalis continues to cause dam
Discipline: Biology
Date added: 2017-04-11T21:12:11.935Z

Title: Impacts of industrial developments on the distribution and movement ecology of wolves (Canis lupus) and woodland caribou (Rangifer tarandus caribou) in the South Peace region of British Columbia.
Contributors: Elizabeth Parr Williamson-Ehlers (author), Christopher Johnson (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: Habitat alterations from anthropogenic disturbances across northeastern British Columbia have resulted in large-scale modifications to predator-prey dynamics. I used GPS collar locations and field data to quantify the responses of wolves (Canis lupus) and woodland caribou (Rangifer tarandus caribou) to the cumulative effects of industrial disturbance. I developed seasonal resource selection functions for caribou and count models of habitat occupancy for wolves. I also related wolf movements to caribou habitat and industrial features. Caribou occupying the boreal forest likely are more at risk from industrial developments. My results suggest that caribou occupying these ecosystems are subject to disturbance by human activity and a greater risk of spatial interactions with wolves. However, these relationships are complicated by the positive and negative responses of wolves to landscape change and the distribution of other prey and predator species. --P. i.
Discipline: Biology
Date added: 2017-03-30T17:13:00.467Z

Title: Decomposition and carbon loss in lodgepole pine (Pinus contorta var. latifolia) wood following attack by mountain pine beetle (Dendroctonus ponderosae)
Contributors: Benita Kaytor (author), Art Fredeen (Thesis advisor), Philip Burton (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: Mountain pine beetle (MPB)-killed wood remaining on the landscape is predicted to release significant amounts of carbon to the atmosphere as it decays. A lack of field-based wood decomposition data for validating simulation models reduces certainty in such predictions. Using a chronosequence approach, I quantified decomposition of MPB-killed wood to improve decay rate parameters. Changes in carbon density over time and climatic variability showed distinct patterns for bole position categories. Snag carbon density was similar to that of live lodgepole pine, and did not change considerably with time or climatic influences. Decay in suspended boles increased with summer precipitation, but declined with increasing summer temperature, suggesting decay in elevated boles is moisture-limited on warmer sites. Down boles decayed four times faster with increasing proximity to the soil than suspended boles, but did not clearly reflect climatic influences. Position of dead boles appears more important for wood decay than previously thought. --Leaf ii.
Discipline: Biology
Date added: 2017-03-29T17:29:49.72Z

Title: A microsatellite analysis of the western Canadian mountain pine beetle (Dendroctonus ponderosae) epidemic: phylogeography and long distance dispersal patterns
Contributors: Nicholas V. Bartell (author), Brent Murray (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: The mountain pine beetle (MPB) is an eruptive insect that is currently causing an outbreak of record size in Western Canada. A lack of long distance MPB dispersal data has limited our understanding of and ability to manage MPB epidemics. My goal was to determine the MPBs Western Canadian population structure, upon which dispersal patterns may be superimposed. I analyzed MPBs from 35 infested lodgepole pine stands at six microsatellite loci. The MPB exhibited strong and significant Western Canadian population structure. This population structure was incongruent with the structure of its primary symbiont, O. clavigerum, but congruent with the structure of its primary host, P. contorta. Novel fungal selection pressures have probably caused the discrepancy in beetle/fungus phylogeography. A result of Western Canadian MPB population structure alternately contrasts and supports population structure previously reported for Scolytids, including MPBs. The partitioning of MPB population structure into a Northern and Southern group is most likely the result of postglacial recolonization and differences in MPB population dynamics. Primarily using my genetic data, I inferred the historical movement patterns of the MPB in Western Canada. I found no evidence that the epidemic spread from an epicenter in Tweedsmuir Provincial Park. My data support multiple sources for the current epidemic I suggest that regional population expansions have caused the rapid escalation in the severity of the current epidemic. MPB movement patterns and atmospheric wind data were concordant winds in Western Canada are predominantly westerly or southwesterly, which was the predominant direction of inferred movements among MPB populations. In contrast, current MPB population structure best fits a 30-year climatic suitability distribution for a historical (1921-1950) as opposed to the most current (1971-2000) period. The population genetics of long distance MPB dispersal, an evolutionary theory for MPB population dynamics, and MPB '~range expans
Discipline: Biology
Date added: 2017-04-10T22:08:40.075Z

Title: Spore dispersal and infection of lodgepole pine by Dothistroma septosporum in northwest British Columbia.
Contributors: Kennedy Boateng (author), Kathy Lewis (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: Spore dispersal and infection by Dothistroma septosporum which has severely attacked lodgepole pine plantations in northwest British Columbia were studied. Spore abundance was assessed at different distances and heights from single juvenile tree inoculum sources and microclimatic factors were recorded during two consecutive years. One- year-old lodgepole pine seedlings were exposed to natural conditions at the study sites for inoculation. Conidia were assessed from spore traps from June to September in 2009 and were present in the samples whenever rain fell, with a peak in July. It was rare to detect spores more than 2 m away from inoculum sources. The timing and number of conidia dispersed were strongly tied to the climatic variables, particularly rainfall. Infection of the seedlings by the fungus was strongly influenced by the exposure periods, number of spores and high relative humidity. The results suggest increasing the planting distances between susceptible tree species through mixed species plantations and promoting dry conditions within pine plantations may be valuable strategies to reduce the spread of the disease and manage lodgepole pine plantations in the area. --P. ii.
Discipline: Biology
Date added: 2017-03-30T17:09:16.454Z

Title: Species and assemblage responses of carabidae (coleoptera) to forest harvesting: contrasting clearcut and patch retention removals in high-elevation forests of central British Columbia
Contributors: Jeffery P. Lemieux (author), B. Steffan Lindgren (Thesis advisor), University of Northern British Columbia (Degree granting institution)
Abstract: No abstract available.
Discipline: Biology
Date added: 2017-04-11T21:16:58.883Z