W. Garfield Weston Award for Northern Research (PhD), $ 50, 000

Transcription

1 W. Garfield Weston Award for Northern Research (PhD), $ 50, 000 Tammy Elliott PhD Candidate, Biology, McGill University Title: Determining processes underlying northern plant species distributions using evolutionary methods The biogeographic boundary separating the tundra and forest biomes is shifting northwards as the northern climate warms, and shifts in individual species distributions and entire communities are expected to accompany this change. Models predicting the geographic distributions of species often ignore the potential role of species interactions, which hinders our ability to forecast the impact of climate change on the future of biological diversity. My research near Schefferville, Quebec focuses on assessing the importance of inter-specific competitive interactions among plants in determining the species distributions across the region. I will examine whether closely-related species (e.g., congeners) tend to competitively exclude each other from local communities. As a next step, I propose to use a novel, DNA-based, quantitative method that permits defining the biogeographic boundary between the forest and tundra biomes on Mont Irony, Quebec. Detecting a transition zone between the biomes will require building a phylogenetic tree depicting evolutionary relationship among those species. Taken together, my PhD research will help with improving (1) our understanding of the multiple factors shaping biological diversity, (2) our prediction of species and community responses to climate change, and (3) our ability to track the impact of climate change on northern plant communities. Dominique Fauteux PhD Candidate, Biology, Université Laval Title: Direct and indirect effects of predation on lemmings in the high Arctic For nearly a century, lemmings have fascinated ecologists because of their regular population cycles which are characterised by high amplitude fluctuations. A thorough description of these fluctuations by Charles Elton in 1924 triggered the formulation of many hypotheses attempting to explain these mysterious cycles. It is still highly debated today whether lemming cycles are mainly driven by predation or by food availability. On Bylot Island, Nunavut, Canada, lemmings are characterised by 3-4 year cycles. Recent studies do not support the bottom-up (i.e. food) hypothesis because they have shown that this population only consumes a small fraction (< 10%) of the total annual primary productivity. In this study, we aim to test the hypothesis that predation drives the brown lemming (Lemmus trimucronatus) population cycles in the Canadian Arctic through a combination of direct (i.e. lethal) and indirect (i.e. non-lethal) effects. The direct effect of predation (i.e. mortality) might work synergistically with the indirect effects of predation, such as chronic physiological stress and reduced reproductive success, to produce the observed population cycles of lemmings. We Page 1 of 6

2 designed an experiment to exclude predators by building an eight-hectare fence covered with a net made of fishing line. To compare demographic parameters such as survival and recruitment lemmings will be marked-recaptured inside the fence as well as outside the fence. We will also compare the stress levels of lemmings inside and outside of the «predator exclosure» by measuring the corticosterone concentrations (i.e. stress hormone). Data will be collected during the summers of in order to cover a complete cycle. Brandon Laforest PhD Candidate, Environmental Studies, York University Title: An Integrative Approach to Polar Bear (Ursus maritimus) Management: Employing Fatty Acid Analysis, Movement Patterns, and Traditional Ecological Knowledge to Monitor the Effects of Climate Change on the Polar Bears of Southern Hudson Bay. My project examines the feeding ecology of polar bears in Southern Hudson Bay to link trends in polar bear foraging to underlying shifts in ecosystem composition, and to inform polar bear management practises in the region. Recent reductions to the sea ice extent of Hudson Bay and James Bay indicate an urgent need to better understand this subpopulation of bears, where significant decreases in body condition have already been observed. By fitting a select number of individual bears with satellite-linked GPS collars and analyzing fat samples of free-ranging bears to quantify diet composition, I will examine polar bear foraging and be able to link feeding ecology with habitat selection. Thus, quantifying the effects of habitat loss on the natural range and feeding habits of these bears at the individual- and population-level. This work will also provide insights into predicting the effects of climate change on more northern subpopulations of polar bears. This work will be coupled with aspects of Traditional Ecological Knowledge of Quebec James Bay Cree communities in the form of detailed GIS maps generated through community interviews with elders and hunters. This interdisciplinary approach will contribute to a more informed, holistic view of polar bear management in Southern Hudson Bay. Page 2 of 6

3 Linda Lait PhD Candidate, Biological Sciences, Memorial University of Newfoundland Title: A tale of four fishes: Examining the population genetic structure of Atlantic cod and three wolffish species using mitogenomics Population genetics is the study of how genetic variation is distributed in a species. It can be used to study the population structure of a species, identifying characteristics such as isolated or distinct populations and potential barriers to dispersal and gene flow. Despite years of study, the extent of population structure in many marine species remains enigmatic. My research looks at population structure in Atlantic Cod in the Northwest Atlantic, a species that underwent extensive population declines during the 1980s, using high-resolution molecular markers. By including arctic populations in a large-scale population study, I will address questions such as How do arctic populations differ from temperate populations in terms of diversity and distinctness? The study will focus on potentially unique populations of Atlantic cod including the arctic lake populations on Baffin Island and the Hudson Bay cod. Identifying unique populations and understanding the population structure will have direct implications for conservation management and recovery planning. By highlighting how arctic populations fit into a population study of a widespread species we will hopefully encourage other teams to consider work in these areas, as well as incorporating local skills and knowledge. Jean-François Lamarre PhD Candidate, Biology, Université du Québec à Rimouski Title: Indirect trophic links, migratory connectivity and seasonal interactions in High-Arctic nesting shorebirds. Understanding migratory species population dynamic and empowering conservation measures requires the study of indirect trophic relationships, of migratory connectivity and of seasonal interactions. I will cover these themes using shorebirds (waders) as focal species. Shorebirds are a group of migratory bird species presenting high conservation concerns. Most Canadian populations are considered declining and this decline is still unexplained. My goal is to look at some factors that may have a demographic impact on shorebirds, especially on a focal species: the American Golden-Plover (Pluvialis dominica). We will first establish the existence of indirect trophic lings between prey species (lemmings, geese, shorebirds) cohabiting at an arctic site. Then, we will describe American Golden-Plover space use throughout the year for several Arctic nesting populations to assess their level of migratory connectivity. Finally, we will relate plovers migration strategy (timing, speed, distance) with timing of breeding and reproductive success of individuals. It is important to shed light on factors explaining distribution and abundance of species, in the hope of assuring the conservation of Arctic biodiversity. Page 3 of 6

4 Vincent L'Hérault PhD Candidate, Biology, Université du Québec à Rimouski Title: Large carnivores ecology and their role in tundra ecosystem functioning The arctic tundra is currently experiencing environmental changes, yet ecosystem structure and functions remain poorly understood. Ecological relationships between species vary in space and time and it is necessary to study them at a large scale using multiple species. Large mammalian predators are key components of the tundra ecosystem as they share multiple trophic connections with other animals. They are good indicators of ecosystem health and yield important values (sale of furs, depredation of large herbivores) for communities. The harvesting of these furbearers by Inuit hunters provides direct access to very elusive and wide-ranging species. Built on a community-based approach involving Inuit hunters across 13 communities of Nunavut, my doctoral research emphasizes a pan-nunavut and a multi-knowledge study of the three larger mammalian predators (wolverine, wolf and grizzly bear) to better understand the tundra functioning. We collect animal carcasses to investigate health and reproductive status, diet and other parameters (age, parasitism). I specifically intend to determine regional, seasonal and multi-annual variations in the diet of large carnivores with regards to broad abundance of their main food source; the barren-ground caribou. Along this project, we promote Inuit knowledge and the sharing of perspectives as well as local participation and education of young. Brendan O'Neill PhD Candidate, Geography, Carleton University Title: Permafrost conditions and terrain stability considerations on Peel Plateau, NWT. My research examines how air temperatures and environmental factors, particularly snow and soil moisture conditions, control the duration of freezeback and resulting ground temperatures in permafrost. Permafrost temperatures are inherently linked to air temperatures, and generally decline moving northward. However, snow and soil moisture also strongly influence the freezeback of the active layer and mean annual temperatures of the underlying permafrost. Snow insulates the ground from cold air, and latent heat is released when soil moisture freezes, delaying freezeback of the active layer and limiting ground cooling in winter. Climate models predict increased precipitation in the fall, and rising winter air temperatures. This research will examine the respective influences of air temperature, snow, and soil moisture on the freezeback period and resulting permafrost temperatures, in order to investigate the impacts of climate change on permafrost terrain stability. The research takes place along the Dempster Highway on Peel Plateau near Fort McPherson, NWT. Numerous temperature sensors have been installed at different elevations and in varied terrain to capture a range of air temperatures and environmental conditions. Additionally, sensors installed beside the Dempster Highway Page 4 of 6

5 embankment will help examine permafrost degradation along the road and inform maintenance and management of northern highways. Jennifer Provencher PhD Candidate, Biology, Carleton University Title: Drivers of variation in reproductive output in a changing environment in relation to parasites and contaminants Both parasites and mercury may influence wildlife, but how these two interact to affect wildlife when they are exposed to both is still unclear, especially in an Arctic where both parasites and levels of mercury are predicted to increase and change in the coming decades. My work consists of two main parts to examine how both parasite and mercury (independently or together) affect bird during times of energetic stress (migration and breeding). The first component of my project involves working directly with hunters in northern communities to study parasites and mercury in birds during their migration as they return to the Canadian Arctic each spring. The second component of my work is consists of conducting experiments manipulating bird parasite burdens on the East Bay Island eider colony, a long term monitoring site where thousands annually nest on this small island in northern Hudson Bay. I also lead an annual marine bird dissection workshop held in collaboration with the Nunavut Arctic College in Iqaluit each year (funded by the Nasivvik Centre) where the bird we collected for research are used to provide educational opportunities for local students. Ashley Rudy PhD Candidate, Geography, Queen's University Title: Permafrost Hazards Mapping and prediction of permafrost disturbance in the Canadian High Arctic The purpose of my research is to understand landscape processes that control permafrost degradation in order to manage and minimize associated hazards. Thermokarst, active layer detachments and thaw slumps represent three primary forms of permafrost degradation that constitute a serious risk for infrastructure and have the potential to alter environmental and ecological stability in Arctic regions. My overall research objective is to design a landscape model to predict disturbance-prone areas using key physiographic controls derived from satellite imagery and geospatial modeling to efficiently produce hazard susceptibility maps. To test the validity of this approach and its applicability in different Arctic settings, I will work in three regions with contrasting geological and ecological characteristics: Eureka, Ellesmere Island, NU, Sabine Peninsula/Cape Bounty, Melville Island, NU, and Sachs Harbour, Banks Island, NT. Hazard mapping is particularly significant for the community of Sachs Harbour, where knowledge exchanges with community members have highlighted locations of special concern, known disturbances and deteriorating permafrost conditions. It is anticipated that the susceptibility maps and methodology developed in this research will contribute to hazard and risk assessment in Arctic communities and broader land management practices, particularly in a changing climate regime. Page 5 of 6

6 Emily Stewart PhD Candidate, Biology, Queen's University Title: Assessing freshwater invertebrate responses to multiple environmental stressors in the Great Slave Plains (NWT) Because of recent climate warming, the Great Slave plains and lowland region (NWT) near the communities of Kakisa and Fort Providence are experiencing substantial degradation of permafrost, resulting in substantial changes in the water chemistry and biota of lakes. In order to investigate the ecological effects of these climate-warming related stressors on aquatic ecosystems, I will be applying the interdisciplinary methods of paleolimnology to study long-term insect community shifts and associated changes in lake properties over time. Paleolimnology uses the biological, chemical, and physical information in lake sediments to track long-term ecological changes in aquatic ecosystems. The insects I will use in my research leave fossil remains in the sediments that can be retrieved and interpreted based on their species-specific environmental optima and tolerances. This research will not only yield an understanding of how these keystone insects are responding to climate-warming related changes, but will also be used to reconstruct past conditions to put recent changes in a meaningful historical context. Overall, my research will expand on our knowledge of the impacts of recent climate warming in the circumpolar region, as this is the greatest environmental threat the North is now facing. Page 6 of 6