Graduate Theses & Dissertations

Linking Inuit and Scientific Knowledge and Observations to Better Understand Arctic Char (Salvelinus alpinus (L.)) Community Monitoring
Arctic Char (Salvelinus alpinus (L.)) have been, and remain, an important subsistence resource for the Inuvialuit, the Inuit of the western Canadian Arctic. The effects of climate variability and change (CVC) in this region have been noticeably increasing over the past three decades. There are concerns as to how CVC will affect Arctic Char and the Inuvialuit who rely on this resource as they will have to adapt to changes in the fishery. Community-based monitoring, is an important tool for managing Arctic Char. Therefore, my dissertation focused on the central question of: Which community-based monitoring factors and parameters would provide the information needed by local resources users and decision-makers to make informed choices for managing Arctic Char populations in light of CVC? This question is investigated through an exploratory research approach and a mixed method research design, using both scientific and social science methods, and quantitative (scientific ecological knowledge and observation) and qualitative (Inuvialuit knowledge and observation) information. It is formatted as three journal manuscripts, an introduction, and an integrative discussion. The first manuscript examines potential habitat parameters for monitoring landlocked Arctic Char condition in three lakes on Banks Island in the Inuvialuit Settlement Region. The second manuscript examines potential local environmental parameters for monitoring landlocked Arctic Char growth in the same three lakes. The third manuscript investigates aspects of Arctic Char community-based monitoring programs (CBMP) in the Canadian North that have led to the sustained collection of useful data for management of the resource. This dissertation makes contributions to the field of research by demonstrating the utility of a mixed methods approach. The results demonstrate similarities and differences in char growth and condition within and among Capron, Kuptan and Middle lakes on Banks Island. This supports both lake-specific and regional climate-driven changes, meaning both lake habitat and local environmental monitoring parameters should be used in char CBMP. The investigation of char CBMP across northern Canada demonstrates that an adaptive monitoring approach is important for subsistence fisheries, as changing lifestyles and environmental changes impacting a fishery can have direct effects on the successful operation of char CBMP. Author Keywords: Arctic Char, community-based monitoring, environment, Inuit Knowledge, mixed methods, Traditional Knowledge
Dynamics and Mechanisms of Community Assembly in a Mined Carolinian Peatland
Theoretical work on community recovery, development, stability, and resistance to species invasions has outpaced experimental field research. There is also a need for better integration between ecological theory and the practice of ecological restoration. This thesis investigates the dynamics of community assembly following peat mining and subsequent restoration efforts at Canada's most southerly raised bog. It examines mechanisms underlying plant community changes and tests predictions arising from the Dynamic Environmental Filter Model (DEFM) and the Fluctuating Resource Hypothesis (FRH). Abiotic, biotic and dispersal filters were modified to test a conceptual model of assembly for Wainfleet Bog. Hydrology was manipulated at the plot scale across multiple nutrient gradients, and at the whole bog scale using peat dams. Trends in time series of hydrological variables were related to restoration actions and uncontrolled variables including precipitation, evapotranspiration and arrival of beaver. Impacts of a changing hydrology on the developing plant community were compared with those from cutting the invasive Betula pendula. Transplanting experiments were used to examine species interactions within primary and secondary successional communities. Seedlings of B. pendula and the native Betula papyrifera were planted together across a peat volumetric water content (VWC) gradient. Impacts of beaver dams were greater than those of peat dams and their relative importance was greatest during periods of drought. Cutting of B.pendula had little effect on the secondary successional plant community developing parallel to blocked drains. Phosphorus was the main limiting nutrient with optimum levels varying substantially between species. Primary colonisers formed a highly stable, novel plant community. Stability was due to direct and indirect facilitative interactions between all species. Reduction in frost heaving was the major mechanism behind this facilitation. Interactions within the secondary successional community were mostly competitive, driven by light and space availability. However, restricted dispersal rather than competition limited further species recruitment. Predictions based on the DEFM were partially correct. A splitting of this model's biotic filter into competition and facilitation components is proposed. There was little support for the FRH based on nutrient levels and VWC. B. pendula had higher germination and growth rates, tolerance to a wider range of peat VWCs and a greater resistance to deer browsing than native birch. Peat mining, combined with restoration actions and the arrival of beaver has moved much of the bog back to an earlier successional stage circa 350+ years BP. Evidence points to B. pendula being a "back-seat driver" in the ecosystem recovery process. Indirect facilitation of a native by an exotic congener, mediated through herbivory, has not been described previously. Shifts in relative contributions of facilitation, competition and dispersal limitations to community assembly may be useful process-oriented measures for gauging progress in restoration. Author Keywords: Betula pendula, community assembly, competition, facilitation, peatland, restoration

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