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Permafrost Thaw-Induced Forest To Wetland Conversion: Potential Impacts On Snowmelt And Basin Runoff In Northwestern Canada, Emily Haughton Jan 2018

Permafrost Thaw-Induced Forest To Wetland Conversion: Potential Impacts On Snowmelt And Basin Runoff In Northwestern Canada, Emily Haughton

Theses and Dissertations (Comprehensive)

In the discontinuous permafrost zone of northwestern Canada, snow covers the ground surface for over half the year, thus snowmelt constitutes a primary source of ecosystem moisture supply and strongly influences stream hydrographs. The peat landscapes along the southern limit of discontinuous permafrost are dominated by forested permafrost plateaus (“forest”), and treeless, permafrost-free wetlands (“wetland”). Permafrost-thaw induced transformation of this landscape has changed water flow and storage processes and therefore introduced new uncertainties on the region’s water futures. Here, I a) characterize forest and wetland water storage and flow from snowmelt, and b) evaluate how permafrost thaw-induced wetland expansion at …


The Effects Of Fire On Snow Accumulation, Snowmelt And Ground Thaw On A Peat Plateau In Subarctic Canada, Elyse Mathieu Jan 2018

The Effects Of Fire On Snow Accumulation, Snowmelt And Ground Thaw On A Peat Plateau In Subarctic Canada, Elyse Mathieu

Theses and Dissertations (Comprehensive)

During the past century, the highest rates of warming have occurred at latitudes above 60oN, where air temperatures have risen at twice the rate of other regions. In northwestern Canada, this warming has coincided with an increase in the frequency, size and severity of wildfires. The influence of such fires on the trajectory of on-going permafrost thaw is not well understood. As a consequence, the combined impacts of climate warming induced permafrost thaw and possible feedbacks arising from wildfires cannot be properly assessed. This study examines the impact of a 2.7 ha low-severity wildfire (July 2014) on water …


Landscape Scale Spectral-Temporal Modelling Of Bamboo-Dominated Forest Succession Within The Atlantic Forest Of Southern Brazil, Clara Greig Jan 2018

Landscape Scale Spectral-Temporal Modelling Of Bamboo-Dominated Forest Succession Within The Atlantic Forest Of Southern Brazil, Clara Greig

Theses and Dissertations (Comprehensive)

Tropical and subtropical ecosystems have become vulnerable to biological invasion (i.e., bamboo) due to human induced forest fragmentation. Bamboo ecological processes have been found to impede forest development, resulting in a state of arrested succession, which has been found to significantly reduce biodiversity, thus contributing to biotic homogenization. In this study we use a semi-empirical approach to develop a community-level spatially explicit ecological process model (hybrid model) using a time-series of Landsat imagery to describe single-landscape scale ecological processes of a pervasive bamboo species (Merostachys skvortzovii) found throughout the Araucaria forest, a critically threatened subtype of Atlantic forest …


Spatial Modelling And Wildlife Health Surveillance: A Case Study Of White Nose Syndrome In Ontario, Lauren Yee Jan 2018

Spatial Modelling And Wildlife Health Surveillance: A Case Study Of White Nose Syndrome In Ontario, Lauren Yee

Theses and Dissertations (Comprehensive)

Wildlife data is often limited by survey effort, small sample sizes, and spatial biases associated with collection and missing data. These factors can create unique challenges from a surveillance perspective when trying to extract spatial patterns of habitat suitability and disease distributions for conservation and management purposes. This thesis examined data quality from a wildlife health database in the context of spatial analysis of wildlife disease. Spatial analysis of the data to predict habitat suitability of bats and white nose syndrome afflicted bats was examined by using the MaxEnt modelling method. Methods to reduce spatial bias were examined and specific …