Date of Award

8-2017

Level of Access

Campus-Only Thesis

Degree Name

Master of Science (MS)

Department

Ecology and Environmental Sciences

Advisor

Jasmine Saros

Second Committee Member

Brian Olsen

Third Committee Member

Hamish Greig

Abstract

Goose populations have been increasing globally, particularly over the last few decades, while caribou populations have been declining. Both caribou and geese rely on Arctic habitat, with geese using it as breeding grounds and summer habitat. Caribou are typically year-round residents of the Arctic, with some populations present in subArctic habitat. Little is known about the relationship between fluctuating goose and caribou populations and their impact on Arctic freshwater ecosystems. We assessed the effects of goose and caribou on a set of six Arctic lakes in southwest Greenland. Vegetation assessment and pellet density counts were conducted at each of the six lakes to determine suitable habitat. There were no significant differences between the Kellyville region and the Greenland Ice Sheet (GrIS) region for either vegetation species or pellet densities. There were however changes in species abundance with the Kellyville sites being more shrub dominated while the GrIS sites were more grass dominated. Goose and caribou pellets appeared to be older at the Kellyville lakes compared to those at the GrIS lakes which coincided with more individuals being seen at the GrIS sites. Small-scale lake experiments were also conducted to assess responses of algal biomass, and nutrient concentrations to pellet input. Algal biomass and nutrient concentrations were higher in caribou pellet treatments and highest in goose pellet treatments compared to control treatments. Additionally, these responses varied across the 6 study lakes, with the strongest responses in nutrient and algal biomass concentrations occurring in the lakes located closest to the ice sheet. Vegetation assessment and pellet density counts were also conducted at each of the six lakes to determine suitable habitat. There were no significant differences between the Kellyville region and the GrIS region for either vegetation types or pellet densities. As climate warms and goose and caribou populations fluctuate, it will be important to have a better understanding of what impacts these population changes will have on Arctic freshwater systems. With this improved knowledge we will be able to better implement management plans and preserve the Arctic habitat upon which geese, caribou and many other species rely.

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