Vegetation Correlates of the History and Density of Nesting by Ross’s Geese and Lesser Snow Geese at Karrak Lake, Nunavut

Аннотация

Growth in populations of Ross’s geese (Chen rossii) and lesser snow geese (C. caerulescens) has led to concerns about destructive grazing of Arctic ecosystems. We estimated the extent and composition of plant communities at Karrak Lake, Nunavut, where populations of both goose species have grown geometrically over the past three decades. Proportion of land covered by vegetation was lower in areas where geese had nested for more than 20 years than in areas with no previous nesting history. Vegetative cover also declined with increasing nest density of both species. Species richness and diversity of vegetation was higher in more recently colonized areas of nesting than in areas with over 20 years of goose nesting. Exposed mineral substrate, exposed peat, and Senecio congestus were more prevalent in areas with a 10-year or longer history of goose nesting than in areas with less than 10 years of nesting. These patterns confirm that increasing numbers of nesting Ross’s geese and lesser snow geese have altered the spatial distribution of vegetation surrounding Karrak Lake and reduced the species richness of local plant communities.