PARENT SESSION
Contributed Oral Session 43: Landscape Ecology
Tuesday, August 9, 8:00 AM - 11:30 AM, Meeting Room 518 A, Level 5, Palais des congrès de Montréal
Does landscape structure affect different eastern Ontario anuran species at different spatial scales?
Dam , Amanda*,1, Fahrig, Lenore1, 1 Carleton University, Ottawa, Ontario, Canada
ABSTRACT- Many species of anurans (frogs and toads) are experiencing declines in abundance. Research suggests that landscape alteration, particularly the loss of forest and the insertion of roads in landscapes, are important factors contributing to these declines. Our objective was to determine whether landscape structure (forest amount and paved road density) affects eastern Ontario anurans at different spatial scales. This question was addressed by measuring population abundance of seven anuran species endemic to eastern Ontario at 34 ponds surrounded by landscapes of varying forest cover and road density. The amount of forest and density of paved roads within different distances of the ponds - 150 m, and 250 m to 2000 m at 250m intervals - were estimated from digitized 1: 50,000 National Topographic Data Base (NTDB) maps and the National Road Network, Canada, Level 1 maps, respectively. The relationship between abundance and landscape structure variables was determined for each species at each scale. American Toad and Northern Leopard Frog abundances were negatively related to forest cover within 150m and 2000m, respectively, while Wood Frog and Spring Peeper abundance was positively related to forest cover within1500m. American Toad was positively related to paved roads within 150m, while Gray Treefrogs, Spring Peepers, and Northern Leopard Frogs were negatively related to paved roads within 750m, 1500m, and 2000m, respectively. These results indicate that anuran abundance depends on landscape structure in different ways and scales for different species. The scale at which a species responds to landscape change appears to be related to the dispersal distance of the species. Knowledge of the distance at which landscape structure affects wildlife populations should help determine appropriate management policies to ensure preservation.
Key words: anurans, landscape, forest, road