PARENT SESSION
Contributed Oral Session 17: Reptiles and Amphibians: Habitat; and Communities
Monday, August 8, 8:00 AM - 11:30 AM, Meeting Room 524 B, Level 5, Palais des congrès de Montréal
Relating local and landscape habitat features to anuran distributions: what scale is most appropriate?
Browne, Constance1, Foote, A.2, Paszkowski, Cynthia1, 1 Department of Biological Sciences, Edmonton, Alberta, Canada2 Department of Renewable Resources, Edmonton, Alberta, Canada
ABSTRACT- Habitat alteration is suggested to be the greatest threat to amphibian populations; however, the habitat requirements of many species are poorly known. Requirements must be identified in order to create management plans to preserve/restore amphibian habitat. We examined the relationship between amphibian species presence and habitat features for 24 ponds in Alberta's boreal forest. Our goals were to determine (1) which habitat features are associated with breeding and rearing habitat of wood frog (Rana sylvatica), chorus frog (Pseudacris maculata), and western toad (Bufo boreas), (2) whether local pond habitat features or landscape features are more important in controlling distributions of these three species, and (3) at what scale landscape features are most important for controlling distributions. Our work was part of a multi-disciplinary project by the HEAD (Hydrology, Ecology, And Disturbance) research group. HEAD has collected data on biotic (e.g., submersed vegetation) and abiotic features (e.g., geomorphology, hydrology, limnology) of the 24 study ponds. A project goal of HEAD is to be able to predict the response of individual wetlands to disturbances using a Geographic Information System (GIS)-based Decision Support System (DSS). We conducted amphibian surveys at the 24 HEAD ponds from May to August 2004 including measures of occupancy and reproductive activity. Wood frogs, chorus frogs, and western toads were found at 24, 23, and 17 of the 24 ponds, respectively, with successful breeding at 18, 4, and 6 ponds. Measures of woody debris, terrestrial and aquatic vegetation, fish, invertebrates, pond physical characteristics, and water chemistry were used to describe local habitat features. Landscape variables included distance to nearest road, oil pad, cut line, and water body. The percentage of highly disturbed areas (roads and oil pads), cut lines, wetlands, and different vegetation types were estimated at different buffer widths around each pond (e.g. 50, 500, 5000 m) and analyzed to identify the scale at which landscape features were important to anurans.
Key words: amphibian, habitat use, landscape, scale