LE3 .A278 1999

1999

Taylor, Phil

Acadia University

Master of Science

Masters

Biology

Biology

I examine the effects of landscape structure on the incidence and abundance of yellow-spotted salamanders, Ambystoma maculatum, and use these population level responses as indirect measures of movement. Two surveys of breeding populations in ponds located in a heterogeneous landscape were conducted and effects of landscape structure assessed at multiple spatial scales. Landscape structure was quantified as the proportion of forest and the total length of roads surrounding ponds. Additionally, the movement capabilities of juvenile A. maculatum in different habitat types was explored. Through the first survey I show that the proportion of forest influences incidence and density at a small spatial scale (100 m). I conclude that the breeding and post-breeding migration movements are influenced by the amount of forest and identify 15% forest, within 100 m of the pond, as a threshold amount of forest below which A. maculatum cannot persist at a pond. Results from a second survey, which encompassed a greater number of ponds at broader spatial scales, concur with the previous survey for the small scale effects of the proportion of forest, however, there is a significant effect of the proportion of forest at a broad spatial scale (1000 m). This provides indication that populations are spatially structured and that the amount of forest increases the connectivity of the landscape for A. maculatum. Also, at small spatial scales the total amount of road has a negative effect on incidence and abundance. Experimentally I assess the rates of movement of juveniles in forested and field habitat. Results show that juveniles can move faster in field habitat than forest. Finally, I explore the possibilities of harmonic radar as a new technique for tracking juvenile A. maculatum.

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