Impacts of forest management practices on amphibian populations have received growing attention in the last 10 yr. However, to date, measured responses include only comparisons of species diversity indices and population counts without true spatial and temporal controls. We used an experimental approach to test for differences in growth rate, fecundity, age at maturity, and whole-body storage lipids in individual mole salamanders, Ambystoma talpoideum, placed in differently managed habitats. Four 100-m(2) field enclosures were built in each of two habitats, a 4-mo-old clearcut and an adjacent 40-yr-old pine forest. On 19 July 1994, 80 recently metamorphosed and individually marked, weighed, and measured (snout-vent length) A. talpoideum were randomly assigned to field enclosures (n = 640 salamanders). Between 31 October 1994 and 31 March 1995, salamanders were collected from the enclosures using pitfall traps. Body mass and length, whole-body nonpolar storage lipids, clutch size, and egg nonpolar lipids were determined for sexually mature salamanders. After an average of 5-6 mo exposure to clearcut and 40-yr-old pine forest, there were no significant differences between habitats for number of recaptured salamanders, final body mass, final body length, percent whole-body storage lipid, clutch size, or percent storage lipid of eggs. Our results suggest, in contrast to expectations based on many comparative studies with other species, that habitat modification resulting from clearcutting may not have detrimental effects on newly metamorphosed A. talpoideum. We contrast our experimental approach, with its strengths and weaknesses, to previous comparative studies and identify the inherent complexities involved in establishing a causal link between habitat management (clearcutting) and effects on amphibians.
Available at: http://works.bepress.com/peter_niewiarowski/2/