Effects of Low pH and Other Chemical Variables on the Local Distribution of Amphibians

Abstract

mortality caused by low pH could be responsible for the absence of the two least tolerant species from acidic ponds. Hatching of embryos of R. sylvatica was not related to pond pH while mortality of embryos of A. jeffersonianum increased significantly as pond pH declined. H. andersoni also hatched in all experimental New Jersey ponds, but embryos of B. woodhousei suffered significantly higher mortality in ponds of lower pH's. Hatching success was variable at specific pond pH's, indicating significant interaction of pH with other chemical variables. In laboratory trials, tadpoles of B. woodhousei and H. andersoni grew significantly slower when exposed to low pH. This sublethal effect on body size has important implications for dynamics of amphibian populations in acidic ponds.