Effects of Forest Tree Species Composition on Vernal Pond Water Chemistry, Decomposition, Primary Productivity and Amphibian Larval Fitness Traits

Human activities have dramatically changed the composition of tree species in North American forests. These changes have altered the composition of leaf litter in woodland ponds, which has been linked to the decline of amphibian populations. Leaves from different species of trees that accumulate in ponds each fall differ in their chemical composition and produce species-specific effects on water chemistry, nutrient availability and rates of decomposition that ultimately affect the fitness (growth, development and survival) of amphibian larvae that develop in these ponds. These findings have been based on artificial pond research. This project aimed to show that the composition of trees (species, size, and number of individual trees) surrounding temporary woodland ponds directly affected the chemical characteristics (pH, dissolved oxygen, conductivity, and phenolic concentration) and rates of decomposition of the aquatic pond environment. Documenting this relationship in natural pond communities will provide an impetus for developing forest management practices that benefit amphibians and other organisms that live in these aquatic environments. We found that high levels of red maple had a positive correlation with polyphenol levels, as well as a negative correlation with pH and conductivity levels. Elms showed to have a relationship with the decomposition rates of ponds. These each could be associated with the variation in juvenile tadpole mass at metamorphosis.