Impacts of Shading on Larval Traits of the Frog Litoria ewingii in a Commercial Forest, Tasmania, Australia

Abstract

Removal of vegetation directly surrounding a breeding pond has the potential to significantly alter the environmental conditions experienced by larval amphibians during development and, therefore, may affect the life history of this and subsequent life stages. In this study, we investigated growth, development, and survivorship of Litoria ewingii as a result of different shading conditions in a commercially logged forest in Tasmania, Australia. We specifically investigated responses in two types of breeding ponds available to the species: permanent ponds, and smaller ephemeral ponds. Increased shading in permanent ponds resulted in reduced survival. Larval growth and development did not respond significantly to shading treatment in permanent ponds but were significantly affected by pond elevation. In ephemeral ponds, increased shading resulted in decreased developmental rate and a higher coefficient of variation for size at metamorphosis. Our findings suggest that the larval success of L. ewingii is not likely to be enhanced by vegetative buffer zones around permanent pond margins but may be enhanced by ensuring heterogeneity of shading conditions around ephemeral ponds.