Background/Question/Methods Forestry practices are implemented worldwide to manage tree populations and harvest resources. Forestry practices involve the thinning and/or intentional planting of trees which influence canopy cover and litter species. Leaf litter from different tree species play a role in pond ecosystems as a source of nutrients, refugia from predators, and a food source. When certain litter species are eliminated from or added to pond ecosystems, it can have diverse effects on ecosystem processes and pond communities, including amphibians, which are declining worldwide. To test the effects of litter species on ecosystem processes, water quality, and tadpole growth and development, we set up mesocosm tanks with five litter species: red oak, white oak, sugar maple, white pine, and prairie cordgrass. Phyto- and zooplankton inoculum and 40 gray treefrog hatchlings were added to replicate tanks of each litter treatment (20 total tanks). A diel oxygen technique was used to measure community metabolism and primary productivity throughout the study.

Results/Conclusions Size and time to metamorphosis of gray treefrogs was measured as indicators of fitness. Results indicate differences among treatments in water quality and ecosystem processes. The sugar maple and white oak treatments were consistently lower in dissolved oxygen than all other treatments. Grass and red oak had higher levels of primary productivity and community metabolism than sugar maple and white oak, with pine being intermediate in both. Differences in primary productivity could be related to concentrations of nutrients in the litter, the rate of litter composition, or both. Future data on decomposition and nutrients could determine which of these are more important. Tadpoles from the prairie cordgrass, white pine, and red oak treatments had high survival, sugar maple had intermediate survival, and white oak had the lowest survival. The low survival in the white oak tanks may be from low primary productivity or high concentrations of tannins (not measured). There was no significant difference in time to metamorphosis among treatments. Metamorphs were largest in the prairie cordgrass treatment and smallest in the pine treatment. Metamorphs from red oak, sugar maple, and white oak treatments were intermediate in size. These results indicate that forestry practices could influence water quality, ecosystem processes, and amphibian performance. Additionally, managing exclusively for white oak, particularly around ponds, may be detrimental to amphibian populations and biodiversity.