Red maple dominance enhances fungal and shredder growth and litter processing in temporary ponds

Abstract

We used in situ and laboratory mesocosm experiments to test the effects of red maple (Acer rubrum), white oak (Quercus alba), and northern red oak (Q. rubra) leaf litter on microbial biomass and detritivore (Limnephilus indivisus) growth, survival, and organic matter processing in temporary forest ponds. Fungal biomass was highest in red maple leaf litter but was reduced in both maple and oak litter by detritivore presence, indicating a foraging preference based on fungal biomass. Organic matter processing and fine particulate organic matter (FPOM) generation rates were highest in red maple treatments containing detritivores, and red maple diets allowed for rapid larval growth and development to adulthood, while oak diets (Q. alba or Q. rubra) resulted in slower development and increased mortality of larvae. Red maple dominance around pond margins may have positive effects on detritivore growth and generation of FPOM in temporary ponds. Because many of the organisms that feed on FPOM also serve as prey for larval amphibians, the effects of increased FPOM production resulting from red maple dominance may travel through the food web to affect higher trophic levels.