Skip to main content
U.S. flag

An official website of the United States government

Nonadditive effects of leaf litter species diversity on breakdown dynamics in a deteritus-bases stream

Informally Refereed

Abstract

Since species loss is predicted to be nonrandom, it is important to understand the manner in which those species that we anticipate losing interact with other species to affect ecosystem function. We tested whether litter species diversity, measured as richness and composition, affects breakdown dynamics in a detritus-based stream. Using full-factorial analyses of single- and mixed-species leaf packs (1 5 possible combinations of four dominant litter species; red maple [Acer rubrum], tulip poplar [Liriodendron tulipifera], chestnut oak [Quercus prinus], and rhododendron [Rhododendron maximum]), we tested for single-species presencelabsence (additive) or species interaction (nonadditive) effects on leaf pack breakdown rates, changes in litter chemistry, and microbial and macroinvertebrate biomass. Overall, we found significant nonadditive effects of litter species diversity on leaf pack breakdown rates, which were explained both by richness and composition. Leaf packs containing higher litter species richness had faster breakdown rates, and antagonistic effects of litter species composition were observed when any two or three of the four litter species were mixed. Less-consistent results were obtained with respect to changes in litter chemistry and microbial and macroinvertebrate biomass. Our results suggest that loss of litter species diversity will decrease species interactions involved in regulating ecosystem function. To that end, loss of species such as eastern hemlock (Tsuga canadensis) accompanied by predicted changes in riparian tree species composition in the southeastern United States could have nonadditive effects on litter breakdown at the landscape scale.

Keywords

Acer rubrum, composition, detritus-based ecosystem funcitoning, Liriodendron tulipifera, nonadditive effects, Quercus prinus, Rhodendron maximum, richness, species difersity, streams

Citation

Kominoski, J.S.; Pringle, C.M.; Ball, B.A.; Bradford, M.A.; Coleman, D.C.; Hall, D.B.; Hunter, M.D. 2007. Nonadditive effects of leaf litter species diversity on breakdown dynamics in a deteritus-bases stream. Ecology, Vol. 88(5): 1167-1176
Citations
https://www.fs.usda.gov/research/treesearch/29002