Redistribution and decomposition of leaf litter as affected by understory and slope direction in a temperate mixed hardwood forest

Lee*, D., E.-J. Park, S.-H. Kim, Gayoung. Yoo, and H.-J. Lee

Department of Environmental Planning, Graduate School of Environmental Studies, Seoul National University, Seoul 151-742, South Korea

Telephone : +82 2 880 5650

Fax : +82 2 873 5109 or +82 2 887 6905

email : leedw@plaza.snu.ac.kr

Abstract

Redistribution and decomposition of leaf litter were investigated in a temperate mixed hardwood forest and related to understory and slope direction. Colored papers were placed on slopes and traced to understand pattern of litter movement. The results suggested that dwarf bamboo, an evergreen shrub, (Patch SS) trapped the leaf litter and retarded their movement in the southwest-facing slope with that species present. Moreover, leaf litter was more dispersed in the southwest-facing without dwarf bamboo (Patch S) than in the northeast-facing slopes without the species (Patch N). The colored papers were not simply slid downslope. Rather, some of those, especially placed in Patch S moved upward, suggesting that leaf litter is dominantly driven by valley wind. Decomposition rates were different among the leaf litter species. Decay constant of Quercus mongolica was significantly (p < 0.05) lower than those of Kalopanax pictus and Acer pseudosieboldii in Patch N and S. Decomposition rate of Q. mongolica was lowest in Patch S, however other two species had the lowest decay constants in Patch SS. The difference in decay constants between patch N and S were not significant. It means that understory may have more effects on decomposition process of leaf litter than slope direction in a small scale area. In summary, understory and slope direction can have a great effect on litter redistribution and decomposition. So it is suggested that in order to reduce organic residue and nutrient losses from forest ecosystems situated on slopes and subjected to strong wind during fall and winter, removal of understory should be minimized.