HR: 09:00h
AN: NB41B-03    [Abstracts]
TI: Effects of Leaf Litter Species Diversity on Decomposition in a Forested Watershed in the Southern Appalachians, USA
AU: * Kominoski, J S
EM: jkominos@uga.edu
AF: Institute of Ecology, University of Georgia, Athens, GA 30602 United States
AU: Ball, B A
EM: bball@uga.edu
AF: Institute of Ecology, University of Georgia, Athens, GA 30602 United States
AU: Pringle, C M
EM: cpringle@uga.edu
AF: Institute of Ecology, University of Georgia, Athens, GA 30602 United States
AU: Hunter, M D
EM: mdhunter@uga.edu
AF: Institute of Ecology, University of Georgia, Athens, GA 30602 United States
AU: Coleman, D C
EM: davec@uga.edu
AF: Institute of Ecology, University of Georgia, Athens, GA 30602 United States
AB: Decomposition of leaf litter influences nutrient cycling and energy flow in terrestrial and aquatic ecosystems. Diversity of decomposing leaves in streams is a function of riparian plant composition and temporal and spatial heterogeneity. Leaf species have different decay rates, and leaf litter input to streams varies seasonally. Leaves with decreased lignin, lower phenolics, and lower C:N:P typically exhibit faster rates of decay and are more bioaccessible. Our collaborative project at Coweeta Hydrologic Laboratory, North Carolina, compares leaf litter decomposition in a stream and riparian zone. We selected four leaf litter species representing a gradient of resource qualities and decay rates to develop a 2 x 2 factorial design with 15 species combinations. We examined effects of species diversity and time on leaf litter decay rate (k), phytochemistry, and microbial and macroinvertebrate colonization. Results for in-stream leaf litter indicate a positive, non-additive effect of species diversity on k. AFDM remaining of mixed and single species packs was unpredictable. Defense (e.g., phenolics) and structural (e.g., fiber) compounds varied in single and mixed species packs throughout decay; however, leaf packs with Rhododendron maximum had significantly less associated fungal biomass than all other single and mixed species packs (p < .0001).
DE: 9810 New fields (not classifiable under other headings)
DE: 9901 NABS Student Award - Basic Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly