|HOME SCHEDULE AUTHOR INDEX SUBJECT INDEX|
Protozoan activity in leaf litter decomposition.
Adl, Sina*,1, Hunter, Mark 2, Coleman, David2, 1 Department of Biology, Halifax, NS, Canada2 Institute of Ecology, Athens, GA, USA
ABSTRACT- Decomposition of litter requires the digestive action of primary saprotrophs and fragmentation by detritivores. With time, the litter becomes a spongy matrix that provides a habitat for a diverse microbial community. We asked whether the Protozoa were numerically significant in this matrix, and whether they could have a significant role in nutrient recycling during leaf litter decomposition. New leaf litter was placed on the forest floor in litter bags, and followed 12 months. Three types of litter representing slow (Rhododendron maximum), medium (Quercus prinus) and fast (Liriodendron tulipifera) decomposing species were chosen. The experiment was replicated and conducted in parallel at Luquillo (Puerto Rico) with slow (Bachanavia capitata), medium (Dacryodes excelsa) and fast (Guarea guidonia) species. Litter bags (in triplicate) were retrieved at 3 month intervals and the micro-organisms were extracted. The organisms were enumerated and categorized for statistical analysis. The remaining litter from samples was used for chemical extraction and composition analysis. The results indicate trends that correlate with litter chemistry changes and with seasonal succession. The effect of seasonal changes on the protozoan assemblage were less evident at the tropical site, where litter chemistry changes with decomposition had a more pronounced effect on protozoan succession. We discuss both methodological aspects of the experiment and results of the correlations.
Key words: litter decomposition, soil ecology, protozoa, community structure