The effect of leaf conditioning on the timing of litter processing on a Michigan woodland floodplain

Abstract

This study investigated the role of conditioning in controlling the rate of microbial colonization of leaf litter (pignut hickory, Carya glabra) on a woodland floodplain and the timing of invertebrate participation in the processing of that litter. Experiments compared the rates at which the floodplain invertebrate community processed leaf litter that had been "conditioned" under circumstances expected to result in significantly different microbial densities (i.e., stream conditioned vs. floodplain conditioned). The data showed that soil invertebrates clearly processed the stream-conditioned leaves at a faster rate. Even with the relatively low soil temperatures in early spring, there was significant processing of the stream-conditioned leaves while the floodplain-conditioned leaves remained virtually untouched. This showed that the timing of invertebrate participation in the processing of floodplain litter cannot be ascribed entirely to temperature-related invertebrate inactivity. Rather, it is dependent on those internal and external factors controlling the colonization of leaves by microorganisms.