Does microorganism productivity influence macroinvertebrate richness in aquatic detritus-based communities?
Yee, Donald*,1, Juliano, Steven 1, 1 Illinois State University, Normal, Illinois, U.S.A. ABSTRACT- The food web of water-filled tree holes is an ideal system to test alternative hypotheses for relationships between productivity and species richness. Tree hole communities are dependent on exogenous inputs of detritus, which support a microorganism assemblage, which in turn supports numerous macroinvertebrate species. We conducted an 11 month field study in artificial tree holes to determine if: a) different initial inputs of detritus (senescent leaves, dead invertebrates) affect microorganism productivity and abundance; 2) the rate of subsequent input affects microorganism productivity and abundance; and 3) microorganism productivity or abundance influence richness or abundance of macroinvertebrates. We established 6 replicates of 4 initial input treatments (0.25x, 0.5x, 1x, 4x observed field detritus inputs) that were open to colonization for one month. Following that period, 2 contain
