9306365 Minshall The importance of fine particulate organic matter (FPOM) as an energy source in streams is well documented and considerable data exist on spatial and temporal patterns of FPOM in transport and in benthic storage. Information on FPOM dynamics, including transport distance, rates of FPOM deposition and resuspension, retention time on the stream bed, the influence of varying hydraulic and geomorphic conditions, and direct determination of capture by aquatic insects, is, however, very limited. Our initial research has established the efficacy of the method and its utility for tracking the fate of natural FPOM in two turbulent streams. Using a unique method to label individual, natural particles of FPOM with 14C which enables us to recover and detect individual FPOM particles under natural stream conditions, we propose a detailed research program utilizing the developed methods to (1) quantify the dynamics of transport, deposition and resuspension of FPOM in selected streams, and (3) examine more precisely mechanism governing FPOM dynamics using experimental fumes. The techniques allows us to overcome a major impediment in advances in stream ecology by providing direct measures of transport distance and rates of capture (both biological and physical), retention, and resuspension. %%% The data from these studies will provide values for these factors over a range of geomorphic and hydraulic conditions and valuable information to test and modify some of the basic paradigms in stream ecology including the River Continuum Concept and Nutrient Spiraling Concept. We are confident that the results and methods will have broad applicability to similar studies in other ecosystems.
