9602572 Dodds Dr. Walter Dodds, Division of Biology, Kansas State University, and Dr. Barry Biggs, National Institute of Water and Atmospheric Research (NIWA), Christchurch, New Zealand will conduct collaborative research in New Zealand on the metabolism of stream algae. Mixed assemblages of microorganisms (biofilms or periphyton) coat surfaces in streams and rivers. These assemblages are generally the main energy source for higher trophic levels in unshaded temperate region streams. In stable-flowing, enriched streams periphyton can proliferate causing water management problems. Dr. Barry Biggs and his co-workers have characterized extensively the periphyton communities and associated land use practices in a large number of the highly diverse streams and rivers in New Zealand and have established the best empirical model of factors controlling periphyton biomass and composition from any area in the world. New Zealand provides an outstanding natural laboratory because heterogeneity of geological, climatic and human use is extreme and occurs over very small spatial scales (a few 100 km) relative to typical continental areas. Dr. Dodds will link the unique data of his counterpart to small scale metabolic measurements made with flow, light and O2 microprobes and use this information to create a predictive mechanistic model of stream biofilm metabolism for the different community types. This model will provide a basis for more general models of stream ecosystem function. Such models are needed to assess responses of stream water quality and ecosystem function to human disturbance.
