A multidisciplinary study of fire, grazing and fire-grazing interactions on population, community and ecosystem properties will be continued on Konza Prairie, a native tallgrass prairie site in northeastern Kansas. The proposed research builds and expands upon a ten-year study of fire frequency effects on tallgrass prairie. Previous and proposed LTER efforts will continue to provide long-term data and baseline studies such as those that spawned a series of intensive short-term experiments and manipulations supported by NSF, NASA, USGS and state funds. Results from these previous studies have been incorporated into current LTER measurements and questions. The goal of the proposed research is to understand how grazing influences biotic and ecosystem processes and patterns imposed by fire frequency over the landscape mosaic, all of which are subjected to a variable (and possibly directional) climate regime. A new, landscape-level study linking surface and ground water chemistry will interface with ongoing measurements to provide a landscape emphasis to ecological research. The new focus involves topotedaphic effects and landscape interactions influencing ecological phenomena; specifically, the relationship between geomorphic patterns and ecological constraints (fire and/or grazing) from the perspective of the individual organism to the watershed level. These efforts are necessary if ecologists are to integrate their research to scales where biotic processes may adequately be incorporated with climate models. The Konza Prairie LTER research team has made important contributions on the area of atmosphere-biosphere interactions, Institutional support for this research is outstanding.