Linking Ecosystem Processes and Community Structure Along Salinity and Nutrient Gradients In Tropical Marshes

University Of California-Davis, Davis CA

Investigators

Abstract

Abstract 00-889211 Rejmankova Linking ecosystem processes and community structure along salinity and nutrient gradients in tropical marshes Accelerated land use change in the tropics is increasing nutrient loading to aquatic ecosystems. This is resulting in changes in species composition and ecosystem functions such as primary production and nutrient cycling. The aim of this research is to obtain a mechanistic explanation for an ecosystem level response to increased nutrient input along a salinity gradient. Dr. Rejmankova and colleagues propose that there is a context (salinity) dependent switch between phosphorus (P) and nitrogen (N) limitation in tropical marshlands. This project will use P-limited wetland ecosystems in Belize as a model system on which to document how nutrient limitation can be shifted along a salinity gradient through different constraints on individual components of plant communities. A short-term mesocosm experiment will evaluate response of individual marsh components to different levels of salinity, P and N. A long-term experiment involving additions of nutrients to a replicated set of marshes of different salinity will verify the predictions of the ecosystem-level response. In addition to the intellectual merit of a better understanding of these ecosystems, the project has immediate relevance to conservation of wetlands, and may provide data that will be relevant to malaria control in Belize.