Environmental sensor networks are an essential part of long-term ecological research and environmental monitoring systems. Maturing technologies for wired and wireless sensors and sensor platforms, for web-services and service oriented architectures, for dynamic real-time data grids, and for semantic data integration and work flow architectures are now converging to create outstanding opportunities for utilizing sensor networks for environmental research. This collaborative project will establish a working group of environmental researchers and technologists from the U.S. and Latin America, to evaluate the end-user (i.e. scientists' and students') software requirements of a planned environmental sensor network at the Organization for Tropical Studies' La Selva Biological Station, a rain-forest site in northeastern Costa Rica. The working group will be comprised of active tropical ecologists, computer scientists, and informaticists with professional interests in utilizing sensor networks for environmental research and education. A usability engineer will organize the year-long, user-centered, effort and will facilitate a structured research process to produce a comprehensive requirements analysis as a web-accessible and published report. This timely effort will continue an international collaboration among a working group of U.S. and Latin America environmental biologists and network technologists, started by the PIs in 2005. It has the specific aim of increasing utilization of sensor networks and their connections to contribute to the availability of global environmental data.