PROGRAM TITLE: Temperate and Tropical Forest Canopy Biology ACTIVITY STREAM: Process Studies SCIENCE ELEMENT:Ecological Systems and Dynamics SMITHSONIAN INSTITUTION SMITHSONIAN ENVIRONMENTAL RESEARCH CENTER Tropical Research Institute SCIENTIFIC MERIT: Understanding the dynamics of forest ecosystems is essential to the success of the U.S. Global Change Program. However, forest canopy research is seriously hindered by the difficulty of routine access. The Smithsonian Institution plans to add to its successful operation of a crane in Panama that studies tropical canopy ecology with similar equipment at the Smithsonian Environmental Research Center in Maryland. Both programs will allow direct comparison of tropical and temperate forest with regard to important global change processes. Each crane would allow scientists access to 5 acres of canopy, and a horizontal jib would be able to move a research gondola with loads of up to a ton, and lower it to any elevation. Gondola location can be located within x-y-z coordinates, and in such a manner, day and night research could be performed. The research would include such varied items as chambers for maintaining altered atmospheric composition around tree branches, and micrometeorological instruments for calculations of turbulent canopy/atmospheric gas exchanges. The research facility in Maryland would be modeled after that in Panama, and operated as a resource for visiting scientists, as much as with a telescope or submarine. Support personnel would be available to handle scheduling and continuous operation. Dual cranes would permit for the first time, detailed studies of gas-exchange processes in the temperate and tropical forest canopies, one of the most important global interfaces between the biosphere and atmosphere. STAKEHOLDERS: The activities of this program are closely related to the objectives of the Global Change and Terrestrial Ecosystems projects of the IGBP. The United Nations Environment Program has expressed strong interest in collaborating with the program in Panama. SERC is cooperating with NOAA scientists from the Atmospheric Resources laboratory in the micrometeorological aspects of the study. The development and operation of the tidal marsh CO2 enrichment chambers was funded by DOE. Plant physiology at STRI has been done in conjunction with USDA/USFS. POLICY RELEVANCE: The research conducted with these facilities will contribute broadly to three of the integrating themes of the global change program: global water and energy, global carbon cycle, and ecological systems and population dynamics. In particular, the role of forest ecosystems as governing regional fluxes of CH4, CO2, SO2, and N2O will be studied, especially the role of plant mechanisms that fix CO2. Interannual correlations between ecosystem processes and climatic variables in both forest sites contributes to the study of ecological systems and population dynamics. Overall, the question of sensitivity of forest species to climatic variability is the primary driver of this research. PROGRAM CONTACTS:SI SGCR Representative: Ted A. Maxwell NASM MRC 315 Smithsonian Institution Washington, D.C. 20560 202 357 1424 FAX: 202 786 2566 Email: tmaxwell@ceps.nasm.edu Bureau Representative: David Correll Smithsonian Environmental Research Center Box 28 Edgewater, MD 21037 301 261 4190 FAX: 301 261 7954