PROGRAM TITLE: Chesapeake Bay Global Change Research ACTIVITY STREAM: Process Studies SCIENCE ELEMENTS:Ecological Systems and Dynamics Biogeochemcial Dynamics Climatic and Hydrologic Systems SMITHSONIAN INSTITUTION SMITHSONIAN ENVIRONMENTAL RESEARCH CENTER (SERC) SCIENTIFIC MERIT: The SERC Rhode River site is an ideal location for long- term interdisciplinary studies of the impact of global change on the environment. This facility has been selected through national peer competition as one of a network of 25 sites best suited for global change ecological research in the United States. These are research centers in the United States with site characteristics, facilities, staff, and long-term research results which make them ideal for ecological aspects of global change research. The objectives of this program focus on long-term monitoring of biological populations and their controls; the effects of land use on hydrology, nutrient dynamics, and biotic populations; the direct effects of increasing atmospheric carbon dioxide concentrations on plant communities and the atmosphere; UVB monitoring both in the Chesapeake region and globally; data management and ecological modeling at various hierarchical levels from populations through landscapes. Long-term measurements at permanent stations and comparative regional studies are used to detect change and extrapolate local site data to the regional level. Up to 20 years of continuous monitoring data are now available on a wide range of biological and physical/chemical parameters. Experimental approaches are often used to test for effects of projected change. For example, chambers are enriched with carbon dioxide continuously to examine direct physiological and ecological effects. New technology is tested and adapted to ecological research needs. For example, a tuneable infrared diode laser is being used to continuously measure turbulent exchange rates between mature hardwood forest canopies ad the atmosphere. The ARC INFO GIS is used to create landscape level data bases for regional models for land use/nutrient dynamics and various simulation models are used to synthesize data on individual ecosystem behavior. Where necessary new instruments are developed and calibrated by SERC. For example, UVB spectral radiometers designed for continuous, high precision monitoring of spectral data under ambient conditions. A new in situ ozone monitoring instrument is now under development for use in the forest exchange studies. STAKEHOLDERS: The program involves close cooperation with agencies such as NSF, DOE, NOAA, NCAR, Maryland Department of the Environment; universities such as Maryland, Johns Hopkins, William and Mary and George Mason; SI bureaus such as STRI, NMNG, NZP. The program contributes broadly to USGCRP integrating themes such as global water and energy, global carbon cycle, and ecological systems and population dynamics. It is closely tied to the goals of IGBP Core Programs such as LOICZ and GCTE. POLICY RELEVANCE: The studies conducted under this program are directly focussed on high-priority objectives of the USGCRP, including long-term documentation of the threatened estuarine and coastal ecosystems, long-term environmental monitoring and measurement of atmosphere-ecosystem relationships, and development of predictive models for atmosphere- ecosystem interactions and land use effects on nutrients and hydrology. They look at some of the most critical aspects of ecological systems and dynamics, of biogeochemical dynamics, and of solar influences (UVB irradiances). 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