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APPENDIX Current International and National Programs The six questions identified in this report provide a framework for under- standing how the national U.S. Global Change Research Program (USGCRP) re- lates to international global change initiatives and to current research programs by national agencies. Summarized here are the current activities of federal agencies in the USGCRP as they relate to the six questions specified in the report, indicat- ing which agencies are addressing each question and the foci within Global Change and Terrestrial Ecosystems (GCTE), as well as the type of research they are sponsoring: observations, experiments, and modeling. 1. At the international level, study of the effects of CO2 on terrestrial ecosys- tems has been organized as focus 1 of GCTE (Table 1). At the national level, efforts to describe the terrestrial carbon cycle have been funded most prominently by the National Aeronautics and Space Administration (NASA), the National Science Foundation (NSF), and the Department of Energy (DOE). These activi- ties are tied in with modeling efforts described below. DOE and the U.S. Depart- ment of Agriculture (USDA) have funded CO2 enrichment experiments to deter- mine direct CO2 effects on plants, and the Environmental Protection Agency (EPA) is planning additional studies of such effects. DOE projects have pursued the implications of these effects by examining CO2 effects on litter quality and decomposition. Only NSF, DOE, and USDA have funded research on CO2 effects on ecosystem processes and soil-based feedbacks, the area where international planning (GCTE) suggests that the greatest uncertainty currently exists. This re- search would benefit from closer ties with modeling programs. Modeling of CO2 effects on plants has been funded primarily by DOE and USDA. NSF and DOE 45
46 THE ROLE OF TERRESTRIAL ECOSYSTEMS IN GLOBAL CHANGE TABLE 1 Major international programs and national funding agencies that currently support research related to the six major research questions addressed in this report." International Programs National Funding Agencies Research Question Observation Experiments Modeling 1. Terrestrial Carbon Cycle GCTE (foci 1, 3) NASA DOE USFS NSF NSF NSF USDA DOE USDA EPA USFS NASA 2. Trace-Gas Flux USFS IGAC (foci 2, 4, 7) NASA NSF NSF NSF EPA EPA EPA DOE NASA NOAA USDA-ARS USFS DOE NASA USDA-ARS USFS 3. Future Distribution and USFS Structure of Ecosystems GCTE (focus 2) NSF NSF NSF HDP NASA USFS DOE EPA EPA NFS NASA USGS USFS FWS 4. Ecological Complexity USFS GCEC NASA NSF 5. Biotic Regulation of NSF USFS Hydrologic Cycles BAHC NASA NSF NSF GCTE (Focus 1) USDA-ARS 6. Transport Through Aquatic USGS Systems LOICZ NASA DOE DOE NSF NASA NASA DOE NSF USGS USDA COE COE USFS USFS "Acronyms are defined at the end of the report.
APPENDIX 47 have funded modeling of the carbon cycle, and NASA, NSF, and DOE have funded additional programs in process-level modeling of the carbon cycle. USDA is beginning to implement planned research in this area. No federal program currently emphasizes interactive effects of CO2 and other factors, although sev- eral have discussed plans to do so. 2. Trace-gas flux studies at the international level are organized under the aegis of the International Global Atmospheric Chemistry (IGAC) project. At the national level, there has been a recent upsurge in efforts to describe patterns of trace-gas flux, funded by NASA, NSF (ecosystems and atmospheric chemistry programs), EPA, the National Oceanic and Atmospheric Administration, DOE, and USDA. Experimental work has been more limited. EPA, DOE, and NSF have funded soil-warming experiments, with NASA support for students. The USDA and NSF ecosystems programs have funded experimental studies of the response of trace-gas flux to soil nitrogen status. NASA, USDA, and EPA have instituted a series of projects on trace-gas fluxes and land-use change in the trop- ics. These will complement IGAC atmospheric chemistry missions. To date, there has not been adequate manipulative studies of the effects of soil drainage, soil nutrient status, land-use change, and disturbance frequency on trace-gas flux. Modeling studies have been funded primarily by NASA, EPA, and NSF. 3. At the international level, future ecosystem structure and distribution have been the major concern of focus 2 of GCTE, which will approach this question through modeling studies. There has been substantial NSF funding for descrip- tive studies of how community structure has changed in the past in response to events such as El Nino, invasions, and successional development. NASA and EPA have also funded descriptive studies focusing on the current relationships between ecosystem processes and structure. Development of models that repre- sent these relationships predictively is beginning in ways that can permit model validation by remote sensing. The National Park Service, U.S. Geological Survey (USGS), Fish and Wildlife Service, and USDA have all traditionally performed extensive surveys and conducted observational programs on the natural history and abundances of wildlife populations. These studies have provided invaluable data on the natural variability in ecosystem structure and function and its ties to fluctuations in plant and animal abundances. Such observations have naturally led to experimental studies, largely sponsored by NSF. The NSF population biol- ogy, ecology, and ecosystems (Long-Term ecological Research [LTER]) programs have funded many plant and animal removal experiments on land, and the NSF biological oceanography program has funded comparable experiments in the ma- rine intertidal zone. NSF has also funded population-based forest modeling stud- ies. Additional modeling studies of future ecosystem structure have been funded by NASA, DOE, and EPA, and related ecosystems research has been conducted by the Department of the Interior. Most observational and experimental studies of species interactions, sponsored primarily by NSF, have been oriented toward theo-
48 THE ROLE OF TERRESTRIAL ECOSYSTEMS IN GLOBAL CHANGE retical questions of population and community ecology. The challenge in the future is to link these to predictions of global change. 4. Relatively little effort has been made at either the international or the na- tional level to understand the functional role of ecological complexity. At the international level, this complexity will be the subject matter of the Global Change and Ecological Complexity focus of GCTE, but a program has yet to be formu- lated. The Scientific Committee on Problems of the Environment is currently planning a meeting to synthesize such information. At the national level, descrip- tive studies have been funded by NASA and NSF, with a few experimental studies by NSF. 5. Biotic interactions and the hydrologic cycle are being examined at the international level by Biospheric Aspects of the Hydrological Cycle and GCTE (focus 1). At the national level, efforts to describe the biotic role in the hydrologic cycle have included studies funded and planned by NASA (e.g., First Interna- tional Satellite Land Surface Climatology Field Experiment, Boreal Exosystem- Atmosphere Study), as well as studies by USDA, USGS, and other agencies to elucidate the impacts of management and soil and vegetation characteristics on watershed hydrology and on surface water and energy balance. 6. Transport from terrestrial to aquatic systems and to the marine coastal zone is being examined at the international level by Land-Ocean Interactions in the Coastal Zone. Observational work has been funded nationally through the geosciences program at NSF and the DOE-funded Response, Resistance, Resil- ience, and Recovery from Disturbance (R4D) program in the Arctic. In addition, monitoring programs by USDA, USGS, and the Corps of Engineers (COE) have provided information on stream and river runoff. Experimental work has been funded by DOE (the R4D program), NSF (Hubbard Brook and the LTER pro- grams), USDA (e.g., Hubbard Brook and Coweeta), and COE. Modeling has been funded by DOE, NASA, and USDA.