PROGRAM TITLE: Paleoecological Effects of Climate Change ACTIVITY STREAM: Observations SCIENCE ELEMENT:Earth System History Ecological Systems and Dynamics Human Interactions SMITHSONIAN INSTITUTION NATIONAL MUSEUM OF NATURAL HISTORY (NMNH) SCIENTIFIC MERIT: The objectives of this program are to understand natural rates of environmental change, to detect the effects of past environmental and climatic changes on ecological systems, to examine previous episodes of warm climate (e.g. the early Eocene warm interval), to test the predictions of computer simulations of paleoclimate, to establish pre- human baseline conditions, and to extract general rules of ecosystem response to sudden environmental change. This program will include phases related to observation (data gathering on fossils, sediments, stable isotopes), understanding (data analysis and theory testing), and data systems (development of computer systems to assist in organizing, archiving, analyzing, and preserving data on the history of global change). The program also will be gathering data critical to testing models developed by those involved in prediction activities. To meet our goals we will be focusing on warm intervals in earth history, times of major and sudden environmental/climatic change, and pre/post human comparisons. Our understanding of long-term behavior of ecosystems in response to climatic change is very weak, as is our knowledge of pre-human baseline conditions. We also need a stronger proxy record of paleoclimate against which to test computer simulations of climate. Data will be maintained in both individual database systems and in larger communal databases. Information relating to fossil collections is maintained in a NMNH-wide system. Data and inferences on terrestrial systems will be included in a customized research data management program linked to graphics/map interface. This database will be shared with collaborating scholars at private and governmental research institutions. The program was established in FY 1987 by Smithsonian Trust Funds as the "Evolution of Terrestrial Ecosystems," and as a federal line item in FY 1988, but components of the program have existed for much longer as individual research efforts. Research plans and protocols already exist and are active for all parts of the program. The Museum of Natural History houses collections and field data, and provides laboratory and office space. Studies of the early Eocene warm interval, Paleozoic peat swamp communities, Holocene coral reef histories, and the pre/post human faunas of the Hawaiian islands are already underway. Data gathering and analysis for these studies continues in Colorado, Hawaii, Illinois, Indiana, Kentucky, Wyoming, and around the Caribbean basin. We have produced numerous research articles in refereed journals documenting such things as the effect of sea-level rise on coral reef growth, pre-historic human colonization on island biotas, climate change on vegetational diversity and structure. We have a book in press titled "Evolutionary Paleoecology of the Terrestrial Biota", that documents major episodes of climatic and ecological change on land. We have designed and implemented a custom computer data base that is linked to a map-displaying graphics interface; these allow researchers to interactively query the database while simultaneously evaluating the positions of paleoclimatic and paleobiogeographic boundaries, and the data points from which they are derived. We have established an international network of collaborating scholars at private and governmental institutions. We have sponsored and hosted international meetings, and a symposium addressing the issue of ecosystem stability on long and short time scales. We have preliminary data suggesting that past ecosystems may have displayed "threshold" effects; they showed little response to climate change over long time periods, then changed rapidly over short intervals. STAKEHOLDERS: Strong linkages to research at USGS, and other Smithsonian agencies, as well as NSF supported research being carried out at many private universities and museums. POLICY RELEVANCE: Study of "deep history" makes three unique and important contributions to global change research. One, biotic, geologic, and climate systems experience natural fluctuations over decades to 105 years, therefore only retrospective studies that consider very long time periods have a hope of distinguishing signal from noise, and of establishing pre-human baseline conditions. Two, fossils and sedimentary rocks directly record the impact of past global climate change on ecological systems, providing the only examples we have of these phenomena and their effects. Three, paleontological and geological data are the critical, and only, test of computer- based simulations of past climate conditions, and so they play an important role in refining models of climate dynamics. This program addresses most of the research priorities outlined in the GCRP under Earth System History. Paleoclimate and paleoecology are explicit foci of research, as are past changes in ocean circulation, ocean productivity, and sea level. The program will produce results relevant to subjects listed under Ecological Systems and Dynamics, particularly long-term measurement of structure/function. Paleontological data collected by this program will also be important for testing models developed by researchers operating under Climate and Hydrologic Systems. 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: Marsha Sitnik NMNH MRC 106 Smithsonian Institution Washington, D.C. 20560 202 357 2670 FAX: 202 786 2934 Email: nmhod004@sivm.si.edu