Research Division Science & Engineering Alliance, Inc. 1522 K Street, N.W., Suite 210 Washington, DC 20005 202.842.0388 shepard@sea2.org
Dr. Larry Robinson Environmental Sciences Institute Florida A&M University 1515 Martin Luther King Boulevard, Tallahassee, Florida 32307 850.561.2760 larry.robinson@famu.edu
Dr. Teferi Tsegaye Department of Plant & Soil Science Alabama A&M University 4900 Meridian Street Normal, AL 35762 256.603.8487 teferi.tsegaye@aaum.edu
Recent analyses suggest that 83 percent of the earth’s land surface has been affected by human settlements and activities, leaving only 17 percent in wilderness . The use of phosphorus (P) fertilizers and the rate of P accumulation in agricultural soils increased nearly threefold between 1960 and 1990, although the rate has declined somewhat since that time. The current flux of P to the oceans is now triple that of background rates, approximately 22 teragrams of P per year versus the natural flux of 8 teragrams. Despite a growing body of knowledge on nutrient dynamics in terrestrial and aquatic environments, the effects of widespread land use change and climate variability on nutrient contents and cycles in the environment are not well understood .
Phosphorus dynamics due to anthropogenic activities and climate variability may trigger ecosystem responses at regional and continental scales. Nutrients, particularly P enrichment of aquatic ecosystems can result in eutrophic conditions and the accompanying changes in the biological productivity, dissolved oxygen levels, marine ecosystem biodiversity, and nutrient cycling. Increased phytoplankton production may influence atmospheric composition and, hence the hydrological cycles. As suggested by a recent study in the Southern Ocean, cloud droplet number concentration over an algal bloom was twice the amount away from the bloom and the cloud effective radius was reduced by 30%.
The SEAPON project will examine (1) the influence of P dynamics due to climate variability and change on regional ecosystems in the NE, SE and SW United States, (2) the regional ecosystem responses to P dynamics due to land uses and land cover changes, and (3) how climate variability and land use interact to influence P dynamics on regional and continental scales. The focus on P reflects the problem of eutrophication for most of the coastal areas in the region, where excess P from urban and agricultural runoff has dramatically altered the biology of the ecosystem. SEAPON will document the long-term ecological consequences of P dynamics through in situ continuous monitoring, remote sensing and laboratory studies at 29 selected sites located throughout the S.E., N.E. and S.W. United States. The proposed project provides the capacity to monitor and model the effects of large scale climatic changes, regional atmospheric deposition and local land use changes on terrestrial and aquatic ecosystems.
The proposed long term study will enhance the understanding of P dynamics in relation to land use and climate variability and provide a long-term community accessible database that will be used to develop decision and management support tools and predictive models for ecosystem management.