Water, Energy, and Biogeochemical Budgets (WEBB) Program
1U.S. Geological Survey, GSA Center, Suite 400-15, 651 Federal Drive, Guaynabo, Puerto Rico, 00965-5703, USA
2U.S. Geological Survey, 3215 Marine Street, Boulder, CO 80303-1066, USA
The Luquillo mountains of eastern Puerto Rico are the site of U. S. Geological Survey (USGS) research into biogeochemical and geomorphic processes that control the movement and transformation of water, energy, bedrock weathering products, and nutrients in the earth-surface environment. This study was begun in 1990 and is scheduled to last three years, with the possibility of being extended for further data collection. The study area for this research effort includes the 113 square kilometers Luquillo Experimental Forest (LEF) that is administered by the U. S. Forest Service. The LEF has been the site of ongoing research since 1988 as part of the National Science Foundation's Long Term Ecological Research program. In addition, comparative studies are being conducted in the Río Grande de Loíza basin (Loíza basin), an urban and agriculturally developed 600 square kilometers watershed located immediately to the west of the LEF.
The principal elements of the study described in the report are as follows:
Understanding and predicting global environmental change has become a major social and scientific concern of the late 20th century. Scientists from many disciplines and nations around the world have mobilized in this endeavor. During the past three decades, atmospheric scientists have made substantial progress in developing models that account for most of the important components of the climate system. Significant progress is needed, however, in the understanding of the processes associated with the exchanges of water, energy, and carbon between the earth's surface (including vegetation) and the atmosphere. Progress in this latter area requires the knowledge and skills of specialists in fields such as hydrology, biology, geology, and geochemistry, as well as the atmospheric sciences.
To strengthen terrestrial-process research associated with the interactions of water, energy, gases, nutrients, and vegetation, the U.S. Geological Survey (USGS) Global Change Research Program initiated a nationwide program entitled Water, Energy and Biogeochemical Budgets (WEBB). The purpose of WEBB is twofold: to improve understanding of processes controlling terrestrial water, energy and biogeochemical fluxes, process interactions, and process relations to climatic variables; and to improve the capability to predict terrestrial water, energy, and biogeochemical budgets over a range of spatial and temporal scales. This study was begun in 1990 and is scheduled to last three years, with the possibility of being extended for further data collection.
WEBB process studies are being implemented as a systematic program of intensive, long-term field investigations in Colorado, Georgia, Puerto Rico, Vermont and Wisconsin. Study sites were selected on the basis of geographical and environmental diversity. Sites having extant parallel data collection or WEBB-related process investigations were given priority. The sites include such multidisciplinary research locations as the National Science Foundation sponsored Long-Term Ecological Research sites, the U.S. Forest Service Experimental Forests, and the United Nations Educational, Scientific, and Cultural Organization study areas known as International Biosphere Reserves. A major emphasis of WEBB investigations is the development and maintenance of strong collaborative research relationships among scientists in other Federal agencies and the academic community.
Research at the Puerto Rico WEBB site addresses the biogeochemistry of weathering and erosion in the Luquillo mountains. The research will focus on how mass wasting and other hillslope erosive processes control rates of erosion, the composition of solid and dissolved erosion products, and nutrient and carbon dynamics in the soils of the watershed. This research is accomplished by the development of biogeochemical budgets based on regular biweekly and storm sampling, the study of hillslope geomorphic and hydrologic processes, and the study of biogeochemical processes in soils. In addition, the effects of agricultural development on nutrient budgets and gas budgets will be investigated. This research problem involves a comparison between developed and undeveloped watersheds of 1) water, sediment, and nutrient budgets, 2) soil gas fluxes, and 3) gas fluxes from artificial ponds and lakes.