Title:         Powerful storms, disequilibrium erosion, and fifteen
		years of watershed studies in eastern Puerto Rico

			Abstract

 The U.S. Geological Survey (USGS) Water, Energy, and Biogeochemical
Budgets (WEBB) Project in eastern Puerto Rico is a landscape-scale studies  based in the humid tropics where the intense storms, warm temperatures, moist conditions, and luxuriant vegetation promote especially rapid hydrological, biological and chemical processes - photosynthesis, respiration, decay, chemical weathering, and physical erosion. The WEBB Program involves a double pair-wise comparison of humid-tropical montane streams on granitic bedrock and fine-grained volcaniclastic bedrock. For each bedrock type, one catchment is covered with mature rainforest, and  the other catchment is affected by grazing, cropping, and minor  urbanization.  Biogeochemical budgets are being monitored, and include water, major dissolved constituents, nutrients, carbon, and sediment.
The WEBB Project has successfully synthesized its first fifteen
years of data, and has addressed the influence of land cover, geologic,
topographic, and hydrologic variability, including huge storms on a wide range of hydrologic, physical, and biogeochemical processes. Examination of landscape-scale processes in a changing world requires the development of detailed landscape-scale data sets, including a formulation of reference states that can act as surrogate experimental controls. For example, the concept of a landscape steady state or equilibrium provides a convenient reference in which present-day observations can be interpreted. Extreme hydrological states must also be described, and WEBB has  successfully examined the role of droughts and large storms and their impact on geomorphology, biogeochemistry, and biology.