Robert F Stallard


Robert Stallard has worked as a scientist in the National Research Program of Water Mission Area since 1987.He studies how land-cover and climate change affect water movement through soils, weathering, and erosion, and how these, in turn, affect the composition and dispersal of dissolved and solid phases in rivers and trace gases in the atmosphere. Areas of expertise include surface-water hydrology, major element and nutrient biogeochemistry, soil formation and sediment genesis, vegetation-landscape interaction, carbon-cycle characterization on land and in the ocean, and assessment of land-use and climate change. His work has included the study of natural and human-altered landscapes, in the Americas, Southeast Asia, and Africa, including large parts of the Amazon, Orinoco, Mississippi, and Panama Canal Basins and eastern Puerto Rico.

Most of his current efforts are committed to a multi-catchment investigations designed to distinguish the roles of vegetation, climate, and land-cover change and to put this in a hydrologic and biogeochemical framework as well as to examine ecosystem costs and services focusing on water, carbon, and biodiversity. Two projects currently consume most of his time: (1) Work related to the Luquillo USGS Water, Energy, and Biogeochemical Budget (WEBB) Project in eastern Puerto Rico and parallel work in Panama, which has as a goal the comprehensive assessment of catchment hydrology and biogeochemistry in a hydrologically energetic landscapes. In eastern Puerto Rico there is a four-way comparison among watersheds on quartzose and quartz-free igneous rocks, and forested versus agriculturally developed. The parallel work in Panama allows additional comparisons with a forested watershed on a flat landscape developed on quartz-free igneous rocks having thick soils and with a forested watershed on a steep carbonate landscape with thin soils. (2) The Agua Salud Project in the Central Panama Canal Basin examines the manifold effects of different styles of reforestation as compared to mature forested and deforested catchments. He is working on the foundations of a 20-to-40 year study that will be used to assess hydrologic and biogeochemical processes both at a fine scale and at the scale of the Panama Canal Basin.

Five lesser programs are also ongoing: (3) the study of the history of land-cover change in the conterminous United States as it relates to carbon cycling, (4) biogeochemical implications of event-type processes such as floods, fires, and landslides at the hillslope to small-watershed scale, (5) intercomparison of soils, nutrients, and plants in forest-dynamics research plots of the global tropics, (6) biogeochemistry of the Boulder Creek watershed, Colorado, and (7) biogeochemical implications of glacial erosion.


  • National Research Council Post-Doctoral Fellowship: 1981, At the U.S. Geological Survey - Office of Marine Geology, Woods Hole, MA. Clay mineralogy of the Amazon River system.
  • Ph.D., Chemical Oceanography: 1980, Massachusetts Institute of Technology - Woods Hole Oceanographic Institution Joint Program in Oceanography. Ph.D. thesis entitled "Major Element Geochemistry of the Amazon River System."
  • B.S., Earth & Planetary Sciences: 1974, Massachusetts Institute of Technology. Emphasis in Planetary Physics and Chemistry.


  • Research Hydrologist (Geochemist): 10/1987-present. U.S. Geological Survey - Water Resources Division - Central Region - National Research Program. Chief Scientist, Sediment-Water Geochemistry in Large River Systems.
  • Assistant Professor (Geology): 7/1981-9/1987. Princeton University, Department of Geological and Geophysical Sciences.
  • Research Geologist (Geochemist): 12/1979-6/1983. U.S. Geological Survey - Geologic Division - Office of Marine Geology, Woods Hole, MA.


  • American Geophysical Union
  • Association for Tropical Biology
  • Geological Society of America
  • Sigma Xi


  • Woods Hole Fellowship (1974-75).
  • National Science Foundation Graduate Fellowship (1975-78).
  • National Research Council Post-Doctoral Fellowship (1979-80).
  • Princeton University Dusenbury Preceptorship in Geology (1983-87).
  • Research Fellowship at the Smithsonian Tropical Research Institute, Panama (1986).
  • Research Fellowship at the Smithsonian Tropical Research Institute, Panama (1990).
  • Performance Award by US Forest Service for work done in studying mercury contamination caused by gold mining in the Caroní River Basin (1995).         
  • Meritorious Service Award for the Department of the Interior (2002) “In recognition of his exceptional contributions to the development of new and innovative research programs in the U.S. Geological Survey.”