Field Lab — Our Focus

Projects in the Field Lab at the Carnegie Institution of Washington explore ecosystem responses to interacting global changes, controls on the carbon and energy balance of natural ecosystems, and ecology and biogeochemistry at the global scale. These projects include large-scale manipulative experiments, observations on unmanaged systems, and simulation models. Human impacts on the biosphere have become dominant features of the environment, fundamentally altering processes ranging from community structure to the cycles of carbon, nutrients, water, and energy. These impacts present vast challenges for understanding and management, but they also present unusual opportunities for investigations, using the human influences as probes for the mechanisms that underlie ecosystem processes. The research in the Field lab builds on these opportunities, linking studies from the plant to the global scale.

An experimental project on California grasslands explores interacting components of global change. Using technologies that make it possible to alter environmental conditions in largely natural settings, this project involves experimental manipulations of four factors: temperature, atmospheric carbon dioxide, precipitation, and nitrogen deposition. Because the plants in this ecosystem are diverse, small, and short-lived, it is feasible to conduct experiments with a range of environmental changes, over several generations of the dominant organisms. As a consequence, this experiment allows access to two kinds of questions that are likely to be important in all ecosystems but are very difficult to address in most. What new responses emerge when global changes occur in combination? What is the relative importance of responses that do and do not involve changes in community composition? In this experiment, California grassland serves as a model for ecosystem responses to global change. Much of the research in the lab involves extending principles derived from experimental studies to larger scales of space and time. Recently, the group has been interested in the global carbon cycle, including the magnitude, the spatial distribution, and the mechanisms underlying the current terrestrial sink. Combining observations from experimental studies, satellites, and atmospheric monitoring, we are linking top down and bottom up approaches. Approaching the problem from several perspectives and data sets makes it possible to build on the strengths of each kind of observation.

New research in the group addresses other aspects of human actions for the carbon cycle. Past and present land use probably explains much of the current magnitude and distribution of terrestrial sources and sinks. Yet, land use and cover change are characterized only crudely in the current generation of models. Using a combination of satellite data, historical records, and ecosystem modeling, the lab is developing a new, richer perspective on these important processes.

Former members of the research group are on the faculties of Harvard, California Institute of Technology, the Universities of California, Connecticut, Montana, and Northern British Columbia, Michigan State University, California State University, and CNRS (France).

Selected Publications

Contact: Chris Field

    phone: (650) 325 1521 x 213