We study how ecosystems and the services they provide to people are changing at regional levels. Our group consists of ecologists, remote sensing specialists, biogeochemists and land-surface modelers, working together scientifically to support conservation, management, and policy development.

The Caldeira Lab conducts research to try to improve the science base needed to allow human civilization to develop while protecting our environmental endowment.

I am interested in how microbial life affects the chemistry and climate of our planet today and throughout time.  I study the activity of bacteria and archaea driving carbon, nitrogen, and sulfur cycling in diverse modern ecosystems, with a focus on processes directly or indirectly involved in greenhouse gas cycling.  I am especially interested in exploring the activity and metabolic capabilities of uncultured bacteria and archaea on the single-cell level, and relating activity on the micron scale to chemical cycling on the global scale. I use a combination of techniques from molecular biology and isotope geochemistry, including stable isotope probing, fluorescence in situ hybridization (FISH), Nanoscale Secondary Ion Mass Spectrometry (NanoSIMS), Isotope Ratio Mass Spectrometry (IRMS), and DNA and RNA analysis.

My group specializes in high resolution studies of climatic and oceanic variability during modern times as well as over the past 50 to 12,000 years. Our most productive archives for this work include the skeletons of long-lived corals from the tropics and the deep sea, as well as sediments from lakes and marine environments. We use chemical, isotopic, and morphological measurements of these materials to investigate the timing and rates of change associated with past solar and C cycle excursions. Current field areas include the Galápagos Islands, Antarctica, the Line Islands, Kenya, Easter Island, Chile, Patagonian Argentina, Tierra del Fuego, and Palau. We are also well into a multi-year effort to collect deep sea corals to better understand their ecology as well as their self-contained records of change in the deep sea. We do this work using deep diving research submersibles in the Gulf of Alaska and the central tropical and north Pacific.

The Field Lab focuses on basic ecological research from the ecosystem scale to the global scale. Emphases include climate-change impacts, ecosystem responses to multi-factor global changes, the terrestrial carbon cycle, biosphere/atmosphere interactions, and biogeochemical consequences of changes in species composition. We use experiments, models, and satellite data for a synthetic perspective.

Our research interests span a range of topics including the scientific basis for water resources management, hydroecology / ecohydrology, surface - groundwater interactions, groundwater allocation policy, fluid flow and solute transport processes, innovative simulation techniques, and cutting-edge technologies in hydrogeophysics and remote sensing in hydrology.

My research is focused on understanding the coupling of the carbon and water cycles at the land surface, to allow predictions of ecosystem response to a changing climate.  I am especially  interested in how water (and energy) availability and vegetation function respond to each other across timescales and how vegetation water content influences this behavior. To address these issues, I primarily use the tools of remote sensing data analysis (especially at microwave-frequency) and model development. A necessary step in doing so is the development of new remote sensing datasets and the development of statistical methods to best evaluate and combine different imperfect datasets.

Our group studies biogeochemical and ecological processes in forest and agricultural systems. In particular, much of our research focuses on the effects of land use change and other human caused changes on biogeochemical processes and trace gas exchanges in tropical ecosystems. In the past, most of our work was at the interface between terrestrial ecology, soil science and atmospheric science. For example, we used our knowledge of variations in soils and forest ecosystem processes to develop an ecologically based global budget for the greenhouse gas nitrous oxide, and we carried out research showing how land use change and agricultural intensification in the tropics contributes to the increasing atmospheric concentration of trace gases.

This research group focuses on the environmental and equity dimensions of intensive food production. They have been involved in a number of field-level research projects throughout the world concerning issues of aquaculture and livestock production, high-input agricultural development, biotechnology, climate-induced yield variability, and food security.

The Vitousek Group and colleagues carry out research related to nutrient cycling, most notably nitrogen and phosphorus, throughout the range of environments and ecosystems. The Hawaiian Islands are the focus of the majority of studies. Our group has looked at nutrient dynamics in the soil profile, litter, native forest ecosystems, forest and grassland systems affected by invasive species and agricultural systems. Studies have documented how an invasive grass has changed the fire frequency and suppressed the ability of the native forest to return. How an invasive nitrogen fixing tree changes the nutrient dynamics in the soil and facilitates further encroachment by other non-native plants.