Research
Soils mantle landscapes all over Earth, and their properties are directly related to local climate, plant and animal activity, geomorphic processes, bedrock and sediment compositions, and the amount of time since the soil started forming.
Paleosols are fossilized soils, trapped in the rock record. Observations of paleosols--from the pedon to micron scale--offer clues to paleoclimate and paleoenvironmental conditions, including rainfall amount, drainage characteristics, landscape evolution, and floral communities.
Trees respond to climate conditions by modifying how they grow. This can involve adjustments to growth rate, photosynthetic rate, and/or water use efficiency.
We analyze stable isotopes of carbon and oxygen in growth rings of living and fossil trees to read signals of past rainfall, temperature, and water sources. This approach provides paleoclimate reconstruction on intra- to inter-annual resolution, a scale much finer than most other proxies.
To reconstruct past climates or environments, we first need robust models that are calibrated in natural systems today.
Using modern data science best practices, we train predictive models between extant substrates (mostly soils or trees) and the climate or environmental variables we are interested in (the response). We then apply these models on paleosols and fossil trees to reconstruct paleoclimates and paleoenvironments.
We acknowledge the invaluable contributions to our research programs by indigenous and local populations and governments. We actively involve local scientists in our research collaborations, train American and Kenyan students in the field, employ local workers, and purchase food and goods from areas near our field sites. We reject colonial-style research programs that extract samples or data from areas at the expense of local populations. We strive to improve the lives of those who welcome us onto their lands.
To learn more about some of the work our colleagues do to improve local communities, please visit: