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Welcome to the Princeton Ecohydrology Lab Website!

We've recently moved into a new site, so please let us know if you have any comments or - more likely - find any missing or dead links.

  • Dryland Ecohydrology

    Life in dryland savanna ecosystems is reliant on the spatial and temporal distribution of rainfall. In order to understand the impacts of changes in rainfall on woody vegetation patterns, our group has developed a set of modeling approaches that combine existing stochastic soil water balance models with a resource trade-off hypothesis pertaining to the organization of dryland vegetation communities. This framework has provided a mathematically tractable optimization problem which we have applied to southern African savannas, the Rio Salado basin in the US southwest, and a central Kenyan ecosystem.

  • Isotope Hydrology

    Understanding the coupled interactions between hydrology and ecology requires new measurements of environmental process at the landscape level. To this end we are beginning to use stable isotopes of hydrogen and oxygen as a tool for partitioning land surface water vapor fluxes into evaporation and transpiration components. We have recently constructed a new eddy flux tower in Likipia, Kenya which will be outfitted with a laser-based isotope analyzer from Los Gatos Research. This instrument allows continuous δ18O and δ2H measurements (1 Hz) in water vapor. It has great potential to answer both theoretical (e.g., kinetic fractionations in soil evaporation) and practical questions (e.g., the effect of vegetation structure on evaporation/transpiration partition).

PulseLab in California and New Mexico

As part of the PulseLab project, Adam Wolf, Lyndon EstesBen Siegfried and Matteo Kruijssen (PEI Grand Challenge intern working with Lyndon for the summer) went out in California in June to install sensors in agricultural fields with the goal of realtime monitoring of crop growth and microclimate in control, water limited, and N-limited corn fields. Since crop growth forecasts are largely driven by remote sensing, these observations help to improve space-borne satellite retrievals for modeling, but also provide important constraints to the local microclimate, including temperature and soil moisture, which are critical to improving the predictions of climate change impacts on crop productivity. Check out the pictures of their fieldtrip below!

End of July, Adam and Ben went out again, to New Mexico this time. You can see the pictures of the pods installation HERE.

Two New Grants Awarded

We are very happy to have been awarded new grants from both NSF and NASA!

The NSF grant falls under the Water, Sustainability, and Climate program, which selected our proposal to study the “Impacts of Agricultural Decision Making and Adaptive Management on Food Security in Africa”. Focusing on Kenya and Zambia, this project will investigate how near-term hydrological and agro-ecological forecasts can be used to improve intra-seasonal water and farm management decisions, and thereby improve livelihood security. This is a 5 year grant led by Kelly and Justin Sheffield at Princeton and Tom Evans, Shahzeen Attari, and Beth Plale at Indiana University, in collaboration with Moses Mwale of the Zambia Agricultural Research Institute, Professor Jesse Njoka of the University of Nairobi, and Dr. Luke Olang of the IGAD Climate Predictions and Applications Centre. Adam and Lyndon will also be closely involved with this research: Adam will develop the real-time environmental sensor network that will form a key part of the methods, while Lyndon will develop the agro-ecological forecasting methods.

The NASA grant was awarded to Lyndon under the New Investigator Program in Earth Science for his proposal entitled “Integrating crowdsourcing, in situ sensing, and spaceborne observation to understand the sustainability of smallholder agriculture in African wet savannas”. This project will use a combination of remote sensing, field observations by PULSE lab sensors, machine learning (led by Stephanie Debats), and crowdsourcing to detect trends in the area and productivity of Zambian maize farms since 2000. The aim is to assess 1) whether yield increases are correlated with cropland expansion or contraction, 2) whether yield increases precede cropland changes, and 3) whether yield gains correspond to increased climate sensitivity. This research will provide insight into the socioeconomic and ecological sustainability of agricultural expansion in a region of increasing climatic variability and rapid growth.

Field Ecohydrology at Mpala

Kelly’s Field Ecohydrology class at the Mpala Research Center was recently highlighted on the National Science Foundation website. The class is part of the Tropical Biology in Kenya semester organized by the department of Ecology and Evolutionary Biology at Princeton University. Kelly’s class is focusing on the feedback between hydrological processes and human activities and ensures that students develop practical skills and familiarity with interactions between humans and the environment.

Mpala Live! website launched

The Mpala Research Center just launched Mpala Live!, an interactive website featuring a round-the-clock view of the hippos, elephants, and other incredible species that frequent Hippo Pools. It allows vistors to experience Mpala with scientists as they study relationships among humans, animals, and ecosystems and to learn about the wildlife of Laikipia with a field guide featuring a wide range of species from aardvarks to zebras. In addition, the Mpala Live! classroom introduces teachers and students and parents and children to a unique curricula keyed to Mpala’s flora and fauna. Make sure to check it out!