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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).

PulsePod wins third place at the Keller Center’s 10th annual Innovation Forum

Kelly Caylor recently received the third place for the PulsePod at the Keller Center‘s 10th annual Innovation Forum. This event is the opportunity for University researchers to present potentially marketable discoveries. Kelly only had three minutes to convince the judges that the environmental sensing platform will indeed help empowering land managers to make better decisions about their resources. The PulsePod device is combination of hardware and software and provides in-field monitoring of crop health, microclimate, water and nutrients — information that is currently not easily available to farmers.

This year’s forum also included presentations on a new treatment for cancer, a possible solution to widespread water contamination and a type of laser that could diagnose diseases before any symptoms appear. The picture on the left shows this year’s winners (Kelly is in the middle of the second row). You can see the official announcement HERE.

This year was the tenth consecutive Innovation Forum and the Civil and Environmental Engineering Department has a long history of convincing innovators that their ideas are worth commercializing. See the summary of the latest CEE innovations success stories, including the PulsePod, HERE.

AAAS Session on New Earth Observing Methods

 Lyndon Estes and Kelly Caylor recently came back from San Jose, where they attended the AAAS 2015 Annual Meeting to convene a session on “Advances in Earth Observation: Enabling New Insights into Global Environmental Change“, featuring Matt Hansen and Maggi Kelly. The goal of the session was to illustrate how new methods and hardware, such as advanced parallel processing, in-field environmental sensors, and data integration platforms, are starting to fill in the spatial and temporal gaps in our current abilities to observe ecological processes. They had a pretty nice turnout, despite the fact that they were scheduled for 8 am on Sunday morning!

New paper in Science

Kelly Caylor and a group of scientists from Princeton University recently published a paper in Science on the influence of termite mounds in dryland ecosystems. Spotty vegetation patterns in tropical savannas and grasslands can be a warning sign of imminent desertification. However, the group finds that termites can also produce spotty patterns. Their theoretical study, confirmed by field data from Kenya, shows that patterns produced by termite mounds are not harbingers of desertification. Indeed, the presence of termites buffers these ecosystems against climate change.

The paper was chosen as the cover of the edition and was featured in a series of news articles in the US and abroad, including the Independent, Le MondeNature World News, the Japan Times, and the News Reports among others.

If you are interested in the topic, have a look at this other study on the effects of termites on soils published by Elizabeth Pennisi in the same edition of Science.


EcoHydrology Lab at the AGU Fall Meeting



The Caylor Lab will be taking over the AGU Fall Meeting next week. Check out the list of all of our presentations!


Current Members

Kelly CaylorAdam Wolf and Ben SiegfriedB11I-06 – Addressing critical environmental data gaps via low-cost, real-time, cellular-based environmental monitoring, Oral Presentation,  Monday, December 15, 2014, 09:15 AM – 09:30 AM, Moscone West, 2003

Keita DeCarlo, Marcus Spiegel and Kelly CaylorH31D-0646 – Biological Dimensions of Crack Morphology in Dryland Soils, Poster, Wednesday, December 17, 2014, 08:00 AM – 12:20 PM, Moscone West, Poster Hall

Cynthia Gerlein-Safdi, Craig Sinkler and Kelly CaylorH31G-0684 – Modeling Foliar Uptake in Colocasia Esculenta Using High Resolution Maps of Leaf Water Isotopes, Poster,  Wednesday, December 17, 2014, 08:00 AM – 12:20 PM, Moscone West, Poster Hall

Craig Sinkler, Cynthia Gerlein-Safdi and Kelly CaylorPP31D-1177 – Creating High-Resolution Maps of Leaf Water Isotopes Using IM-CRDS and IRMS Techniques, Poster,  Wednesday, December 17, 2014, 08:00 AM – 12:20 PM, Moscone West, Poster Hall

Stephanie Debats, Dee LuoLyndon Estes, Thomas Fuchs and Kelly CaylorB44C-05 – Mapping Agricultural Fields in Sub-Saharan Africa with a Computer Vision Approach, Oral Presentation,  Thursday, December 18, 2014, 05:00 PM – 05:15 PM, Moscone West, 2002

Kelly Caylor, Tom Evans, Lyndon Estes, Justin Sheffield, Beth Plale and Shahzeen Attari, GC53D-06 – Impacts of Agricultural Decision Making and Adaptive Management on Food Security in Africa, Invited Speaker,  Friday, December 19, 2014, 02:55 PM – 03:10 PM, Moscone West, 3005

Hilary Wayland and Kelly CaylorH51E-0661 – Continuous Observations of Leaf Transpiration Isotopic Composition in Two Dryland Species Highlight Sensitivity to Changes in Irradiance and Soil Water Content, Oral Presentation, Friday, December 19, 20140, 4:00 PM – 04:15 PM, Moscone West, 3022



GC11E - The Influence of Changes in Farming Practices, Vegetation, and Land Use on Climate Adaptation, Mitigation, and Ecosystem and Socioeconomic Services I PostersMonday, December 15, 2014, 08:00 AM – 12:20 PM, Moscone West, Poster Hall chaired by Merle Anders , Robert Parkhurst , Kelly Caylor and Lyndon Estes

GC14B – The Influence of Changes in Farming Practices, Vegetation, and Land Use on Climate Adaptation, Mitigation, and Ecosystem and Socioeconomic Services II,  Monday, December 15, 2014, 04:00 PM – 06:00 PM, Moscone West, 3003, chaired K. Kritee, Lyndon Estes, David Lutz and Joe Rudek


Alumni and Collaborators

Catherine Riihimaki, Kelly Caylor and David Wilcove, ED23D-3503 – Planetary boundaries and environmental citizenship: enhancing environmental science through the Princeton University Science and Engineering Education Initiative, Poster, Tuesday, December 16, 2014, 01:40 PM – 06:00 PM, Moscone South, Poster Hall

Salvatore Manfreda, Kelly Caylor and Stephen GoodH33L-02 – An ecohydrological framework to explain shifts in vegetation organization across climatological gradients, Oral Presentation, Wednesday, December 17, 2014, 02:05 PM – 02:20 PM, Moscone West, 3022

Lixin Wang, Stephen Good and Kelly CaylorH51D-0639 – Global Synthesis of Vegetation Control on Evapotranspiration Partition, Poster, Friday, December 19, 2014, 08:00 AM – 12:20 PM, Moscone West, Poster Hall


New paper in Biogeosciences

We recently published a paper in Biogeosciences, in which we generate different rainfall scenarios with fixed total annual rainfall but shifts in (i) frequency vs. intensity, (ii) rainy season length vs. frequency, (iii) intensity vs. rainy season length. These scenarios are fed into SEIB-DGVM to investigate changes in biome distributions and ecosystem productivity. We find a loss of ecosystem productivity with increased rainfall frequency and decreased intensity at very low rainfall regimes (<400 mm year−1) and low frequency (<0.3 event day−1); beyond these very dry regimes, most ecosystems benefit from increased frequency and decreased intensity, except in the wet tropics (>1800 mm year−1) where radiation limitation prevents further productivity gains.