Improving predictions of food security in subsistence dryland agriculture
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.
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.
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).
A new class on science, society and food was launched this semester. The class, officially titled “Science, Society & Dinner”, is taught by Kelly Caylor, in collaboration with Chef Craig Shelton, and with assistance from Rozalie Czesana ’18 and Chef Michelle Fuerst.
A few pictures of the first class are available below. In that class, students learned about challenges of food security, production consumption and waste in the US, China, India and Brazil. They also practiced knife skills and tasted fresh-baked baguettes with Beurre d’Isigny from Bon Appetit and sampled five varieties of salt from the Savory Spice Shop in Princeton. They also sampled a non-alcoholic wine before and after lemon, sugar, black pepper and bleu cheese to note effects on perceived flavor.
A takeaway: Understand ingredients to use them well and wisely – reducing waste in the process.
In a good community connection, this new freshman seminar is being taught at the John Witherspoon Middle School Teaching Kitchens.
Andreas Colliander, Thomas Jackson, Steven Chan, Narendra Das, Seungbum Kim, R. Scott Dunbar, Rajat Bindlish, Lan Dang, Aaron Berg, Tracy Rowlandson, Kelly Caylor, Michael Cosh, Hala AlJassar, Ernesto Lopez-baeza, Jose Martínez-Fernández, Angel Gonzales-Zamora, Heather McNairn, Anna Pacheco, Mahta Moghaddam, Carsten Montzka, Claudia Notarnicola, Georg Niedrist, Thierry Pellarin, Jouni Pulliainen, Kimmo Rautiainen, Judith Ramos, Mark Seyfried, Zhongbo Su, Yijian Zeng, Rogier Van der Velde, Marouane Temimi, Marc Thibeault, Wouter Dorigo, Mariette Vreugdenhil, Jeffrey Walker, Xiaoling Wu, Todd Caldwell, Michael Spencer, Peggy O’Neill, Dara Entekhabi, Simon Yueh, and Eni Njoku, H43H-1626 – SMAP L2/L3 Soil Moisture Product Validation using In Situ Based Core Validation Sites, Poster, Thursday, 17 December 2015, 01:40 PM – 06:00 PM, Moscone South, Poster Hall
This summer Drew Gower traveled to Kenya for a three-week mission wrapping up one project and launching another. From 2012 to 2014, researchers from the Caylor Lab and the Ostrom Workshop at Indiana University collected water use and agricultural production data in 25 community water projects (CWP) across the Laikipia region as part of a Coupled Natural and Human Systems Grant from NSF. The researchers then used this data to create individualized reports describing current practices in each project and comparisons with those of their neighbors. During the first week of his trip, Drew met with the management committees of ten CWP clustered around the Ngare Nything and Timau rivers to deliver the last of these reports and to discuss their content with interested members.
After successfully closing out the project described above, members of the Ecohydrology Lab look forward to continuing its work in Laikipia through a new project funded by a Water Sustainability and Climate grant from the NSF. This project will use environmental data collected through a field-based sensor network, along with the results of farmer surveys, to better understand how smallholders respond to climate shocks and to predict when crop failures may be imminent. Drew spent the last two weeks of his trip working with the lab staff to assemble, program and deploy these sensors at sites around the Nanyuki and Likii Rivers. Since Drew’s departure, the lab staff has deployed additional sensors at sites near the Ngusishi River as well.
Students from the Turkana Basin Institute Field School recently spent some time at Mpala, learning about the field ecology of African savanna. John Gitonga, helped by other members of the EcoHydrology Lab at Mpala, gave the students a short course on dryland hydrology. The group also went to visit our flux tower and got a full tour of the different instruments.