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I am Tongbi Tu, a new postdoc in the lab.  I am working on a SESYNC Pursuit to study causal pathways and feedbacks within complex water management systems. This project integrates ecology, hydrology, and water law. The interdisciplinary team is composed of Sankar Arumugam (NCSU), Xiaoli Dong (UC Davis), Caitlin Dyckman (Clemson Univ.), Ted Grantham (UC Berkeley), Lars Olson (Univ. of Maryland), Benjamin Ruddell (Northern Arizona Univ.), Nicola Ulibarri (UC Irvine), and Albert Ruhi (UC Berkeley).

In this working group we will apply physically-based and time-series models to investigate how reservoirs can help provide engineered resilience to socio-environmental systems–especially during periods of drought. We will use a variety of approaches to detect direct and indirect causal pathways and feedbacks between hydrologic conditions, human uses, and downstream ecological outcomes in the Lower Colorado River basin. A better understanding of the complex dynamics of water systems can help advance sustainable freshwater management–a critical need in the face of increasing competition for scarce freshwater resources.

Hi there! My name is Guillermo de Mendoza and I am a postdoctoral researcher in the lab. Together with David Herbst (UC Santa Cruz) we are studying how stream invertebrate communities are changing over time and across the state of California. We are using a dataset collected via the Surface Water Ambient Monitoring Program (SWAMP). Our question concerns patterns of distance-decay of similarity–that is, dissimilarity in invertebrate communities across spatial and environmental distances.

DDS relationships are typically controlled by environmental gradients, dispersal barriers, and ecological drift. Here we are asking whether DDS can vary over time as well–in response to fluctuating hydrologic conditions. This research will show how drought influences spatial patterns of stream invertebrates (‘who is where’), and will help us further understand how freshwater biodiversity may respond to the multi-year droughts that characterize California’s hydroclimate.

Check out our new paper, published in a Special Issue in California Agriculture that explores how research informs policy-making

Our latest post in CaliforniaWaterBlog describes how environmental outcomes can be improved when water is allocated using a functional flow approach. Read more here!

Understanding how freshwater ecosystems respond to environmental change requires knowing whether recent changes are within the bounds of natural variation or if these systems are, instead, entering new states.

I am Xavier Benito-Granell, an aquatic ecologist and new SESYNC Postdoc Fellow working on questions that revolve around the long-term resilience of diatom communities and their ability to capture regime shifts in lakes. My project, co-developed with my external mentor Albert Ruhi, aims at identifying abrupt transitions in palaeoenvironmental records of high-elevation Andean lakes.

We are applying time-series methods on a unique combination of diatom community data, biophysical data (pollen and sediment geochemistry), and human data (archaeological records). This historical perspective combines data at decadal to millennial scales, and allows asking whether early-warning signals precede regime shifts–something that would be useful to try identify lakes that may be on the verge of a critical transition. We hope this work will advance our understanding of the long-term dynamics and trajectories of high-altitude lakes, and of their responses to ongoing anthropogenic and environmental change.

Paramo landscape around Lake Patoquinuas, Cajas National Park (Ecuador)

The past two weeks have been rather busy. First, we hosted Chris Trisos, Postdoc Fellow at SESYNC, to continue working on a paper on Modern Portfolio Theory applied to conservation science.

We then welcomed Jordi-Rene Mor, visiting graduate student from the Catalan Institute for Water Research (ICRA) and the University of Barcelona.  Jordi will be joining us for 4 months, to work on stable isotope data from a number of Catalan Mediterranean rivers affected by drought and wastewater effluents. Welcome, Jordi!

Last but not least, we discussed novel flow regimes and submitted a grant proposal to the California Sea Grant (Special Focus Awards). If we get funding we will be doing some exciting food-web research in reference and restored wetlands at the South Bay Salt Pond Restoration Project.

More soon!

Maria Sanchez-Montoya is joining us for three months. She is visiting from the University of Murcia (Spain) and will develop a project on the animal community responses to river drying. Welcome, Maria!

We are very excited to announce that Lise Comte started her postdoc position at the Ruhi Lab. She will be working on two projects on (i) temporal responses of riverine fish communities to flow and temperature anomalies at the global scale, and (ii) the alteration-invasion nexus in the U.S. More soon. Welcome, Lise!

The Ruhi lab is taking off @ 319 Wellman Hall. Stay tuned for updates!