Carol Baird Graduate Student Award for Field Research

The UC Berkeley Natural History Field Stations have announced a new award for graduate students conducting field research in or around the following Berkeley field stations: the Angelo Coast Range Reserve, Blue Oak Ranch Reserve, Hastings Natural History Reservation, Point Reyes Field Station, and Sagehen Creek Field Station. Proposals are due September 30th, 2017 and should be sent to For more details on the award and proposals, click here (link leads to the Baird Award announcement on the UC Berkeley Field Stations website.)




Research at Angelo- Dr. Sarah Kupferberg

Dr. Sarah Kupferberg’s research is focused on food web ecology, amphibian population biology, and conservation of aquatic ecosystems in California. A particular interest of Dr. Kupferberg is the effects of dams and diversions on the physical and biotic conditions for wildlife. To investigate these issues, she conducts field research and experiments in rivers with hydroelectric projects, drinking water reservoirs, and flood control projects. Dr. Kupferberg is also applying her extensive knowledge of aquatic ecosystems at the policy level, reviewing stream restoration plans and working with engineers to facilitate designs that are compatible with hydraulic and biological needs.

Angelinos and Eel River Recovery Project volunteers have worked together with Dr. Kupferberg to count (and rescue!) egg masses of Foothill Yellow-legged Frogs (Rana boylii).  R. boylii lay their eggs at traditional oviposition sites in the river every spring.  The size of tennis to soft balls, these black-speckled jelly masses are more conspicuous than the adult frogs. What do you notice first in the photo below?

Conveniently for biologists interested in conserving this species (which is currently under review for protection by the Federal and California Endangered Species Act), adult females lay one clutch of eggs each spring. So one egg mass = one breeding female frog.  A census of clutches thus provides an index of the total size of the breeding population. Repeating the counts annually can indicate if populations are growing or declining. In the case of the Angelo Reserve, the population has fluctuated over the last 25 years, but remains basically stable. In contrast, since 2012 we have been observing a growing population along the banks of the South Fork Eel- this is where the California State Parks stopped operating the Benbow Dam in 2016 to impound the river and create a summer lake.  In the Spring of 2016 in advance of the de-construction of the Benbow Dam, ERRP volunteers ( and Angelinos relocated 100’s of egg masses (10,000’s of thousands of tadpoles!) out of harm’s way. Now that the high flows from winter 2017 have reconfigured the gravel bars at the restored dam site, we will monitor how the frogs respond.

The Willits Hub Fish & Aquatics Restoration Day

Sarah Kupferberg, Bill Dietrich, and Mary Power participated in a Fish and Aquatics Day celebration as a kickoff of the “Willits Hub” on Sunday, March 19th 2017.   The Willits Hub is being launched as a meeting place and headquarters for several non-profit environmental groups in the Willits area, including the Eel River Recovery Project.

Pat Higgins (ERRP’s Managing Director) invited Sarah to give a talk on her 20+ years of research on Rana boylii, i.e. the Foothill Yellow-legged Frog, a native frog that breeds in the Eel River.  Bill talked about the Critical Zone (the thin, water-exchanging skin of the Earth between the top of the vegetation and the bottom of the weathered bedrock beneath the soil) and why the geology of this zone matters for water storage and resilience to drought in the forests and grasslands along the California North Coast.  Mary told a bit about the history of the Angelo Reserve—the stories of the Angelo-Steel families who protected this land, and some of the adventures that students and scientists have had in studying its creatures, plants, soils, river food webs, and landscapes. In addition, Pat gave brief talks about sediments and river bugs, and Park Steiner reported on his very long-term studies of chinook carcass trends in the upper mainstem Eel and Tomki Creek.  A meeting highlight was the remarkable footage shown by filmmaker Shane Anderson as a preview of his forthcoming movie about the Eel: “A River’s Last Chance”.

We felt fortunate to meet old friends and new ones at the Willits Hub who share our concern over the future of the Eel River ecosystem, and look forward to future get-togethers, some at the Angelo Reserve!

Credit to Pat Higgins for the photo collage.

Mary Power and Gabe Rossi, and the stalwart student teams doing Eyes on the Eel surveys: The Movie.

Here’s a link to the movie (released in mid May 2017) on our Eyes on the Eel surveys.

Shot by Amy Miller and Josh Rosen, Spine Productions, the movie features Gabe Rossi, myself, and many of the stalwart students that do this survey at 8 river reaches along the S. Fk Eel and mainstem Eel.  The film was funded by Howard Hughes Medical Institute, which has realized that the Milieu Exterieur affects the Milieu Interieur.

It was a huge pleasure to work with Josh and Amy, who also have filmed canopy research by the Dawson Lab, and a movie on Hydrowatch featuring Inez Fung, Todd Dawson, and Bill Dietrich explaining their life cycle of water work in the intensively monitored Rivendell basin draining to Elder Creek.


Left to Right: Gabe Rossi, Keith Bouma-Gregson, Victoria Uva, Nick Lapaglia, Robbie Gould at the mainstem Eel River, Summer 2016

Listening to the forest breathe: monitoring tree trunk sap flow and size

Water is a polar molecule, a property that accounts for many of its unique physical properties

Water is a polar molecule, a property that accounts for many of its unique physical properties. Photo credit: Jesse Hahm

Trees must pull water from soil and rock, where it is held at tension, to their leaves, where it evaporates to the atmosphere through open stomata. This process, called transpiration, is a major component of the hillslope water budget and can dramatically affect the local climate by lowering air temperature and increasing water vapor concentrations. Understanding how trees use water is a major topic of research at the Angelo Coast Range Reserve. How does the seasonality of transpiration differ between species? At what water content (and potential, or tension) in the subsurface do trees become so stressed that they close their stomata to prevent embolisms (damage to their vascular tissues)? How does rock type influence how hard trees must pull to extract water from the vadose (unsaturated) zone? How do trees access water to continue to transpire throughout the summer drought in Mediterranean climates?

When does this Douglas Fir become water-stressed?

When does this Douglas Fir become water-stressed? Photo credit: Jesse Hahm

To answer these questions, researchers are monitoring tree physiological response to environmental conditions in the Angelo Coast Range Reserve. Sapflow (the vertical ascent of water through xylem) can be measured using a simple sensor consisting of three prongs placed into the sapwood of the tree. The central prong emits a heat pulse, and the two surrounding prongs sense changes in temperature. Flowing sap advects the heat pulse so that a temperature rise is sensed sooner in the upper temperature probe. This principle enables the sapflow velocity to be determined.

Bark must be scraped away to place sensors into the sapwood. The fleshy red bark is characteristic of tan oaks.

Bark must be scraped away to place sensors into the sapwood. This fleshy red bark is characteristic of tan oaks. Photo credit: Jesse Hahm

Sapflow sensors have three metal prongs aligned parallel to the flow of sap. The central prong emits a heat pulse every half hour.

Sapflow sensors have three metal prongs aligned parallel to the flow of sap. The central prong emits a heat pulse every half hour. Photo credit: Jesse Hahm

As the tree ‘pulls’ water up from below, tension increases in the water column in the xylem. This suction can influence the size of the tree trunk, which can be measured with very precise piston dendrometers. These sensors capture the diurnal size variation due to changes in both water content and potential as well as tree growth.

This piston dendrometer senses changes in trunk radius with micrometer-scale precision.

This piston dendrometer senses changes in trunk radius with micrometer-scale precision. Threaded bolts are sunk into the heartwood of the tree to provide a stable reference frame. Photo credit: Jesse Hahm

Eyes on the Eel!


Some evening in June, July, or September, you may see a wet, tired crew of river ecologists eating burgers at The Peg Inn (Never don’t stop there!) or the Chimney Tree House in southern Humboldt.  Or you may see our EoE tags along the river–The “Eyes on the Eel” is an ongoing survey of the state of river and tributary ecosystems along Eel mainstems and tributaries, one of four long term research tasks outlined for the Eel River Critical Zone Observatory.  Led by Profs Stephanie Carlson and Mary Power, and graduate students Suzanne Kelson, Gabe Rossi, Phil Georgakakos, and Keith Bouma-Gregson, our Berkeley-based student crews have been, frankly, amazing at putting up with long days, hard work, wet clothes, while steadfastly documenting physical conditions, cyanobacterial and algal abundances, invertebrates, and vertebrates along 48 transects and 16 pool-riffle units in four tributaries and four mainstem sites down the South Fork and mainstem Eel River.  We thank these student researchers, and to the  generous land owners who have given us permission to visit their property for one day per month for our surveys.  We will be working to publicize our observations in ways that will be widely accessible and informative, and, we hope, will invite collaboration and comparisons with observations of others along the Eel.  For example, Eyes on the Eel, in some ways, complements the extensive snorkeling surveys of deep pool habitats performed by the Eel River Recovery Project.  The rationale and methods for this effort are described in more detail under the Research section.

September 2015 Eyes on the Eel Crew in Wilderness Lodge meadow

Angelo and Eel River CZO on local radio

We were very pleased and grateful for an audio report from Berkeley undergrad Sohil story about his experience at the Angelo this summer.  His grad student mentor Suzanne Kelson reports “His story was chosen by the local radio station (KOZT the coast, “I love this town”) and played Thursday, August 13. Very cool! I’m proud of Sohil”
Here’s the link to listen to the story:

Keith Bouma Gregson and Mary Power have both chatted about cyanobacteria, drought, and other river issues with Patrick Higgins, Executive Director of the Eel River Recovery Project, on KMUD’s Monday Morning Magazine., e.g.,  June 1 2015.

Jerry Schubel, Director of the Aquarium of the Pacific in Long Beach California, hosts Coastal Conversations, a monthly program that deals with major issues confronting the nation’s coastal areas—marine and in the Great Lakes.  He was the lead author of a July 2014 of the National Academy of Science National Research Council entitled “Enhancing the Value and Sustainability of Field Stations and Marine Laboratories in the 21st Century”.  On Feb 27, Jerry invited three authors of that report, Felicia Coleman from Florida State University’s Coastal and Marine Laboratory, Rob Plowes, from the University of Texas, Brackenridge Field Laboratory, Mary Power, from the University of California, Berkeley, Angelo Coast Range Reserve, and Peter Kareiva from The Nature Conservancy, to discuss the importance of natural history field stations for research, education, and outreach, and ways of increasing their impact and viability  into the 21st century. 

Climate extremes and the Critical Zone

As people who had planned to live ordinary lives face early-onset climate change, we are discovering that it not the change in average temperature or precipitation, but the extremes that will change our future. In the US alone, we are already seeing parched landscapes throughout western North America, while deluges and storm surges destroy crops and infrastructure throughout the Midwest and the East coast. Droughts and heat shocks, or deluge and super-storms, are following atmospheric and ocean warming, because, as Gregory Johnson’s haiku version of the IPCC 2014 report states,

“Wet will get wetter/and dry drier, since warm air/ carries more water.”(

By now, we have little ability to correct the atmospheric and ocean conditions that have triggered weird, often violent weather around the globe (although we should rapidly change our energy sources to avoid making it worse).   Instead, we must turn our attention to the skin of the Earth, where life meets rock, and cycling water is received, stored, transformed, and released back to the atmosphere, or as runoff to surface waters. We call this Earth skin the Critical Zone. It extends from the top of the vegetation to weathered bedrock deep beneath our feet. The lower part of the Critical Zone is largely unobserved, but of crucial importance. It begins where fractures in bedrock give plants and microbes access to stored water, and provide flow paths feeding the springs, rivers, wetlands, lakes, and estuaries on which most terrestrial life depends. Careful stewardship of Critical Zones—the vegetation and the soil and bedrock beneathe–could help us buffer, and even ameliorate, temperature and precipitation extremes at local, regional, and, perhaps some day, global scales. But to steward something, anything, it must be understood. That is the purpose of the network of Critical Zone Observatories, funded by the US National Science Foundation.

See the Research section of this web site for reports from studies at the Eel River Critical Zone that 1) explain how uplift and drainage affect the ability of bedrock underlying Coast Range hillslopes to store and slowly release the water that keeps springs, streams and rivers flowing during drought (Rempe and Dietrich 2014); and 2) predict that temperatures in our wooded landscapes would be elevated 1-2oC if we replaced all the broad-leafed trees with conifers (Link et al. in preparation).