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).

Turbidites and rip-up clasts in Elder Creek

Elder Creek, part of the South Fork Eel River watershed, lies in the Franciscan Formation found underfoot in most of the Northern Coast Ranges of California. The rocks here were deposited in marine environments when the Farallon slab was still subducting under the North American plate at this latitude. Subsequent uplift following the passage of the Mendocino Triple Junction has elevated these rocks out of the sea.

Clastic sedimentary rocks found in Elder Creek record information about their depositional setting. Grain size, lithology, and shape all provide clues about the energy of the flow and the time spent in transit, sorting and abrading. The vast majority of the rocks in Elder Creek are turbidites, formed from turbidity currents: dense slurries of sediment sloughing off the edge of the continent, rushing off the continental slope to final resting places in deeper, still waters. These currents are thought to be triggered by earthquakes, among other things.

Turbidites contain sand and pebbles that were rounded in terrestrial rivers prior to their arrival at the ocean. They also contain small clay-sized particles that fall out of the ocean water column (the long snowfall, in Rachel Carson’s words). As numerous currents are laid down over time, they create a rhythmic sequence of grain sizes, with a fining upward sequence recording stratigraphic ‘up’ (left to right in the image from the bed of Elder Creek below.)


Rhythmically bedded turbidite sequence (pebble to sand to clay size), Elder Creek. Photo credit: Jesse Hahm

Sometimes turbidity currents race over clay-sized mud deposits (shale). They pick up bits of the semi-lithified shale and carry them along. These shale bits are called rip-up clasts or intra-formational clasts. They are recognized by their darker color and angular shape, and are often much larger than the terrigenous sediment that surrounds them.

Rip-up (intra-formational) shale clasts in sandy matrix, Elder Creek

Rip-up (intra-formational) shale clasts in sandy matrix, Elder Creek. Photo credit: Jesse Hahm

Measuring stream discharge with the salt dilution technique

Measuring water fluxes in the Eel River Watershed is extremely important. We are in the midst of a multi-year drought and demands on the water supply for agriculture and rural use are only increasing.

An ongoing project at the Eel River Critical Zone Observatory is to improve existing stage-discharge relationships, to better document the amount of water flowing through the watershed. Stage refers to the height of water in the river, and discharge refers to the volume of water that flows by in a given time.

We can measure the stage with an automated system that makes use of pressure transducers, but knowing the discharge is complicated because of the ever-changing geometry of the river bed and the turbulent nature of flowing water. The approach to this problem is to develop an empirical relationship between stage and discharge across a range of stages, from low summer baseflow to high winter floods.


Salt dilution technique by David Dralle

Salt dilution technique by David Dralle

Here David Dralle is demonstrating the salt dilution technique to measure discharge on the South Fork of the Eel River, just downstream from Headquarters. A known volume of salt solution is added to a turbulent stretch of the river, and the increase in electrical conductivity is measured downstream, after the salt is well mixed into the flow. The more the salt is diluted, the higher the flow.

Dan Moore has written a very helpful series of articles on the use of the technique. For more information, see the intro to the series, published in Streamline Water Management Bulletin (

Phil G encounters invaders in Hunter’s Pool, just downstream from Angelo


Invasive red swamp crayfish.  Photo by Phil Georgakakos.

Phil Georgakakos sent these photos yesterday of two invaders–the red swamp crayfish, Procambarus clarkii, and bullheads tentatively identified by Mary Power as black bullheads, Ictalurus melas.  (It may be a brown bullhead, check out the pectoral spine-if smooth, black, if barbed, brown bullhead, I. nebulosus).  Phil and I had seen red swamp crayfish in S.Fk. Eel just below its confluence with Ten Mile Creek near Laytonville last March (see previous post), and Sarah Kupferberg and I have found them upstream within the reserve later, but all the individuals we saw were dead.  Phil yesterday found the first live specimen–a male (see the claspers where its belly button would be, were it a placental mammal…).


Baby Bullhead. Photo by Phil Georgakakos


Photo by Phil Georgakakos

While we are concerned about these invaders harming native species in the Eel, I have to mention how cool bullheads are.  These catfish know each other individually through chemical recognition–fish respond very differently when “enemy” vs “friend” water is poured into their aquarium (google John Todd’s article in Scientific American).


Bullhead family. Photo by Phil Georgakakos.

Mother and Dad take care of the fry (the little black guys with adorable mustaches in Phil’s photo, above.), marching them around pool bottoms in little swarms as they learn to feed.   But what are they feeding on?  Bill Dietrich was just wondering if they, among other reasons, may be why we no longer see little native freshwater mussels, and are so worried about their failure to recruit in rivers along the North Coast…bullheads suck up their food from the substrate, and this might include newly settled mussels in depositional pool habitats…

Eel River Algal Foray 2015

On June 12-14, 2015, the Angelo Reserve was the site of another wonderful Eel River Algal Foray. Algal experts Dr. Paula Furey and Professors Rex Lowe and Yvonne Vadeboncoeur came out from Minnesota, Wisconsin, and Ohio to teach our neighbors and students from the Eel, Klamath, and other North Coast watersheds how to identify the major taxa of algae in the Eel River and other rivers of the California North Coast. Paula did postdoctoral algal field research in the Eel at Angelo. Rex (her Ph.D. advisor and also a long-time Angelino), Paula, and another of Rex’s former students, Jane Marks, have taught Berkeley ecologists much of what we know about Eel River algae, which play important roles in river and coastal food webs.   Rex Lowe has inspired students of algae throughout the US during his many forays and longer-term classes.   For a number of years, he and Paula have led Algal Forays at the Angelo Reserve–two-day events in which we invite our Eel and Klamath River neighbors to come learn about algae by collecting it, then identifying it (with Paula and Rex’s guidance) under microscopes in the Angelo Environmental Science Center.

Algal Foray 2015 group-sml

2015 algal participants from top left to bottom right: Wes Cooperman, Lindsey Bouma-Gregson, Susan Fadness, Wendy Gregson, Paul Domanchuk, David Sopjes, Robin Richardson-Coy, Darren Mireau, Eli Asarian, Diane Higgins, Koiya Tuttle, Pat Higgins, Nathan Rich, Jacob Pounds, Matt Hanington, Ari Nuri, Elliott Gaines, (lower left:) Shelly Pneh, Gabe Rossi, Rex Lowe, Rich Fadness, Paula Furey, Keith Bouma-Gregson, Mary Power, Yvonne Vadeboncoeur, Evan Deas, Shirene Misif, Sharon Edell, Eden Edell, Mike Deas. Photo by Brian Gregson.

“The Good, the Bad, and the (other) Algae”.

Foray Class 2015 sml

Rex Lowe (red T shirt right) and Nathan Rich (red T shirt left) and Foray Folk gazing at algae at 400x during the 2015 Foray. Photo by Brian Gregson.


Algae have been the subject of considerable concern around the Eel and Klamath rivers, because of harmful blooms.  Under low summer flows, cyanobacterial blooms in the Eel River have been linked to at least eleven dog deaths. But not all algae deserve a bad rap!  Yvonne Vadeboncoeur, who gave us a lecture on her work on algal grazing by cichlid fishes of the Great Lakes of Africa, has a saying: “Algae should be eaten and not seen”. We think of algae as harmful when they bloom, make a mess, deplete oxygen in water, and in some cases, produce toxins. Yet the “good” algae (those that are grazed down, so remain inconspicuous, heeding Yvonne’s admonition) supply most of the energy and nutrition that supports aquatic life in the Eel River (and other sunlit rivers and lakes worldwide). Diatoms that grow on rocks and on macro-algal streamers in the Eel are the most nutritious food available for our native frog tadpoles, snails and the grazing aquatic invertebrates that feed salmon and other fishes. Diatoms are rich in fats, synthesizing poly-unsaturated fatty acids critical to animals (like us) who need these “pufas” but can’t make them. We humans eat fish for health, but the healthy lipids actually come from diatoms and similar algae in the food chains that fueled fish growth. As Rex says, “Diatoms don’t smell fishy; fish smell diatomy”. Foray visitors and students get to learn which algae we animals need to thank (e.g. diatoms) and which algae (certain cyanobacteria) we and our livestock and pets need to avoid.

Paula plankton net

Paula Furey demonstrating use of phytoplankton tow net at off-channel pool near Jane (Marks’) rock bar on S. Fk. Eel.  photo by Mary Power.

The 2015 Foray participants arrived Thursday evening.  Friday, Saturday and Sunday we enjoyed discussions over meals prepared and served by Keith’s wife Lindsey, mother Wendy, and father Brian—thanks so much!   Friday morning, after orientation talks in the Environmental Science Center, we collected algae from the sunny mainstem South Fork Eel, from rock pools isolated near a wide bend in this mainstem, and sites on the darker tributary, Elder Creek. We then brought our whirl paks of algae to the lab for microscopy. Newcomers can be intimidated by looking down a microscope for the first time, but within hours, Rex and Paula have new algal initiates so entranced by the beauty and diversity they find in that micro-world that it can be difficult to get them to break for beer and dinner.

This year, we had great presentations and discussions from Rex, Paula, Yvonne, Keith, and guest lectures from Eli Asarian, Mike Deas, and Pat Higgins–folks who have watching the Eel and the Klamath river ecosystems for years. Pat Higgins and the Eel River Recovery Project volunteers have made many encouraging observations suggesting that river habitats as well as populations of salmon, steelhead, and even sturgeon have begun to recover from the massive logging era. Unfortunately, this recovery is threatened by erosion, pollution, and increased summer water extraction for expanding marijuana cultivation.  We need to understand how land and water use, climate, and ecological interactions can tip the Eel between cyanobacterially degraded and salmon-supporting states. Looking at the base of the food chain, at the algae that are eaten but not seen, versus those that are seen but not eaten, can guide us towards better understanding of how to keep rivers of Northern California on a trajectory towards ecological recovery.

A new crayfish may be invading the Eel, unfortunately.

On March 14 2015, Mary Power found a new crayfish in the South Fork Eel River, just north of the Angelo Coast Range Reserve on the eastern edge of the first pool below confluence of the South Fork Eel with Ten Mile Creek. Phil Georgakakos tentatively identified this as the non-native (invasive) red swamp crayfish, Procambarus clarkii ( Thanks to Sarah Kupferberg’s communications network, three crayfish experts quickly weighed in, supporting Phil’s identification. Phil and I found just the head and claws of this specimen—One expert expressed the hope that this crayfish had been eaten and tossed into the river. Although a human picnic seems unlikely, given the remote site, we can only hope this was the case~! We would be interested to hear if others see this new, intensely red, rather delicate (thin clawed) crayfish—with no “signal” white spots on its claws like the well-established (and possibly native) Pasifasticus leniusculus.

Ventral (bottom) view-the camera case is 12.5 cm long

the camera case is 12.5 cm long

Ring necked snakes

Ring necked snakes are brown on top, except for an orange ring, right behind their heads. Do snakes have necks?

But underneath (ventral side), ring-necks are right orange. In a defense display, this snake is starting to coil up the tip of its tail–the next stage is to wave it around like a head, hoping a predator will think it is.



Landscapes of Food and Fear–field ecology short course planned

Jeanine, Keith, Jim, Phil, Justin, Joel, and Mary in front of White House. photo by Kaitlyn Gaynor

On March 13-15 2015, Joel Brown (University of Illinois, Chicago), Jim Estes (UC Santa Cruz), and Justin Brashares and Mary Power (UC Berkeley) and five graduate students from the Power and the Brashares labs got together at Angelo to discuss behavioral, evolutionary, and community ecology, and our shared interest in animal foraging and food webs. Joel and Mary discussed plans (that they first started hatching over 10 years ago) for a future short field course on “Landscapes of Food and Fear”. Animals (and plants and microbes) must forage for resources that are scattered around a shifting, heterogeneous environment. As food availability varies, so too do hazards from predators and environmental stresses that foragers experience (e.g. temperature, wind). Foraging by any organism involves trading off the gains to be made by collecting food against the costs of doing so—“how to find lunch without becoming lunch”, as yet another food web ecologist, Mark Hay of Georgia Tech puts it. Food gradients and the ability of animals to harvest resources can be studied experimentally, but how do we assess the perception of risks held by creatures very different from ourselves?


Joel Brown and Phil Georgakakos, perched on a boulder in the middle of Ten Mile Creek, discuss ecology, food, and fear. photo by M. Power

Joel causes a ring necked snake, if not fear, then serious concern as he borrows him for a brief interaction. Standing left to right: Jim Estes, Jeanine Porzio, Kaitlyn Gaynor, Keith Bouma-Gregson, Justin Brashares, and Phil Georgakakos.

Joel, an evolutionary behavioral ecologist, has come up with a way to measure “the landscape of fear” for a wide range of animals. He reasoned that foragers should deplete food patches more thoroughly in areas they consider safe, where they could spend more time, and more of that time eating versus being vigilant. In patches they perceived as more dangerous, they might give up earlier, leaving behind more food. If food densities at various sites were initially similar before foraging occurred, the “Giving Up Density” (GUD) of food at a site after an animal quite foraging there might indicate how risky it considered that particular landscape position to be. Joel has devised ingenious experimental food patches tailored for particular types of animals (for example, squirrels get trays of sand mixed with fixed number of hidden nuts). standardized These patches can then be deployed along gradients of safety (e.g., for a squirrel, at the foot of a tree versus far from it). Joel and others have found that GUDs are good indices of how different species perceive their “Landscape of Fear”, and that you can learn a lot about how different species make the food-safety tradeoff that is relevant to their ecology, evolution, and potential futures on our changing planet.

Profs Joel Brown and Justin Brashares (ESPM, UCB) at Ten Mile Creek

Walk through the August 2014 Angelo burn, Jim Estes in the lead.

Joel and Justin on the hogback above the South Fork Eel-Ten Mile Creek confluence

Phil holding a southern alligator lizard

Joel and a Pacific tree toad


Some time in late spring 2017 or 2018 we hope to host Joel for a Landscape of Food and Fear workshop at Angelo–stay tuned. Part of the fun for participants will be to devise Joel-inspired “food patches” with simple materials that can show how diverse creatures (grasshoppers, ground squirrels, garter snakes, butterflies, deer) perceive hazard and opportunity along gradients and across thresholds in their environments. Making successful food patches for a given species requires 1) that you attempt to “get inside the head” of your focal organism, and 2) that you enjoy the arts and crafts of ingenious field gear innovation that is a big part of successful experimental field ecology.   Both are great fun.

Janine, Katlyn, Phil, and Keith at Ten Mile Creek



A new crayfish invading the Eel?

the camera case is 12.5 cm long

Ventral view: the camera case is 12.5 cm long


dorsal (back) view

On March 14 2015, Mary Power and Phil Georgakakos found a new crayfish in the South Fork Eel River, just north of the Angelo Coast Range Reserve on the eastern edge of the first pool below confluence of the South Fork Eel with Ten Mile Creek (~ long/lat). Phil tentatively identified this as the non-native (invasive) red swamp crayfish, Procambarus clarkii ( Crayfish experts quickly weighed in, thanks to communications from Sarah Kupferberg, supporting Phil’s identification. We found just the head and claws of this specimen—One expert expressed the hope that this had been eaten and tossed into the river. Although a human picnic seems unlikely, given the remote site, we can only hope~! We would be interested to hear if others see this strange, intensely red, rather delicate-looking crayfish—no “signal” white spots on its large claws.

Oscar and the Fox Creek Slime Mold

Photo by Mary Power

Photo by Mary Power

doesn’t smell like scrambled eggs…

Oscar and the giant slime mold

Oscar Chang and I encountered this bright yellow spongy mass on a mossy rotten log on the south (left looking downstream) bank of Fox Creek, about 50 m up from the confluence with South Fork, in early June 2013, when we were helping Hiromi Uno install her mayfly-trout experiment. The vivid slime mold color got our attention! Slime molds, considered protists like ameoba even though they are societies rather than single celled organisms, deserve our attention. Some very clever Japanese scientists have made them seek food through mazes, and found out that foraging slime molds could eventually optimize traffic patterns through some major cities of the world—check out slime mold foraging here: