Fig 1. The critical zone of vegetation (green), soil and weathered bedrock with perched water table (red to blue), overlying fresh bedrock (grey) that exchanges currencies (arrows) with atmosphere (cloud) and mediates effluents (curved arrow) to a channel network (lines) which drain to ocean (blue triangle).
California's Eel River Critical Zone Observatory is rooted in intensive field monitoring in the critical zone, which follows watershed currencies (water, solutes, gasses, biota, sediment, energy, and momentum) through a subsurface physical environment and microbial ecosystem of the critical zone into the terrestrial ecosystem, up into the atmosphere, and out through drainage networks to the coastal ocean (Figure 1).
Soil, forest, and riverine ecosystems interact with these currencies, mediating the delivery of nutrients to the sea. CZO investigations will co-evolve with a synthesis model that mechanistically links the critical zone to atmospheric processes, watershed routing, ecosystems dynamics, stream flow, and coastal processes in order to investigate fundamental questions and to provide a modeling tool for management issues.
Our observatory operates at four distinct scales: 1) the hillslope (our critical zone workshop), 2) the stream reach (where critical zone currencies dictate water supply, extent of wetted channel, and the emergent aquatic ecosystem), 3) the whole watershed scale (nearly 10,000 km2), and 4) the regional scale (>13,000 km2). Read more about our field areas.
Motivated by anticipated increase in climate extremes (especially extended drought) and accelerating societal demand for water, we focus on filling knowledge gaps that not only inhibit our ability to forecast the magnitude of future change of systems, but even the sign of that change. We are also developing a modular coupled model (AWESOM) which will provide local predictions over a regional scale and that can be used to ask “what if” questions about possible future climate and landuse scenarios and the consequences on runoff and ecosystem states.
10 May 2018 - The Discoveries section of the National Science Foundation's website on Critical Zone Observatories (CZOs).
02 Mar 2018 - A recent paper on rock moisture by Danielle Rempe and Bill Dietrich of the Eel River CZO is been featured on NSF News site, SF Chronicle, others
21 Mar 2016 - The following is part nine in a series on the National Science Foundation's Critical Zone Observatories (CZO) Network.
18 Feb 2016 - Science isn’t generally considered an extreme sport, but you wouldn’t know that by watching researchers in the Eel River Critical Zone Observatory.
29 Jul 2015 - Eel River CZO ecohydrologist Sally Thompson and ecologists Stephanie Carlson and Mary Power worked with The Nature Conservancy to explore the...
17 Jul 2015 - An Organized Session On Critical Zone Ecology At The 100th Annual Meeting Of The Ecological Society Of America August 9-14, 2015 In Baltimore, Md.
19 Mar 2015 - Get a sense of the people and the work. Several members of the Eel River CZO are profiled here, including students and professors.
19 Nov 2018 - The 2018 AGU Fall Meeting will be held December 10-14 in Washington, D.C.
06 Nov 2018 - Marshall Receives 2018 Luna B. Leopold Young Scientist Award
01 Jan 2018 - New Opportunities for Critical Zone Science Following the June 2017 Arlington Meeting for Critical Zone Science (hosted by CZO), a white booklet...
05 Dec 2017 - Information on CZO award recipients, events, presentations, etc. at the 2017 AGU Fall Meeting.
30 Oct 2017 - Water Resources Research published a new special collection in September 2017 featuring concentration-discharge research from multiple CZOs.
Mercury sourcing and sequestration in weathering profiles at six Critical Zone Observatories. Richardson, Justin B., Arnulfo A. Aguirre, Heather L. Buss, A. Toby O'Geen, Xin Gu, Daniella M. Rempe, and Daniel deB. Richter (2018): Global Biogeochemical Cycles, doi: 10.1029/2018GB005974 Cross-CZO National
Quantification of the seasonal hillslope water storage that does not drive streamflow. Dralle, D.N., Hahm, W.J., Rempe, D.M., Karst, N.J., Thompson, S.E., Dietrich, W.E. (2018): Hydrological Processes
Controls on the distribution and resilience of Quercus garryana: ecophysiological evidence of oak's water‐limitation tolerance. Hahm, W.J., Dietrich, W.E., and Dawson, T.E. (2018): Ecosphere 9 (5)
Widespread anatoxin-a detection in benthic cyanobacterial mats throughout a river network. Bouma-Gregson, K., Kudela, R.M., Power, M.E. (2018): PLoS One
Beyond clay: towards an improved set of variables for predicting soil organic matter content. Rasmussen C., Heckman K., Wieder W.R., Keiluweit M., Lawrence C.R., Berhe A.A., Blankinship J.C., Crow S.E., Druhan J.L., Hicks Pries C.E., Marin-Spiotta E., Plante A.F., Schädel C., Schimel J.P., Sierra C.A., Thompson A., Wagai R. (2018): Biogeochemistry 137(3): 297–306 Cross-CZO
Climatic, ecophysiological, and phenological controls on plant ecohydrological strategies in seasonally dry ecosystems. Vico, Giulia Thompson, Sally E. Manzoni, Stefano Molini, Annalisa Albertson, John D. Almeida-Cortez, Jarcilene S. Fay, Philip A. Feng, Xue Guswa, Andrew J. Liu, Hu Wilson, Tiffany G. Porporato, Amilcare (2015): Ecohydrology 8(4): 660-681.
The Thirsty Eel: Summer and Winter Flow Thresholds that Tilt the Eel River of Northwestern California from Salmon-Supporting to Cyanobacterially Degraded States. Power, M.E., Bouma-Gregson, K., Higgins, P. and Carlson, S.M. (2015): Copeia 1:200-211.
High Time for Conservation: Adding the Environment to the Debate on Marijuana Liberalization. Carah, J., Howard, J., Thompson, S.E., Short Gianotti, A.G., Bauer, S., Carlson, S.M., Dralle, D.N., Gabriel, M.W., Hulette, L., Johnson, B., Knight, C., Kupferberg, S., Martin, S., Naylor, R., Power, M.E. (2015): BioScience (Advance Access)
A bottom-up control on fresh-bedrock topography under landscapes. Rempe, D.M., Dietrich, W.D. (2014): Proceedings of the National Academy of Sciences 111 (18): 6576-6581
Data paper: 31 Years of Spatially Distributed Air Temperature, Humidity, Precipitation Amount and Precipitation Phase From Reynolds Critical Zone Observatory. Kormos, P. R., Marks, D. G., Seyfried, M. S., Havens, S. C., Hedrick, A., Lohse, K. A., Sandusky, M., Kahl, A. and Garen, D. (2018): ESSD. 10, 1197-1205 Cross-CZO
Direct observations of rock moisture, a hidden component of the hydrologic cycle. Rempe, D. and Dietrich, W.E. (2018): Proceedings of the National Academy of Sciences
The influence of mixing on stable isotope ratios in porous media: A revised Rayleigh model. Druhan J.L, Maher K. (2017): Water Resources Research, 53, 1101–1124 Cross-CZO National
Growing new generations of critical zone scientists. Wymore, Adam S., Nicole R. West, Kate Maher, Pamela L. Sullivan, Adrian Harpold, Diana Karwan, Jill A. Marshall, Julia Perdrial, Daniella M. Rempe and Lin Ma (2017): Earth Surface Processes and Landforms 42 (14): 2498-2502 Cross-CZO National
Event-scale power law recession analysis: quantifying methodological uncertainty. Dralle, D. N., Karst, N. J., Charalampous, K., Veenstra, A., and Thompson, S. E. (2017): Hydrology and Earth System Sciences 21:65-81
Rise and fall of toxic benthic freshwater cyanobacteria (Anabaena spp) in the Eel river: Buoyancy and dispersal. Bouma-Gregson, K., Power, M.E., and Bormans, M. (2017): Harmful Algae 66: 79-87
Designing a network of critical zone observatories to explore the living skin of the terrestrial Earth. Brantley, S.L., McDowell, W.H., Dietrich, W.E., White, T.S., Kumar, P., Anderson, S., Chorover, J., Lohse, K.A., Bales, R.C., Richter, D., Grant, G., and Gaillardet, J. (2017): Earth Surface Dynamics, 5, 841–860 Cross-CZO National