The CZOS are working toward a holistic conceptual model of critical zone evolution that couples hydrological, geochemical, geomorphic, and biological processes. Such a model must consider many spatial and temporal scales.
The CZOs are building systems models that quantitatively combine multiple processes, often spanning an entire watershed. These models typically track fluxes and storage of energy, water, carbon, sediments, and/or other materials.
The CZOs are assembling the needed infrastructure for an integrated data/ measurement foundation. This foundation will inform our theoretical framework, constrain our models, and help test hypotheses across CZOs.
Despite the Critical Zone's importance to terrestrial life and many environmental issues, it remains poorly understood. Key questions include:
There are many followup questions as well. For example:
Each Critical Zone Observatory is helping work on these fundamental questions along with numerous others. Some questions are specific to the unique characteristics of their field site and the talents of their collaborative research team. Some examples:
A key advantage of the coordinated system of Critical Zone Observatories is that it can address the biggest questions by leveraging differing environments and histories. More specifically, cross-CZO science can begin to answer questions such as:
An expressed goal of the CZO program is to catalyze transformative Earth surface science in the coming decade by developing cross-site science that helps to establish: 1) a unifying theory of CZ evolution; 2) coupled systems models to explore how CZ services respond to anthropogenic, climatic, and tectonic forcing; and 3) data sets that document differing CZ geologic and climatic settings, inform the theoretical framework, constrain conceptual and coupled systems models, and test model-generated hypotheses.
Answering fundamental questions requires much better knowledge of how physical, chemical, and biological processes in the Critical Zone are coupled and at what spatial and temporal scales. Many of these processes are highly non-linear and can range across vast scales - from atomic to global, and from seconds to eons.
To better understand how the complex processes of the Critical Zone are linked, the U.S. NSF National CZO Program employs a systems approach across a broad array of sciences. This interdisciplinary and multidisciplinary approach integrates many disciplines, especially in the geological and biological sciences. Examples include hydrology, ecology, biogeochemistry, and geomorphology.
Our systems approach across disciplines is well supported via our infrastructure. Our nine observatories span a range of climatic, geologic, and physiographic environments, from California to Puerto Rico. Each CZO is working toward a common set of resources, which will enable comparison of whole-watershed energy and mass balances across a variety of settings.
Within each CZO, scientific collaborations are common, often bringing together researchers from different institutions and crossing disciplinary boundaries. This team-based approach helps foster a strong community, which is further strengthed by graduate student involvement. Similar collaborations occur between investigators and students at different CZOs as well as with members of other US science programs. Moreover, the US CZO program also works with an international network of Critical Zone investigators and research sites.
An immediate challenge is to develop a robust predictive ability for how the structure and function of the Critical Zone evolves, including how it will respond to projected climate and land-use changes. This predictive ability must be founded on:
Over the next decade, the CZO program will produce a fundamental understanding and four-dimensional data sets that will stimulate, inspire, and test the resulting predictive models.
22 Jun 2017 (National, IML) - Corn is grown not only for food; it is also used as an important renewable energy source. But renewable biofuels can come with hidden economic and env
21 Jun 2017 (National, Sierra) - University of California Television (UCTV) features Bales, Conklin, Glaser, Safeeq, and others on the new Sustainable California channel
21 Jun 2017 (National, IML) - Scientists obtain comprehensive view of agricultural ecosystems
21 Apr 2017 (National, Boulder, Calhoun, Catalina-Jemez, Christina, Eel, Luquillo, Reynolds, Shale Hills, Sierra) - AGU has published a collection of commentaries highlighting the important role Earth and space science research plays in society.
17 Apr 2017 (IML) - What's good for crops is not always good for the environment. Nitrogen, a key plant nutrient, can cause problems when it leaches into water supplies.
06 Apr 2017 (National, Boulder, Calhoun, Catalina-Jemez, Christina, Eel, IML, Luquillo, Reynolds, Shale Hills, Sierra) - 2017 CZO Webinar Series: Critical Zone and Society.
28 Mar 2017 (Sierra) - NSF Press Release: New research finding provides insight into role dust may play as ecosystems change
25 Jun 2017 (Eel) - Eel River CZO researchers are featured in a new video at the Lawrence Hall of Science.
22 Jun 2017 (IML) - Civil and environmental engineering professor Praveen Kumar and graduate student Meredith Richardson published their findings in the journal Earth’s F
25 May 2017 (Shale Hills) - Joanmarie Del Vecchio, MS Candidate in Geosciences, delivered an engaging public presentation on her thesis research "A Record of Coupled Hillslope...
25 May 2017 (Boulder) - Research Experience for Community College Students program inspires budding Colorado scientists
04 May 2017 (Sierra) - Onward California - University of California television spots showcase Southern Sierra CZO research
Critical Zone services as environmental assessment criteria in intensively managed landscapes. Richardson, M., and Kumar, P. (2017): Earth's Future (IML)
Geochemical evolution of the Critical Zone across variable time scales informs concentration-discharge relationships: Jemez River Basin Critical Zone Observatory. McIntosh J.C., Schaumberg C., Perdrial J., Harpold A., Vázquez-Ortega A., Rasmussen C., Vinson D., Zapata-Rios X., Brooks P.D., Meixner T., Pelletier J., Derry L., Chorover J. (2017): Water Resources Research 53(5): 4169–4196 (National, Boulder, Catalina-Jemez, Luquillo, Reynolds, Shale Hills) Cross-CZO National
Quantifying and Managing Soil Functions in Earth's Critical Zone Combining Experimentation and Mathematical Modelling. Steven A. Banwart and Donald L. Sparks (2017): Advances in Agronomy, Volume 142, Pages 2-423 (2017) (National) National
Integrated Interdisciplinary Science of the Critical Zone as a Foundational Curriculum for Addressing Issues of Environmental Sustainability. Timothy White, Adam Wymore, Ashlee Dere, Adam Hoffman, James Washburne, and Martha Conklin (2017): Journal of Geoscience Education Vol. 65, No. 2, pp. 136-145 (National) National
Topographically driven differences in energy and water constrain climatic control on forest carbon sequestration. Swetnam T.L., Brooks P.D., Barnard H.R., Harpold A.A., and Gallo E.L. (2017): Ecosphere 8(4): e01797 (Boulder, Catalina-Jemez) Cross-CZO
Prevalence and magnitude of groundwater use by vegetation: a global stable isotope meta-analysis. Jaivime Evaristo and Jeffrey J. McDonnell (2017): Scientific Reports 7 (National, Catalina-Jemez, Sierra) Cross-CZO National
Enhancing Interoperability and Capabilities of Earth Science Data using the Observations Data Model 2 (ODM2). Hsu, Leslie, Emilio Mayorga, Jeffery S. Horsburgh, Megan R. Carter, Kerstin A. Lehnert and Susan L. Brantley (2017): Data Science Journal, 16: 4, pp. 1–16 (National, Shale Hills) Cross-CZO National
Expanding the role of reactive transport models in critical zone processes. Li Li, Kate Maher, Alexis Navarre-Sitchler, JennyDruhan, Christof Meile, Corey Lawrence, Joel Moore, Julia Perdrial, Pamela Sullivan, Aaron Thompson, Lixin Jin, EdwardW. Bolton, Susan L. Brantley, William E. Dietrich, K. Ulrich Mayer, Carl I. Steefel, Albert Valocchi, John Zachara, Benjamin Kocar, Jennifer Mcintosh, Benjamin M. Tutolo, Mukesh Kumar, Eric Sonnenthal, Chen Bao, Joe Beisman (2017): Earth-Science Reviews, 165:280-301 (Calhoun, Catalina-Jemez, Eel, Shale Hills) Cross-CZO
Controls on deep critical zone architecture: a historical review and four testable hypotheses. Riebe, C. S., Hahm, W. J., Brantley, S. L. (2017): Earth Surface Processes and Landforms, 42 (1): 128–156 (National, Luquillo, Shale Hills, Sierra) Cross-CZO National
Extreme storms drive riverine particulate organic matter export from tropical mountians of estern Puerto Rico. Kathryn E. Clark, Robert F. Stallard, Martha A. Scholl, Alain F. Plante, Sheila F. Murphy, Grizelle Gonzalez, and William H. McDowell (2017): ... (Luquillo)
Geochemical evolution of the Critical Zone across variable time scales informs concentration-discharge relationships: Jemez River Basin Critical Zone Observatory. McIntosh J.C., Schaumberg C., Perdrial J., Harpold A., Vázquez-Ortega A., Rasmussen C., Vinson D., Zapata-Rios X., Brooks P.D., Meixner T., Pelletier J., Derry L., Chorover J. (2017): Water Resources Research. 53(5): 4169–4196 ()
A model of three-dimensional topographic stresses with implications for bedrock fractures, surface processes, and landscape evolution. Moon, S., J.T. Perron, S.J. Martel, W.S. Holbrook, and J. St. Clair (2017): Journal of Geophysical Research: Earth Surface 122 (4): 823-846 (Boulder, Calhoun) Cross-CZO
Multiple outflows, spatial components, and nonlinearities in age theory. Calabrese, S., and Porporato, A. (2017): Water Resources Research, 53 (1): 110-126 (Calhoun)
On the dynamic smoothing of mountains. Bonetti, S., and Porporato, A. (2017): Geophysical Research Letters, in press (Calhoun)
Spatial patterns of tree and shrub biomass in a deciduous forest using leaf-off and leaf-on LiDAR. Brubaker Kristen M., Johnson Quincey K., and Kaye Margot W. (2017): Canadian Journal of Forest Research (submitted) (Shale Hills)
Root morphology and mycorrhizal type strongly influence root production in nutrient hot spots of mixed forests . Chen W, Koide RT, Eissenstat DM (2017): Journal of Ecology (Shale Hills)