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.
04 Jan 2018 (National) - The LTER Network Communications Office is pleased to announce a new webinar series hosted by the NCO and the National Center for Ecological Analysis...
02 Jan 2018 (National, IML) - Call for papers for “Dynamics in Intensively Managed Landscapes: Water, Sediment, Nutrient, Carbon, and Ecohydrology”
01 Jan 2018 (National, Boulder, Calhoun, Catalina-Jemez, Christina, Eel, IML, Luquillo, Reynolds, Shale Hills, Sierra) - New Opportunities for Critical Zone Science Following the June 2017 Arlington Meeting for Critical Zone Science (hosted by CZO), a white booklet...
08 Feb 2018 (Boulder) - The CZO's own Dr. Noah Molotch, director of CWEST, appeared on KGNU during a piece on snow depth and Snow Telemetry (SNOTEL). KGNU is an...
22 Jan 2018 (Luquillo) - On Saturday, January 13, we successfully held our third Teacher Data Jam Workshop of the Luquillo LTER Schoolyard Program. On this occasion,...
18 Jan 2018 (Sierra) - Meet the people behind the research!
17 Jan 2018 (Sierra) - Funding opportunities, recent publications, upcoming webinars, and other important information for southern Sierra researchers
17 Jan 2018 (Sierra) - Dr. Roger Bales's Nye Lecture, "Making up for lost snow: lessons from a warming Sierra Nevada", is now available to watch online.
Humidity determines snowpack ablation under a warming climate. Harpold A.A. and Brooks P.D. (2018): PNAS 115(6): 1215-1220 (Boulder, Catalina-Jemez) Cross-CZO
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 (online) (Calhoun, Catalina-Jemez, Christina, Eel, Luquillo, Sierra) Cross-CZO
Concentration-Discharge Relations in the Critical Zone: Implications for Resolving Critical Zone Structure, Function and Evolution. Chorover, J., Derry, L. A., McDowell, W. H. (2017): Water Resources Research 53(11): 8654–8659 (National, Catalina-Jemez, Luquillo, Shale Hills) 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 (National, Boulder, Calhoun, Catalina-Jemez, Eel, IML, Luquillo, Reynolds, Shale Hills, Sierra) Cross-CZO National
Hydrogeomorphological differentiation between floodplains and terraces. Qina Yan, Toshiki Iwasaki, Andrew Stumpf, Patrick Belmont, Gary Parker, Praveen Kumar (2017): Earth Surface Processes and Landforms (IML)
Regional sensitivities of seasonal snowpack to elevation, aspect, and vegetation cover in western North America. Christopher J. Tennant, Adrian A. Harpold, Kathleen Ann Lohse, Sarah E. Godsey, Benjamin T. Crosby, Laurel G. Larsen, Paul D. Brooks, Robert W. Van Kirk, Nancy F. Glenn (2017): Water Resources Research 53 (National, Boulder, Catalina-Jemez, Reynolds, Sierra) Cross-CZO National
Impacts of hydraulic redistribution on grass–tree competition vs facilitation in a semi-arid savanna. Barron-Gafford G.A., Sanchez-Cañete E.P., Minor R.L., Hendryx S.M., Lee E., Sutter L.F., Tran N., Parra E., Colella T., Murphy P.C., Hamerlynck E.P., Kumar P. and Scott R.L. (2017): New Phytologist 215(4): 1451–1461 (Catalina-Jemez, IML) Cross-CZO
Mechanisms controlling the impact of multi-year drought on mountain hydrology. Bales, R. C.; Goulden, M. L.; Hunsaker, C. T.; Conklin, M. H.; Hartsough, P. C.; O'Geen, A. T.; Hopmans, J. W.; Safeeq, M. (2018): Hydrological Processes: 10.1038/s41598-017-19007-0 (Sierra)
Subsurface plant-accessible water in mountain ecosystems with a Mediterranean climate. Klos, P. Z.; Goulden, M.; Riebe, C. S.; Tague, C.; O’geen, A. T.; Flinchum, B. A.; Safeeq, M.; Conklin, M. H.; Hart, S. C.; Berhe, A. A.; Hartsough, P. C.; Holbrook, S.; Bales R. C.; (2018): Hydrological Processes: 10.1002/wat2.1277 (Sierra)
Flow Resistance Interactions on Hillslopes With Heterogeneous Attributes: Effects on Runoff Hydrograph Characteristics. Papanicolaou, A.N., Abban, B., Dermisis, D., Giannopoulos, C., Flanagan, D., Frankenberger, J., and Wacha, K. (2018): Water Resources Research (IML)
Anthropocene Landscape Change and the Legacy of Nineteenth- and Twentieth-Century Mining in the Fourmile Catchment, Colorado Front Range. Dethier, D. P., Ouimet, W. B., Murphy, S. F., Kotikian, M., Wicherski, W., & Samuels, R. M. (2018): Annals of the American Association of Geographers, 1-21 (Boulder)
Nutrient foraging by mycorrhizas: From species functional traits to ecosystem processes. Chen, Weile, Koide, Roger T., and Eissenstat, David M. (2018): Functional Ecology, 00:1–12 (Shale Hills)
Engaging over data on fracking and water quality. Brantley, S.L., Vidic, R.D., Brasier, K., Yoxtheimer, D., Pollak, J., Wilderman, C., and Wen, T. (2018): Science, 359 (6374): 395-398 (Shale Hills)
Flow Resistance Interactions on Hillslopes With Heterogeneous Attributes: Effects on Runoff Hydrograph Characteristics. Papanicolaou, A.N., Abban, B.K., Dermisis, D.C., Giannopoulos, C.P., Flanagan, D.C., Frankenberger, J.R., and Wacha, K.M. (2018): Water Resources Research (IML)