Do not fill out this information. 

On this particular page, the Initial Text and Image fields for this template are not used (inactive).  A Carousel Slideshow is displayed instead. 

To edit the Carousel Slideshow, Choose Edit Existing >  Carousel Slides.  Then navigate to your CZO's entry entitled "Research"

Goal 1
DEVELOP A UNIFYING THEORETICAL FRAMEWORK of critical zone evolution that integrates physical, chemical, and biological processes.


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.

Conceptual Models >


Goal 2
DEVELOP COUPLED SYSTEMS MODELS to explore how critical zone services respond to anthropogenic, climatic, and tectonic forcings.


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.

Numerical Models >


Goal 3
DEVELOP INTEGRATED, EXTENSIVE DATASETS that document a wide range of critical zone settings, including geology and climate.


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.

Data >


Fundamental Questions

Despite the Critical Zone's importance to terrestrial life and many environmental issues, it remains poorly understood. Key questions include:

  • How does the Critical Zone form?
  • How does it operate?
  • How does it evolve?

There are many followup questions as well. For example:

  • How will the Critical Zone respond to projected climate and land use changes?
Specific Questions

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:

  • What is the legacy of climate and geologic history in critical zone architecture?
     - Boulder
  • How does variability in energy input and related mass flux influence critical zone structure and function?
      - Jemez-Catalina
  • How does saprolite advance vary with regolith thickness and landscape position?
     - Luquillo
  • How does water sculpt a landscape on shale bedrock?
     - Shale Hills
  • How does landscape variability control how soil moisture, evapotranspiration and streamflow respond to snowmelt and rainfall?
     - Southern Sierra
Cross-CZO Questions

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:

  • How do processes that nourish ecosystems change over human and geologic time scales?
  • How do biogeochemical processes govern long-term sustainability of water and soil resources?
  • What processes control fluxes of carbon, particulates, and reactive gases over different timescales?
  • How do variations in and perturbations to chemical and physical weathering processes impact the Critical Zone?

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.

Cross-CZO studies >


Our Approach

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.

Interdisciplinary & Multidisciplinary

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.

Multiple Disciplines >


A Common Infrastructure

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.

Infrastructure >


  Community & Collaboration

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.

Partner Organizations >


Predictive Ability

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:

  • Broad knowledge of the complex physical, chemical, and biological processes of the Critical Zone
  • The ability to describe interactions between the varied climatic and geologic factors that distinguish different regions.
  • Advances in theory, modeling, and measurement.

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. 

Read: Future Directions for CZO Science >

Models >



See Multiple Disciplines

See Infrastructure

See Partner Organizations


Research News

FEATURED NATIONALLY

What Causes Ecological Shifts?

17 Oct 2017 (IML) - A new information partitioning methodology allows researchers to identify the factors that drive behavior in an ecohydrologic system.

FEATURED NATIONALLY

Stories in the Soil

17 Oct 2017 (IML) - A series of field experiments in the U.S. Midwest is investigating how past, present, & future human activities and climate affect the health of soil.

FEATURED NATIONALLY

Comment by 05 Nov on draft report of 2017 CZ Science Meeting in Arlington, VA

17 Oct 2017 (National) - Contribute to public discussion of a draft report: “New Opportunities for Critical Zone Science” based on the June 2017 Arlington CZO meeting.

FEATURED NATIONALLY

Register for hands-on, pre-AGU workshop:  Distributed temperature and acoustic sensing (DTS/DAS)

05 Oct 2017 (National) - NSF's CTEMPs offers a two-day hands-on workshop on distributed fiber sensing. 9-10 Dec. Limited to 30 participants. Register soon!

FEATURED NATIONALLY

NSF News Release: Changes in non-extreme precipitation may have not-so-subtle consequences

18 Sep 2017 (National, IML) - Analysis of more than five decades of data leads to new conclusions

FEATURED NATIONALLY

NSF News Release: What’s killing trees during droughts? Scientists have new answers.

14 Aug 2017 (National, Catalina-Jemez) - Researchers find that carbon starvation and hydraulic failure kill drought-stricken trees.


FEATURED

82nd Annual Field Conference of PA Geologists tour the CZO

05 Oct 2017 (Shale Hills) - Just under 250 geologists from across the state of Pennsylvania spent three days (Oct 5-7) exploring outcrops and research sites in Blair, Centre...

Hurricane Maria decimated the nation’s only tropical rain forest outside Hawaii

05 Oct 2017 (Luquillo) - Hurricane Maria ravaged Puerto Rico. The Category 4 storm destroyed thousands of homes, businesses, bridges, communication towers, the entire...

Researchers Set a Rainforest to Bake

05 Oct 2017 (Luquillo) - The world’s rainforests absorb 30 percent of human-produced carbon dioxide. Plants take up the CO2 through photosynthesis and release it...

New SSCZO comic artfully communicates research

19 Jul 2017 (Sierra) - Wonder what soils and sponges have in common? Or why some trees in the Sierra Nevada are dying while others are surviving? Find out in our new comic.

FEATURED

NSF Discovery: Can an ancient ocean shoreline set the stage for a tropical forest of today?

13 Jul 2017 (National, Luquillo) - Researchers at NSF Critical Zone Observatory and Long-Term Ecological Research sites are finding out.

More News >


Example Publications

FEATURED NATIONALLY

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)

FEATURED NATIONALLY

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

FEATURED NATIONALLY

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

FEATURED NATIONALLY

A multi-species synthesis of physiological mechanisms in drought-induced tree mortality. Adams H.D., Zeppel M.J.B., Anderegg W.R.L., Hartmann H., Landhausser S.M., Tissue D.T., Huxman T.E., Hudson P.J., Franz T.E., Allen C.D., Anderegg L.D.L., Barron-Gafford G.A., Beerling D.J., Breshears D.D., Brodribb T.J., Bugmann H., Cobb R.C., Collins A.D., Dickman L.T., Duan H., Ewers B.E., Galiano L., Galvez D.A., Garcia-Forner N., Gaylord M.L., Germino M.J., Gessler A., Hacke U.G., Hakamada R., Hector A., Jenkins M.W., Kane J.M., Kolb T.E., Law D.J., Lewis J.D., Limousin J-M., Love D.M., Macalady A.K., Marti­nez-Vilalta J., Mencuccini M., Mitchell P.J., Muss J.D., O'Brien M.J., O'Grady A.P., Pangle R.E., Pinkard E.A., Piper F.I., Plaut J.A., Pockman W.T., Quirk J., Reinhardt K., Ripullone F., Ryan M.G., Sala A., Sevanto S., Sperry J.S., Vargas R., Vennetier M., Way D.A., Xu C., Yepez E.A., and McDowell N.G. (2017): Nature Ecology & Evolution 1: 1285–1291 (Catalina-Jemez)

FEATURED NATIONALLY

Growing new generations of critical zone scientists. Adam S. Wymore, Nicole R. West, Kate Maher, Pamela L. Sullivan, Adrian Harpold, Diana Karwan, Jill A. Marshall, Julia Perdrial, Daniella M. Rempe, Lin Ma (2017): Earth Surface Processes and Landforms (National, Luquillo) Cross-CZO National


The temperature response surface for mortality risk of tree species with future drought. Adams H.D., Barron-Gafford G.A., Minor R.L., Gardea A.A., Bentley L.P., Law D.J., Breshears D.D., McDowell N.G., Huxman T.E. (2017): Environmental Research Letters (accepted) (Catalina-Jemez)

FEATURED

Photosynthetic phenological variation may promote coexistence among co-dominant tree species in a Madrean sky island mixed conifer forest. Potts D.L., Minor R.L., Braun Z., Barron-Gafford G.A. (2017): Tree Physiology 37(9): 1229–1238 (Catalina-Jemez)

Dual-phase mass balance modeling of small mineral particle losses from sedimentary rock-derived soils . Bern, Carleton R. and Yesavage, Tiffany (2017): Chemical Geology (in review) (Shale Hills)

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 (Eel)

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 (Eel)

A reactive transport model for Marcellus shale weathering. Heidari, P., Li Li, Lixin Jin, Jennifer Z. Williams, and Susan L. Brantley (2017): Geochimica et Cosmochimica Acta, 217:421-440 (Shale Hills)

FEATURED

Patterns of change in high frequency precipitation variability over North America. Roque-Malo, S. and Kumar, P. (2017): Nature.com (IML)

More Publications >