Current Projects:

PIs: Nichole Barger, University of Colorado
Akasha Faist, University of Colorado

BLM Canyon Country Fire Zone Collaborators:
Gabe Bissonettte Jason Kirks Funding Source: State of Utah, Department of Natural Resources,

Division of Wildlife Resources Time Period: 5/16 – 5/17

PIs: Nichole Barger, University of Colorado Michael Cramer, University of Cape Town Walter Tschinkel, Florida State University Funding Source: National Geographic Society Time Period: 5/14 – 5/17 Fairy circles are large (i.e. 3 -10 m diameter), circular, barren patches which are only found within specific areas of the desert grasslands of southern Angola, Namibia, and northern South Africa. These striking and enigmatic patterns have engaged the interest of scientists over the past four decades, but also represent a fascinating and unsolved mystery that has engaged the interest of the general public. Our objective is to conduct the first longer-term (i.e. 4 year) empirical tests of two recently published theories for the origin of fairy circles. Our hypothesis is that fairy circles are the product of vegetation spatial patterning and that soil fauna (i.e. termites) may contribute to their maintenance but not genesis. We will conduct multi-year experiments that alleviate water, nutrient, and seed limitation within fairy circles in order to test their effect on the spatial vegetation patterning. A second experiment will test the leading soil fauna hypothesis by removing soil termites from fairy circles. The logic of these experiments is as follows: if factors such as plant resources or soil fauna are indeed the proximate causes of fairy circles, then supplementing plant limiting resources or removing soil fauna should cause fairy circles to fill in and disappear. The broader importance of our research is that as intensified land use has degraded lands across many dryland regions, it has become increasingly important to understand the drivers and ecological consequences of vegetation patterning in these environments.

PI: Nichole Barger, University of Colorado

Co-PI: Ferran Garcia-Pichel (ASU), Matthew Bowker (NAU), Jayne Belnap (USGS)

Co-PI: Mike Duniway (USGS), and Sasha Reed (USGS)

Funding Source: SERDP, Strategic Environmental Research and Development

Time Period: 3/1/13 - 2/29/18

        Biological soil crusts ('biocrusts') are communities of microorganisms that develop on soil surfaces and are a critically important functional component of dryland systems of the globe. They are often associated with increased soil nutrient and water retention—resources that are highly limiting to plant productivity in these ecosystems. But most importantly, biocrusts stabilize soil surfaces against wind and water erosion. While resilient to wind and water erosion, biocrusts are highly susceptible to compressional forces, such as those generated from foot and vehicle traffic associated with ground-based military training activities. Due to the functional importance of biocrust communities to the ecological functioning of dryland ecosystems there is keen interest in restoring these communities. Thus our overarching research objective in this project is to facilitate the recovery of degraded arid and semi-arid Department of Defense (DoD) lands by restoring biocrust communities. In this project we will: 1) establish a biocrust nursery as an inoculum testing and supply center for biocrust restoration 2) identify successful field application methods of biocrust inoculum in a series offield trials 3) evaluate soil and plant responses to biocrust restoration in multi-factorial field experiments and 4) share knowledge of biocrust restoration success and challenges with DoD and federal land managers.

Past Projects:

PIs: Jason Neff, Nichole Barger, Lisa Dilling, Jana Milford

Funding source: Funded by USDA in a joint NASA/USDA call in Carbon Cycle Science, Research Opportunities in Space and Earth Sciences

Time Period: 5/2011 - 4/2015

In this project we take an integrated multi-scale approach to the evaluation of carbon stocks and fate under different management on public lands in the Intermountain West.   We developed this project in close collaboration with the US Department of Agriculture (USDA) Forest Service and the Department of Interior (DOI) Bureau of Land Management.  There are four primary objectives in our work and these are 1) the Analysis of forest and woodland carbon stocks across elevational gradients in Southwest Colorado and Eastern Utah, 2) the Evaluation of changes in forest and woodland carbon associated with land management activities including fire mitigation, and forestry, 3) the Projection of management impacts on carbon balance using ecosystem carbon models, and 4) the Integration of carbon into land management decisions including evaluation of potential implications of different federal approaches to carbon management.   The work uses remote sensing and field biomass measurements to develop regional carbon maps for federal land management centers in Colorado and Utah. At these sites, we also monitor changes in carbon stocks with management using ground based, data-collection techniques and use existing USFS models of forest biomass change to project carbon accumulation through time.  In all of our analysis, monitoring, and modeling work, we deal directly and explicitly with error and uncertainty and all spatial or temporal projections of carbon will include uncertainty bounds.  Finally this study includes the development of new decision support tools for carbon management that will reside in federal land management databases at our study sites.  We recognize that federal carbon management policy and interaction with existing land management policy is uncertain and likely to remain so for some time to come.  Accordingly, our study includes not just the development of decision support tools but also an explicit study of decision-making.  This project will help to identify the barriers and complexities involved in integration of carbon management into broader federal land management goals.

United States PIs: Dr. Jason Neff, Geosciences Department, CU Boulder Dr. Nichole Barger, Ecology and Evolutionary Biology, CU Boulder South Africa

Collaborating Scientist: Dr. John Stockton, Department of Geological Sciences, University of Cape Town

Funding Source: Mellon Foundation Time Period: 8/2008 - 10/2013        

In this project we outline a study of nitrogen (N) cycling across the diverse flora of the Western Cape province of South Africa.  This region of South Africa has a remarkable diversity of floral assemblages that are arrayed across (and associated with) an equally diverse collection of geologic settings.  We propose a study of nitrogen inputs and cycling that will be closely tied to an ongoing NRF funded study led by John Stockton of the University of Cape Town that is focused on understanding the role of geologic and geochemical variation in the control of floral composition in this region. This current project is oriented around the study of the inputs and cycling of macro and micronutrients (excluding N) in ecosystems that range from the Strandveld coastal ecosystems to the mountain Fynbos ecosystems of Table Mountain National Park.  This existing set of sites and studies offers a remarkable opportunity to not only examine N cycling across a range of settings, but also to better understand the interaction between the N cycle and the cycling of other P and the micronutrients.  In this project we will specifically focus on the response of N fixation to variation in soil nutrient status and marine aerosol N input into Western Cape Ecosystems.  We expect to find increasing reliance on N fixation derived N in the Fynbos ecosystems compared to the coastal settings where marine aerosol inputs are higher.  However, the extraordinary diversity of geochemical settings in this area (and the corresponding variation in vegetation cover) suggests the possibility that micronutrient and P availability may interact with, and potentially control, the biological fixation of N to these ecosystems.  The combination of the proposed N studies and the ongoing geochemical and floristic opportunities offer a unique opportunity to examine the interactions between the major biogeochemical cycles and the role that these interactions play in structural biological communities.

PI: Nichole Barger, University of Colorado

Co-PI: Mark Miller, US Geological Survey Southwest Biological Science Center, Kanab, UT

Co-PI: Jeff Herrick, USDA ARS. Las Cruces, NM

Funding Source: USDA Cooperative State Research Extension and Education Services (CSREES)-Managed Ecosystems program

Time Period: 6/1/08-5/31/2012       

The focus of this integrated research program is the development of approaches and tools for restoration and long-term sustainable management of pinyon-juniper (P-J) ecosystems that are based on principles of adaptive ecosystem management. Our research objectives are 1) to identify the P-J treatment strategies that are most effective in overcoming constraints to understory restoration and 2) evaluate the impacts of P-J treatment strategies on  important ecosystem attributes and functions. By understanding the important constraints to restoring understory vegetation and the potential risks associated with different treatment strategies, we expect that the long-term outcome of this research will be more effective restoration of understory vegetation communities in combination with improved ecosystem conditions. Building on the research program, our extension objectives are 1) to use the results of our research to develop a series of science-based decision making models and 2) to provide training to land managers and other stakeholders in using these models to plan and implement future projects. Training land managers to use science-based decision making models that are grounded in fundamental principles of ecology should lead to increased awareness of ecological processes and how these processes function across managed landscapes.  Following this, application of such models to managing P-J woodlands should lead to more scientifically defensible management plans and protection from litigation, which is always a management concern when working with a range of stakeholders that differ in how they believe these landscapes should be managed. Our educational objectives are to provide both classroom and field-based training to undergraduate and graduate students in methods of adaptive ecosystem management. This will be accomplished by developing an Ecosystem Management course for undergraduates, directing a summer undergraduate research and management internship program and training graduate students to direct their research to address the needs of land management goals. Our goal in providing these educational opportunities to students is to forge stronger ties between future ecologists and land managers with the outcome of bridging the knowledge gap between academic science and applied management issues.

PI: Greg Asner, Department of Global Ecology, Carnegie Institution of Washington, Stanford University

Co-PI: Jason Neff, Department of Geological Sciences and Environmental Studies, University of Colorado

Co-PI: Nichole Barger, University of Colorado Funding Source: NASA North American Carbon Program

Time Period: 2/2004-5/2008         

Arid and semi-arid ecosystems cover about 3.4 million square kilometers of North America.  The spatial patterns and abundance of herbaceous and woody plants throughout these regions are determined by bio-climatic conditions, topography, soil properties, and disturbance regimes.  During the past century, the balance between woody and herbaceous plants has shifted in many U.S. dryland ecosystems to favor trees and shrubs.  Recent syntheses suggest that woody plant encroachment contributes significantly to a North American carbon sink.  However, current estimates of gross or net rates of woody cover change in the western U.S. are crude and have not been linked to changes in C storage, thus the potential contribution of woody encroachment to the U.S. carbon budget remains elusive.         While our regional knowledge of current woody cover distributions, woody vegetation changes over time, and ecosystem C responses is very crude, what we do know has largely come from studies in “lowland” arid and semi-arid regions.  Pinyon-juniper (P-J) woodlands are among the least understood systems in terms of woody encroachment and thickening.  We do not know: (1) the current distribution, cover and carbon stocks of P-J ecosystems in a ~ 500,000 km2 portion of the Southwest; (2) regional rates of P-J cover and carbon change in relation to soils and grazing history; (3) soil organic carbon responses to changes in P-J cover; and (4) how to model current and future distributions of carbon stores in the P-J region.The broad goal of this project is to quantify and understand regional effects woody encroachment on carbon storage in pinyon-juniper ecosystems of the Southwest U.S.  We will quantify the contribution of woody encroachment in these systems to a proposed U.S. carbon sink and the interaction of aboveground changes in carbon with direct grazing impacts on soil carbon.  We will combine multi-platform remote sensing, field biogeochemical and dendrochronology studies, and spatio-temporal