John B Bradford, Ph.D.
John Bradford is a Research Ecologist with the USGS Northwest Climate Adaptation Science Center. John studies dryland ecosystems in the context of global change and works with resource managers to identify adaptive strategies for sustaining these ecosystems in a changing world.
John focuses on understanding how changing climate, disturbances, and land use influence dryland vegetation, plant communities, and ecosystem services. He is currently engaged in the broad topics of ecohydrology and dryland sustainability in the western U.S. and has projects examining a) the potential influence of changing climatic conditions on the distribution and regeneration potential of trees and shrubs in the intermountain western U.S., b) strategies for understanding and enhancing dryland ecosystem resilience to changing climate and drought patterns, and c) ecosystem water balance and patterns of plant-available soil water in dryland regions.
Professional Experience
2011- Present: Research Ecologist - US Geological Survey, Southwest Biological Science Center, Flagstaff, AZ
2006 - 2011: Research Ecologist - USDA Forest Service, North Central Research Station, Grand Rapids, MN
2004 - 2006: Research Ecologist (Postdoctoral) - USDA Forest Service, Rocky Mountain Research Station, Fort Collins, CO
Education and Certifications
2004 - Ph.D., Ecology, Colorado State University
1996 - B.A., Biology, Cornell University
Science and Products
The aboveground and belowground growth characteristics of juvenile conifers in the southwestern United States
Are drought indices and climate data good indicators of ecologically relevant soil moisture dynamics in drylands?
Tree mortality response to drought-density interactions suggests opportunities to enhance drought resistance
Making research relevant: Sharing climate change research with rangeland advisors to transform results into drought resilience
Understanding the future of big sagebrush regeneration: challenges of projecting complex ecological processes
Divergent climate change effects on widespread dryland plant communities driven by climatic and ecohydrological gradients
U.S. Geological Survey landscape science strategy 2020–2030
Biotic vs abiotic controls on temporal sensitivity of primary production to precipitation across North American drylands
Quantifying the demographic vulnerabilities of dry woodlands to climate and competition using rangewide monitoring data
Species mixture effects and climate influence growth, recruitment and mortality in Interior West USA Populus tremuloides-conifer communities
Supporting the development and use of native plant materials for restoration on the Colorado Plateau (Fiscal Year 2020 Report)
UAV-based estimate of snow cover dynamics: Optimizing semi-arid forest structure for snow persistence
RAMPS: Restoration Assessment & Monitoring Program for the Southwest
Big Sagebrush Ecosystem Response to Climate & Disturbance
Assessing the Vulnerability of Dryland Ecosystems to Drought in the Western U.S.
Forecasting Future Changes in Sagebrush Distribution and Abundance
Informing and Evaluating Forest Management Strategies to Promote Drought Resistance
Climate change and ecohydrology in temperate dryland ecosystems: a global assessment
Simulated Soil Water Potential in National Parks and Monuments of the Southern Colorado Plateau, 1915-2099 - Data
Long-term Experimental Forest Growth and Drought Data
Potential Land-use Intensity, Aridification Trends, Overlap, and Impact Scenarios, Geospatial Data, Colorado Plateau, USA
Global temperate drylands climate change vulnerability
Science and Products
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The aboveground and belowground growth characteristics of juvenile conifers in the southwestern United States
Juvenile tree survival will play an important role in the persistence of coniferous forests and woodlands in the southwestern United States (SWUS). Vulnerability to climatic and environmental stress declines as trees grow, such that larger, more deeply rooted juveniles are less likely to experience mortality. It is unclear how juvenile conifers partition the aboveground and belowground componentsAuthorsN.L. Pirtel, R.M. Hubbard, John B. Bradford, T.E. Kolb, M.E. Litvak, S.R. Abella, S.M. Porter, Petrie M.D.Are drought indices and climate data good indicators of ecologically relevant soil moisture dynamics in drylands?
Droughts are disproportionately impacting global dryland regions where ecosystem health and function are tightly coupled to moisture availability. Drought severity is commonly estimated using algorithms such as the standardized precipitation-evapotranspiration index (SPEI), which can estimate climatic water balance impacts at various hydrologic scales by varying computational length. However, theAuthorsDavid Barnard, Matthew Germino, John B. Bradford, Rory O'Connor, Caitlin M. Andrews, Robert K ShriverTree mortality response to drought-density interactions suggests opportunities to enhance drought resistance
The future of dry forests around the world is uncertain given predictions that rising temperatures and enhanced aridity will increase drought-induced tree mortality. Using forest management and ecological restoration to reduce density and competition for water offers one of the few pathways that forests managers can potentially minimize drought-induced tree mortality. Competition for water duringAuthorsJohn B. Bradford, Robert K Shriver, Marcos D. Robles, Lisa A McCauley, Caitlin M. Andrews, Michael A. Crimmins, David M. BellMaking research relevant: Sharing climate change research with rangeland advisors to transform results into drought resilience
On the Ground• Public programs, strategies, and incentives to implement rangeland climate adaptation are more effective if they are tailored to local drought exposures, sensitivities, and adaptation opportunities. As such, local rangeland advisers who aid in climate adaptation are pivotal to the development of these resources.• We hosted a virtual workshop with rangeland advisors to share resultsAuthorsMaude Dinan, Peter B. Adler, John B. Bradford, Mark Brunson, Emile Elias, Andrew J Felton, Christina Greene, Jeremy J. James, Katharine Suding, Eric ThackerUnderstanding the future of big sagebrush regeneration: challenges of projecting complex ecological processes
Regeneration is an essential demographic step that affects plant population persistence, recovery after disturbances, and potential migration to track suitable climate conditions. Challenges of restoring big sagebrush (Artemisia tridentata) after disturbances including fire-invasive annual grass interactions exemplify the need to understand the complex regeneration processes of this long-lived, woAuthorsDaniel Rodolphe Schlaepfer, John B. Bradford, William K. Lauenroth, Robert K ShriverDivergent climate change effects on widespread dryland plant communities driven by climatic and ecohydrological gradients
Plant community response to climate change will be influenced by individual plant responses that emerge from competition for limiting resources that fluctuate through time and vary across space. Projecting these responses requires an approach that integrates environmental conditions and species interactions that result from future climatic variability. Dryland plant communities are being substantiAuthorsKyle A. Palmquist, Daniel Rodolphe Schlaepfer, Rachel R. Renne, Steve Torbit, Kevin Doherty, Thomas E. Remington, Greg Watson, John B. Bradford, William K. LauenrothU.S. Geological Survey landscape science strategy 2020–2030
Across our Nation, multiple Federal, State, Tribal, and local governments are working with stakeholders and landowners to restore, conserve, and manage lands and resources to benefit fish, wildlife, and people. One of the largest Federal efforts is led by the U.S. Department of the Interior (DOI), with multiple DOI agencies working to conserve and manage public lands, resources, and cultural heritAuthorsKaren E. Jenni, Sarah K. Carter, Nicholas G. Aumen, Zachary H. Bowen, John B. Bradford, Michael A. Chotkowski, Leslie Hsu, Peter S. Murdoch, Scott W. Phillips, Kevin L. Pope, Rudy Schuster, Melanie J. Steinkamp, Jake Weltzin, George Z. XianBiotic vs abiotic controls on temporal sensitivity of primary production to precipitation across North American drylands
Dryland net primary productivity (NPP) is sensitive to temporal variation in precipitation (PPT), but the magnitude of this ‘temporal sensitivity’ varies spatially. Hypotheses for spatial variation in temporal sensitivity have often emphasized abiotic factors, such as moisture limitation, while overlooking biotic factors, such as vegetation structure.We tested these hypotheses using spatiotemporalAuthorsAndrew J Felton, Robert K Shriver, John B. Bradford, Katharine N. Suding, Brady W Allred, Peter B. AdlerQuantifying the demographic vulnerabilities of dry woodlands to climate and competition using rangewide monitoring data
Climate change is expected to alter the distribution and abundance of tree species, impacting ecosystem structure and function. Yet, anticipating where this will occur is often hampered by a lack of understanding of how demographic rates, most notably recruitment, vary in response to climate and competition across a species range. Using large-scale monitoring data on two dry woodland tree speciesAuthorsRobert K Shriver, Charles Yackulic, David M. Bell, John B. BradfordSpecies mixture effects and climate influence growth, recruitment and mortality in Interior West USA Populus tremuloides-conifer communities
Tree-species mixture effects (e.g. complementarity and facilitation) have been found to increase individual-tree productivity, lessen mortality and improve recruitment in forests worldwide. By promoting more efficient and complete resource use, mixture effects may also lessen individual-tree-level water stress, thus improving drought resistance. We investigated the influence of mixture effects onAuthorsChristopher E. Looney, Wilfred J Previant, John B. Bradford, Linda M NagelSupporting the development and use of native plant materials for restoration on the Colorado Plateau (Fiscal Year 2020 Report)
A primary focus of the Colorado Plateau Native Plant Program (CPNPP) is to identify and develop appropriate native plant materials (NPMs) for current and future restoration projects. Multiple efforts have characterized the myriad challenges inherent in providing appropriate seed resources to enable effective, widespread restoration and have identified a broad suite of research activities to providAuthorsRobert Massatti, Daniel E. Winkler, Sasha C. Reed, Michael C. Duniway, Seth M. Munson, John B. BradfordUAV-based estimate of snow cover dynamics: Optimizing semi-arid forest structure for snow persistence
Seasonal snow cover in the dry forests of the American West provides essential water resources to both human and natural systems. The structure of trees and their arrangement across the landscape are important drivers of snow cover distribution across these forests, varying widely in both space and time. We used unmanned aerial vehicle (UAV) multispectral imagery and Structure-from-Motion (SfM) moAuthorsAdam Belmonte, Temuulen T. Sankey, Joel Biedermann, John B. Bradford, Scott J Goetz, Thomas Kolb - Science
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RAMPS: Restoration Assessment & Monitoring Program for the Southwest
The Restoration Assessment and Monitoring Program for the Southwest (RAMPS) seeks to assist U.S. Department of the Interior (DOI) and other land management agencies in developing successful techniques for improving land condition in dryland ecosystems of the southwestern United States. Invasion by non-native species, wildfire, drought, and other disturbances are growing rapidly in extent and...Big Sagebrush Ecosystem Response to Climate & Disturbance
Big sagebrush ecosystems are a major component of landscapes in the western U.S. and provide vital habitat to a wide array of wildlife species. However, big sagebrush ecosystems have been dramatically impacted by disturbances in the past several decades. This collaborative research between USGS and the University of Wyoming focuses on understanding how climatic and soil conditions influence big...Assessing the Vulnerability of Dryland Ecosystems to Drought in the Western U.S.
In the western U.S., rising temperatures and pronounced drought conditions pose significant challenges to public land managers. Widespread declines of multiple plant species have already been observed, providing insight into what the future could look like for vegetation in the region as conditions are projected to become warmer and drier. To understand how vulnerable western ecosystems are to droForecasting Future Changes in Sagebrush Distribution and Abundance
Covering 120 million acres across 14 western states and 3 Canadian provinces, sagebrush provides critical habitat for species such as pronghorn, mule deer, and sage-grouse – a species of conservation concern. The future of these and other species is closely tied to the future of sagebrush. Yet this important ecosystem has already been affected by fire, invasive species, land use conversion, and noInforming and Evaluating Forest Management Strategies to Promote Drought Resistance
Severe droughts cause widespread tree mortality and decreased growth in forests across the globe—even in areas with cooler climates. Mitigating the negative effects of climate change, in particular increased drought frequency and severity, poses a major challenge to forest managers. Managers are searching for strategies that minimize the negative effects of drought on forests (i.e. increase theirClimate change and ecohydrology in temperate dryland ecosystems: a global assessment
Water cycling and availability exert dominant control over ecological processes and the sustainability of ecosystem services in water - limited ecosystems. Consequently, dryland ecosystems have the potential to be dramatically impacted by hydrologic alterations emerging from global change, notably increasing temperature and altered precipitation patterns. In addition, the possibility of directly m - Data
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Simulated Soil Water Potential in National Parks and Monuments of the Southern Colorado Plateau, 1915-2099 - Data
These data were simulated using the SOILWAT model and were intended to characterize soil-water conditions at different ecological sites on the Southern Colorado Plateau. SOILWAT is a daily, site-specific, multi soil-layer, ecosystem water-balance model, driven by daily meteorology, as well as site soil texture and vegetation. The sites simulated correspond with Inventory and Monitoring (I&M) plotsLong-term Experimental Forest Growth and Drought Data
These data were compiled in order to represent long-term (multi-decadal) forest growth across eight different experimental forests in the United States, each with replicated levels of density treatments, as well as an important drought index correlated to growth. Forests around the world are experiencing severe droughts and elevated competitive intensity due to increased tree density. These data cPotential Land-use Intensity, Aridification Trends, Overlap, and Impact Scenarios, Geospatial Data, Colorado Plateau, USA
These geospatial data characterize the potential for geographic overlap among areas likely to experience climate drying (aridification) and high intensity land-use with population growth, recreation tourism, agriculture, energy development, and mining on the Colorado Plateau. Spatial overlap between areas of high land-use intensity and aridification were used to create scenarios and correspondingGlobal temperate drylands climate change vulnerability
Drylands cover 40% of the global terrestrial surface and provide important ecosystem services. While drylands as a whole are expected to increase in distribution and aridity in coming decades, temperature and precipitation forecasts vary by latitude and geographic region suggesting different trajectories for tropical, subtropical, and temperate drylands. Uncertainty in the future of tropical and s - Multimedia
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