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
Rapid broad-scale ecosystem changes and their consequences for biodiversity
Transient population dynamics impede restoration and may promote ecosystem transformation after disturbance
Effects of a changing climate on the hydrological cycle in cold desert ecosystems of the Great Basin and Columbia Plateau
Assessing rangeland health under climate variability and change
Long‐term plant community trajectories suggest divergent responses of native and non‐native perennials and annuals to vegetation removal and seeding treatments
Patterns of big sagebrush plant community composition and stand structure in the western United States
Increasing temperature seasonality may overwhelm shifts in soil moisture to favor shrub grass dominance in Colorado Plateau drylands
Estimating soil respiration in a subalpine landscape using point, terrain, climate and greenness data
Bioclimatic envelopes for individual demographic events driven by extremes: Plant mortality from drought and warming
Influence of climate, post‐treatment weather extremes, and soil factors on vegetation recovery after restoration treatments in the southwestern US
Adapting management to a changing world: Warm temperatures, dry soil, and interannual variability limit restoration success of a dominant woody shrub in temperate drylands
Plant production responses to precipitation differ along an elevation gradient and are enhanced under extremes
Science and Products
- Publications
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Rapid broad-scale ecosystem changes and their consequences for biodiversity
Biodiversity contributes to and depends on ecosystem structure and associated function. Ecosystem structure, such as the amount and type of tree cover, influences fundamental abiotic variables such as near-ground incoming solar radiation (e.g., Royer et al. 2011), which in turn affects species and associated biodiversity (e.g., Trotter et al. 2008). In many systems, foundational, dominant, or keysAuthorsDavid D. Breshears, Jason P. Field, Darin J. Law, Juan C. Villegas, Craig D. Allen, Neil S. Cobb, John B. BradfordTransient population dynamics impede restoration and may promote ecosystem transformation after disturbance
The apparent failure of ecosystems to recover from increasingly widespread disturbance is a global concern. Despite growing focus on factors inhibiting resilience and restoration, we still know very little about how demographic and population processes influence recovery. Using inverse and forward demographic modelling of 531 post‐fire sagebrush populations across the western US, we show that demoAuthorsRobert K. Shriver, Caitlin M. Andrews, Robert Arkle, David Barnard, Michael C. Duniway, Matthew J. Germino, David S. Pilliod, David A. Pyke, Justin L. Welty, John B. BradfordEffects of a changing climate on the hydrological cycle in cold desert ecosystems of the Great Basin and Columbia Plateau
Climate change is already resulting in changes in cold desert ecosystems, lending urgency to the need to understand climate change effects and develop effective adaptation strategies. In this review, we synthesize information on changes in climate and hydrologic processes during the last century for the Great Basin and Columbia Plateau, and discuss future projections for the 21st century. We deveAuthorsKeirith A. Snyder, Louisa B. Evers, Jeanne C. Chambers, Jason B. Dunham, John B. Bradford, Michael E. LoikAssessing rangeland health under climate variability and change
RANGELAND HEALTH IN A CHANGING WORLD Rangeland health is an integrated metric that describes a complex suite of ecosystem properties and processes as applied to resource management. While the concept of “healthy” landscapes has a long history, the term “rangeland health” was codified in the US in 1994 as part of an effort to move towards a national, data driven, rangeland condition assessment (NatAuthorsJohn B. Bradford, Michael C. Duniway, Seth M. MunsonLong‐term plant community trajectories suggest divergent responses of native and non‐native perennials and annuals to vegetation removal and seeding treatments
Land managers frequently apply vegetation removal and seeding treatments to restore ecosystem function following woody plant encroachment, invasive species spread, and wildfire. However, the long‐term outcome of these treatments is unclear due to a lack of widespread monitoring. We quantified how vegetation removal (via wildfire or management) with or without seeding and environmental conditions rAuthorsStella M. Copeland, Seth M. Munson, John B. Bradford, Bradley J. Butterfield, Kevin L. GunnellPatterns of big sagebrush plant community composition and stand structure in the western United States
Big sagebrush (Artemisia tridentata Nutt.) plant communities are found in western North America and comprise a mix of shrubs, forbs, and grasses. Climate, topography, and soil water availability are important factors that shape big sagebrush stand structure and plant community composition; however, most studies have focused on understanding these relationships at sites in a small portion of the biAuthorsVictoria E. Pennington, John B. Bradford, Kyle A. Palmquist, Rachel R. Renne, William K. LauenrothIncreasing temperature seasonality may overwhelm shifts in soil moisture to favor shrub grass dominance in Colorado Plateau drylands
Ecosystems in the southwestern U.S. are hotspots for climate change, and are predicted to experience continued warming and drying. In these water-limited systems, the balance between herbaceous and woody plant abundance impacts biodiversity and ecosystem processes, highlighting the need to understand how climate change will influence functional composition. However, variability in topo-edaphic coAuthorsJennifer R. Gremer, Caitlin M. Andrews, Jodi R. Norris, Lisa P. Thomas, Seth M. Munson, Michael C. Duniway, John B. BradfordEstimating soil respiration in a subalpine landscape using point, terrain, climate and greenness data
Landscape carbon (C) flux estimates are necessary for assessing the ability of terrestrial ecosystems to buffer further increases in anthropogenic carbon dioxide (CO2) emissions. Advances in remote sensing have allowed for coarse-scale estimates of gross primary productivity (GPP) (e.g., MODIS 17), yet efforts to assess spatial patterns in respiration lag behind those of GPP. Here, we demonstrateAuthorsErin Michele Berryman, Melanie K. Vanderhoof, John B. Bradford, Todd Hawbaker, Paul D. Henne, Sean P. Burns, John M. Frank, Richard A. Birdsey, Michael G. RyanBioclimatic envelopes for individual demographic events driven by extremes: Plant mortality from drought and warming
The occurrence of plant species across the globe is largely constrained by climate. Ecologists use plant-climate relationships such as bioclimatic envelopes and related niche models to determine potential environmental conditions promoting probable species occurrence. Traditionally bioclimatic envelopes either exclude disturbance explicitly, or only include disturbance as infrequent and smaller scAuthorsDarin J. Law, Henry D. Adams, David D. Breshears, Neil S. Cobb, John B. Bradford, Chris B. Zou, Jason P. Field, Alfonso A. Gardea, A. Park Williams, Travis E. HuxmanInfluence of climate, post‐treatment weather extremes, and soil factors on vegetation recovery after restoration treatments in the southwestern US
AimsUnderstanding the conditions associated with dryland vegetation recovery after restoration treatments is challenging due to a lack of monitoring data and high environmental variability over time and space. Tracking recovery trajectories with satellite‐based vegetation indices can strengthen predictions of restoration outcomes across broad areas with varying environmental conditions.LocationSouAuthorsStella M. Copeland, Seth M. Munson, John B. Bradford, Bradley J. ButterfieldAdapting management to a changing world: Warm temperatures, dry soil, and interannual variability limit restoration success of a dominant woody shrub in temperate drylands
Restoration and rehabilitation of native vegetation in dryland ecosystems, which encompass over 40% of terrestrial ecosystems, is a common challenge that continues to grow as wildfire and biological invasions transform dryland plant communities. The difficulty in part stems from low and variable precipitation, combined with limited understanding about how weather conditions influence restoration oAuthorsRobert K. Shriver, Caitlin M. Andrews, David S. Pilliod, Robert Arkle, Justin L. Welty, Matthew J. Germino, Michael C. Duniway, David A. Pyke, John B. BradfordPlant production responses to precipitation differ along an elevation gradient and are enhanced under extremes
The sensitivity of plant production to precipitation underlies the functioning of ecosystems. Studies that relate long-term mean annual precipitation and production across multiple sites(spatial relationship) or examine interannual linkages within a site (temporal relationship) can reveal biophysical controls over ecosystem function but have limited ability to infer responses to extreme changes inAuthorsSeth M. Munson, Erin L. Bunting, John B. Bradford, Bradley J. Butterfield, Jennifer R. Gremer - Science
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