John Bradford is a Research Ecologist with the USGS Southwest Biological 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
Climate Adaptation Strategies for Arid Grasslands
Developing a Decision Support Framework for Prioritizing Pinyon Juniper Forest Treatments on the Colorado Plateau
Modernizing sensor data workflows to leverage Internet of Things (IoT) and cloud-based technologies
Contributions to the development of the Western Association of Fish and Wildlife Agencies Sagebrush Conservation Strategy
Ecological Forecasting Workshop
Learning From the Past and Planning for the Future: Experience-Driven Insight Into Managing for Ecosystem Transformations Induced by Drought and Wildfire
Determining Successful Management and Restoration Strategies for Pinyon-Juniper Communities in the Face of Changing Climate and Wildfire
Can Management Actions Support Forest Regeneration Across the Diverse Landscapes and Climate Change Futures of the Southwestern U.S.?
Informing Seed Transfer Guidelines and Native Plant Materials Development: Research Supporting Restoration Across the Colorado Plateau and Beyond
Integrating short-term climate forecast into a restoration management support tool
Webinar: Forest Management for Mitigating Drought Impacts
An Interactive Web-Based Tool for Anticipating Long-term Drought Risk
Bioclimatic suitability for 11 dominant Colorado Plateau perennial grass species (ver. 2.0, November 2022)
Biome-wide sagebrush core habitat and growth areas estimated from a threat-based conservation design
Pinyon-juniper basal area, climate and demographics data from National Forest Inventory plots and projected under future density and climate conditions
Historical and future ecological drought conditions for rangelands of the western U.S.
High-resolution maps of historical and 21st century soil temperature and moisture data using multivariate matching algorithms for drylands of western U.S. and Canada
High-resolution maps of projected big sagebrush plant community biomass for 52 future climate scenarios using multivariate matching algorithms
High-resolution maps of historical and 21st century ecological drought metrics using multivariate matching algorithms for drylands of western U.S. and Canada
Climate and drought adaptation: historical and projected future exposure metrics for Southeastern Utah Group National Parks
Estimated tree mortality, basal area, climate, and drought conditions for ponderosa pine in forest inventory plots across the western U.S.
High-resolution maps of big sagebrush plant community biomass using multivariate matching algorithms
A snapshot of stakeholder science needs related to drought in the Colorado River Basin
Simulated rangewide big sagebrush regeneration estimates and relationships with abiotic variables as function of soils under historical and future climate projections
Ecologically relevant moisture and temperature metrics for assessing dryland ecosystem dynamics
Geologic, geomorphic, and edaphic underpinnings of dryland ecosystems: Colorado Plateau landscapes in a changing world
Dry forest decline is driven by both declining recruitment and increasing mortality in response to warm, dry conditions
A sagebrush conservation design to proactively restore America’s sagebrush biome
Primary production responses to extreme changes in North American Monsoon precipitation vary by elevation and plant functional composition through time
Management and environmental factors associated with simulated restoration seeding barriers in sagebrush steppe
Supporting the development and use of native plant materials for restoration on the Colorado Plateau (Fiscal Year 2021 Report)
Landscape-scale forest restoration decreases vulnerability to drought mortality under climate change in southwest USA ponderosa forest
Winter 2020-2021 edition
Soil moisture response to seasonal drought conditions and post-thinning forest structure
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?
Colorado River Basin Projects
The Colorado River Basin Actionable and Strategic Integrated Science and Technology Team has created an interactive map of USGS projects to highlight the integrated science currently conducted within the Colorado River Basin. These projects are not all inclusive of the work conducted by the USGS within the CRB, but highlight the broad range of integrated science currently conducted.
Science and Products
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Filter Total Items: 26
Climate Adaptation Strategies for Arid Grasslands
Helping National Parks in the 4-Corners region manage grasslands in a changing climate.Developing a Decision Support Framework for Prioritizing Pinyon Juniper Forest Treatments on the Colorado Plateau
Across the western U.S., pinyon and juniper trees are expanding into sagebrush and grassland plant communities. This vegetation change has been perceived to have a significant impact on the economic value of these grasslands, which support activities such as livestock grazing and hunting, but expanding pinyon and juniper forests may also lead to increased risk of fire. Over the past several decadeModernizing sensor data workflows to leverage Internet of Things (IoT) and cloud-based technologies
Drought is a major problem in the American Southwest that is expected to worsen under the effects of climate change. Currently, the Southwest Biological Science Center is monitoring the effects of drought with soil moisture probes in a range of ecosystems across an elevational gradient on the Colorado Plateau. These data are used in multiple studies to analyze the effects of drought on vegetationContributions to the development of the Western Association of Fish and Wildlife Agencies Sagebrush Conservation Strategy
USGS scientists are contributing to the development of the Western Association of Fish and Wildlife Agencies Sagebrush Conservation Strategy, a strategy intended to provide guidance so that efforts to conserve the iconic greater sage-grouse can be expanded to the entire sagebrush biome to benefit the people and wildlife that depend on it.Ecological Forecasting Workshop
Natural resource managers are coping with rapid changes in both environmental conditions and ecosystems. Enabled by recent advances in data collection and assimilation, short-term ecological forecasting may be a powerful tool to help resource managers anticipate impending changes in ecosystem dynamics (that is, the approaching near-term changes in ecosystems). Managers may use the information in fLearning From the Past and Planning for the Future: Experience-Driven Insight Into Managing for Ecosystem Transformations Induced by Drought and Wildfire
Drought and wildfire pose enormous threats to the integrity of natural resources that land managers are charged with protecting. Recent observations and modeling forecasts indicate that these stressors will likely produce catastrophic ecosystem transformations, or abrupt changes in the condition of plants, wildlife, and their habitats, in regions across the country in coming decades. In this pDetermining Successful Management and Restoration Strategies for Pinyon-Juniper Communities in the Face of Changing Climate and Wildfire
Pinyon-juniper woodlands are important ecosystems in the western U.S. that provide numerous critical environmental, economic, and cultural benefits. For example, pinyon pines are a significant cultural resource for multiple Native American Tribes and provide necessary habitat for plants and wildlife (including at risk species, such as the pinyon-jay). Despite their importance, stress put on pinyonCan Management Actions Support Forest Regeneration Across the Diverse Landscapes and Climate Change Futures of the Southwestern U.S.?
Ponderosa pine forests are declining and their future persistence is uncertain. Most research on forest declines has focused on the effects of disturbances including wildfire, insect outbreaks, and severe drought on mortality of mature trees. Yet, recent research suggests that ponderosa pine declines may be even more severe as these ecosystems fail to regenerate naturally (i.e. grow from seed to aInforming Seed Transfer Guidelines and Native Plant Materials Development: Research Supporting Restoration Across the Colorado Plateau and Beyond
As restoration needs for natural landscapes grow due to higher frequency and/or intensity disturbances, pressure from invasive species, and impacts resulting from changing climates, considerable time and resources are being invested to guide the development and deployment of native plant materials (NPMs). Across lower elevations of the Colorado Plateau, a region composed primarily of public land...Integrating short-term climate forecast into a restoration management support tool
Natural resources managers are regularly required to make decisions regarding upcoming restoration treatments, often based on little more than business as usual practices. To assist in the decision-making process, we created a tool that predicts site-specific soil moisture and climate for the upcoming year, and provides guidance on whether common restoration activities (i.e. seeding, planting) wilWebinar: Forest Management for Mitigating Drought Impacts
View this webinar to learn more about forest drought in the Southwest U.S. and ongoing research to mitigate regional drought effects.An Interactive Web-Based Tool for Anticipating Long-term Drought Risk
Droughts are becoming more frequent and severe and this trend is expected to continue in the coming century. Drought effects on natural resources include reduced water availability for plants and humans, as well as increased insect, disease, and vegetation mortality. Land managers need more information regarding how water availability may change and how drought will affect their sites in the futur - Data
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Bioclimatic suitability for 11 dominant Colorado Plateau perennial grass species (ver. 2.0, November 2022)
These data were compiled to represent the distribution of environmental conditions with recognized importance to perennial grasses in dryland areas of the western U.S. Objective(s) of our study were to … evaluate how those environmental drivers are related to perennial grass distributions and use the results to assess how perennial grass distributions may shift in response to future climate changeBiome-wide sagebrush core habitat and growth areas estimated from a threat-based conservation design
These data were compiled as a part of a landscape conservation design effort for the sagebrush biome, and are the result of applying a spatially explicit model that assessed geographic patterns in sagebrush ecological integrity and used these results to identify Core Sagebrush Areas (CSAs), Growth Opportunity Areas (GOAs), and Other Rangeland Areas (ORAs). Our overall objective in this study was tPinyon-juniper basal area, climate and demographics data from National Forest Inventory plots and projected under future density and climate conditions
These data were compiled to help understand how climate change may impact dryland pinyon-juniper ecosystems in coming decades, and how resource management might be able to minimize those impacts. Objective(s) of our study were to model the demographic rates of PJ woodlands to estimate the areas that may decline in the future vs. those that will be stable. We quantified populations growth rates acrHistorical and future ecological drought conditions for rangelands of the western U.S.
These NetCDF data were compiled to investigate how rangelands in the western U.S. are limited by access to water. As a result, these ecosystems may be especially vulnerable to changes in water availability and drought as a result of climate change. This project utilized an ecosystem water balance model to quantify spatial and temporal patterns of rangeland ecological drought conditions under histoHigh-resolution maps of historical and 21st century soil temperature and moisture data using multivariate matching algorithms for drylands of western U.S. and Canada
These data were compiled as a supplement to a previously published journal article (Bradford et al., 2019), that employed a ecosystem water balance model to characterize current and future patterns in soil temperature and moisture conditions in dryland areas of western North America. Also, these data are associated with a published USGS data release (Bradford and Schlaepfer, 2019). The objectivesHigh-resolution maps of projected big sagebrush plant community biomass for 52 future climate scenarios using multivariate matching algorithms
These data were compiled for the study: Divergent climate change effects on widespread dryland plant communities driven by climatic and ecohydrological gradients. The objectives of our study were to (1) describe how climate change will alter the biomass and composition of key plant functional types; (2) quantify the impacts of climate change on future functional type biomass and composition alongHigh-resolution maps of historical and 21st century ecological drought metrics using multivariate matching algorithms for drylands of western U.S. and Canada
These data were compiled using a new multivariate matching algorithm that transfers simulated soil moisture conditions (Bradford et al. 2020) from an original 10-km resolution to a 30-arcsec spatial resolution. Also, these data are a supplement to a previously published journal article (Bradford et al., 2020) and USGS data release (Bradford and Schlaepfer, 2020). The objectives of our study were tClimate and drought adaptation: historical and projected future exposure metrics for Southeastern Utah Group National Parks
These data were compiled to evaluate the magnitude and direction of change from historical conditions in climate metrics across the Southeastern Utah Group (SEUG) of National Parks. Objective(s) of our study were to quantify the magnitude and direction of change from historical conditions in climate metrics across SEUG parks at a meaningful scale for land managers and practitioners. These data repEstimated tree mortality, basal area, climate, and drought conditions for ponderosa pine in forest inventory plots across the western U.S.
These data consist of environmental covariates and estimated plot-level mortality of ponderosa pine trees. Environmental covariates include growing season temperature and soil moisture, and values are summarized into long-term mean conditions, and anomalies observed between forest inventory sampling events for each plot. Data also include plot locations (with uncertainty introduced by the US ForesHigh-resolution maps of big sagebrush plant community biomass using multivariate matching algorithms
These GeoTIFF data were compiled to investigate how a new multivariate matching algorithm transfers simulated plant functional biomass of big sagebrush plant communities from 200 sites to a gridded product with 30-arcsec spatial resolution. Objectives of our study were to (1) describe how climate change will alter the biomass and composition of key plant functional types; (2) quantify the impactsA snapshot of stakeholder science needs related to drought in the Colorado River Basin
Stakeholder science needs were determined by reviewing more than 200 recently published literature items and web pages from Colorado River Basin (CRB) stakeholders. These stakeholder communications were used to characterize over 400 stakeholder science needs by reviewing their priorities, strategies, issues, missions, and concerns related to drought in the CRB. Members of the CRB Integrated SciencByArizona Water Science Center, California Water Science Center, Colorado Water Science Center, Fort Collins Science Center, Geology, Geophysics, and Geochemistry Science Center, Nevada Water Science Center, New Mexico Water Science Center, Southwest Biological Science Center, Utah Water Science Center, Wyoming-Montana Water Science CenterSimulated rangewide big sagebrush regeneration estimates and relationships with abiotic variables as function of soils under historical and future climate projections
These NetCDF data were compiled to investigate how two complementary models can contribute to our understanding of contemporary and future big sagebrush regeneration across the historical and potential future sagebrush region. Objective of our study was to apply both models to address three specific objectives: (i) examine the geographic patterns of big sagebrush regeneration probabilities that th - Multimedia
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Ecologically relevant moisture and temperature metrics for assessing dryland ecosystem dynamics
In drylands, water-limited regions that cover ~40% of the global land surface, ecosystems are primarily controlled by access to soil moisture and exposure to simultaneously hot and dry conditions. Quantifying ecologically relevant environmental metrics is difficult in drylands because the response of vegetation to moisture and temperature conditions is not easily explained solely by climate-basedGeologic, geomorphic, and edaphic underpinnings of dryland ecosystems: Colorado Plateau landscapes in a changing world
Drylands represent more than 41% of the global land surface and are at degradation risk due to land use and climate change. Developing strategies to mitigate degradation and restore drylands in the face of these threats requires an understanding of how drylands are shaped by not only soils and climate, but also geology and geomorphology. However, few studies have completed such a comprehensive anaDry forest decline is driven by both declining recruitment and increasing mortality in response to warm, dry conditions
Aim: Anticipating when and where changes in species' demographic rates will lead to range shifts in response to changing climate remains a major challenge. Despite evidence of increasing mortality in dry forests across the globe in response to drought and warming temperatures, the overall impacts on the distribution of dry forests are largely unknown because we lack comparable large-scale data onA sagebrush conservation design to proactively restore America’s sagebrush biome
A working group of experts with diverse professional backgrounds and disciplinary expertise was assembled to conceptualize a spatially explicit conservation design to support and inform the Sagebrush Conservation Strategy Part 2. The goal was to leverage recent advancements in remotely sensed landcover products to develop spatially and temporally explicit maps of sagebrush rangeland condition andByPrimary production responses to extreme changes in North American Monsoon precipitation vary by elevation and plant functional composition through time
Primary production in dryland ecosystems is limited by water availability and projected to be strongly affected by future shifts in seasonal precipitation. Warm-season precipitation derived from the North American Monsoon contributes 40% of annual precipitation to dryland ecosystems in the southwestern U.S. and is projected to become more variable. However, there is large uncertainty on whether thManagement and environmental factors associated with simulated restoration seeding barriers in sagebrush steppe
Adverse weather conditions, particularly freezing or drought, are often associated with poor seedling establishment following restoration seeding in drylands like the Great Basin sagebrush steppe (USA). Management decisions such as planting date or seed source could improve restoration outcomes by reducing seedling exposure to weather barriers. We simulated the effects of management and environmenSupporting the development and use of native plant materials for restoration on the Colorado Plateau (Fiscal Year 2021 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 providLandscape-scale forest restoration decreases vulnerability to drought mortality under climate change in southwest USA ponderosa forest
Drought-induced tree mortality is predicted to increase in dry forests across the western USA as future projections show hotter, drier climates potentially resulting in large-scale tree die-offs, changes in species composition, and loss of forest ecosystem services, including carbon storage. While some studies have found that forest stands with greater basal areas (BA) have higher drought mortalitWinter 2020-2021 edition
In this edition: 2021 year in review, native seed development process, RestoreNet protocol published and lots of associated research, a handful of climate change science, and more.Soil moisture response to seasonal drought conditions and post-thinning forest structure
Prolonged drought conditions in semi-arid forests can lead to widespread vegetation stress and mortality. However, the distribution of these effects is not spatially uniform. We measured soil water potential at high spatial and temporal resolution using 112 sensors distributed across a ponderosa pine forest in northern Arizona, USA, during two abnormally dry years with below-average total precipitThe 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 componentsAre 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, the - Web Tools
Colorado River Basin Projects
The Colorado River Basin Actionable and Strategic Integrated Science and Technology Team has created an interactive map of USGS projects to highlight the integrated science currently conducted within the Colorado River Basin. These projects are not all inclusive of the work conducted by the USGS within the CRB, but highlight the broad range of integrated science currently conducted.
- News