USGS - science for a changing world


John B Bradford

Research Ecologist

Colorado Plateau Field Station, SBSC

Office Phone: 928-523-7766
Fax: 928-556-9111

Colorado Plateau Research Station
P.O. Box 5614, Northern Arizona University, Mail Stop 9394
Flagstaff , AZ 86011-5614

Supervisor: Kathryn A Thomas
Protecting the nation’s natural and cultural resources and landscapes is essential to sustaining our quality of life and economy. Native fish and wildlife species depend on healthy rivers, streams, wetlands, forests, grasslands and coastal areas in order to thrive. Managing these natural and cultural resources and landscapes, however, has become increasingly complex. Land use changes and impacts such as drought, wildfire, habitat fragmentation, contaminants, pollution, invasive species, disease and a rapidly changing climate can threaten human populations as well as native species and their habitats. Landscape Conservation Cooperatives (LCCs) are public-private partnerships that recognize these challenges transcend...
Explore climate change impacts on vegetation across the Desert and Southern Rockies LCCs using historical monitoring data collected from 23 sites across the Sonoran, Chihuahuan, Mojave and Colorado Plateau deserts for 30-50 years. This data will then be combined with ecosystem water balance model simulations to establish features of water availability critical for plant species response. Results will allow managers to identify species and communities at risk under future climate scenarios based on predicted changes in plant water availability. Due to the high variability in soils, incorporating a detailed understanding of soil water availability beyond bioclimatic envelope approaches in the desert Southwest is essential...
Categories: Project; Types: Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service; Tags: Decision Support, California, New Mexico, climate change, desert southwest, All tags...
The future of sage grouse depends on the future of sagebrush, we have limited ability to anticipate impacts of climate change on sagebrush populations. Current efforts to forecast sagebrush habitat typically rely on species distribution models (SDMs), which suffer from a variety of well-known weaknesses. However, by integrating SDMs with complementary research approaches, such as historical data analysis and mechanistic models, we can provide increased confidence in projections of habitat change. Our goal is to forecast the effect of climate change on the distribution and abundance of big sagebrush in order to inform conservation planning, and sage grouse management in particular, across the Intermountain West....
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 their resistance to drought) and maximize the ability of forests to recover after a drought (i.e. improve their resilience). Evidence suggests that forests with certain combinations of tree species, sizes, and stem densities are better able to withstand and recover from drought. The goal of this study is to identify which forest...
Abstract (from Increasing aridity as a result of climate change is expected to exacerbate tree mortality. Reducing forest basal area – the cross-sectional area of tree stems within a given ground area – can decrease tree competition, which may reduce drought-induced tree mortality. However, neither the magnitude of expected mortality increases, nor the potential effectiveness of basal area reduction, has been quantified in dryland forests such as those of the drought-prone Southwest US. We used thousands of repeatedly measured forest plots to show that unusually warm and dry conditions are related to high tree mortality rates and that mortality is positively...
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