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Miguel Villarreal

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Polygon locations of fire perimeters in the Sky Island mountain ranges in the Madrean Archipelago Ecoregion of the southwestern United States and northern Mexico. These fires occurred from 1985 to 2011 and were mapped using Landsat satellite imagery.
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To determine if invasive annual grasses increased around energy developments after the construction phase, we calculated an invasives index using Landsat TM and ETM+ imagery for a 34-year time period (1985-2018) and assessed trends for 1,755 wind turbines (from the U.S. Wind Turbine Database) installed between 1988 and 2013 in the southern California desert. The index uses the maximum normalized difference vegetation index (NDVI) for early season greenness (January-June), and mean NDVI (July-October) for the later dry season. We estimated the relative cover of invasive annuals each year at turbine locations and control sites and tested for changes before and after each turbine was installed. These data were used...
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Wildfire Probability Mapping Based on Regional Soil Moisture Models
Wildfires scorched 10 million acres across the United States in 2015, and for the first time on record, wildfire suppression costs topped $2 billion. Wildfire danger modeling is an important tool for understanding when and where wildfires will occur, and recent work by our team in the South Central United States has shown wildfire danger models may be improved by incorporating soil moisture information. Advancements in wildfire danger modeling may increase wildfire preparedness, and therefore decrease loss of life, property, and habitat due to wildfire. Still, soil moisture—an important determinant of wildfire risk—is not currently used for wildfire danger assessments because data are generally unavailable at the...
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Assessing Vulnerability of Vegetation and Wildlife Communities to Post-Fire Transformations to Guide Management of Southwestern Pine Forests and Woodlands
Wildfire is a natural and essential process in forest ecosystems, but characteristics of fire regimes that have shaped these landscapes over long time scales are changing with climate change and human activities. In some places, changes in fire size, frequency, and severity threaten to degrade essential ecosystem services that produce clean air and water, fertile soil for crop and wood production, and habitat for plant and animal species. Hence, it is urgent to understand how both our actions and inactions contribute to the vulnerability of forest ecosystems and to develop management practices that help sustain and conserve vegetation and wildlife communities in vulnerable forest systems. Our project will address...
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This climate and vegetation index dataset was collected from readily available open source data, such as Landsat. The data represents points across the northern Colorado plateau. The vegetation type was defined based on U.S. Geological Survey ReGAP data. Using compositing techniques by season we developed a dataset of lag and legacy for each point. We could then look to understand how both lag and legacy impacted vegetation production across the time series. In this dataset we focus on the soil adjusted vegetation index (SAVI), the standardized precipitation and evapotranspiration index (SPEI), and precipitation. Included in this dataset are climate lags of 3,6,9 and 12 months. Additionally, the legacy construct...
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