Miguel Villarreal, PhD
Dr. Miguel Villarreal is a Research Geographer with the Western Geographic Science Center at Moffett Field, CA.
Wildfire at the Crossroads
Fire is an essential ecological process and management tool but can also be detrimental to life and property. Our findings provide a new depiction of fire regimes in the Sky Islands that can help inform fire management, restoration and regional conservation planning, fostered by local and traditional knowledge and collaboration among landowners and managers.
Remote Sensing of Biological Soil Crusts
Determining the spatial extent and condition of biocrusts across landscapes continues to present considerable challenges to scientists. Remote sensing offers promising opportunities to detect and characterize biocrust communities, differentiate among biocrust community types, and monitor changes in biocrust distribution across dryland landscapes globally.
Miguel’s research involves using earth observation systems and spatial analyses to better understand how disturbances such as wildfire, invasive species, and energy development affect ecosystems, ecosystem services, and human communities, and to provide land managers information to help reduce risk and facilitate recovery after a disturbance. His geographic focus is on water-limited (dryland) regions of the west, which are particularly sensitive to complex interactions between human land use, natural disturbances, and climate change.
Miguel’s current research projects include studies of wildfire and wildlife in the Sky Island region of the U.S.-Mexico borderlands, monitoring the impacts and recovery of oil and gas and solar energy developments on the Colorado Plateau and Mojave Deserts, and mapping and monitoring biological soil crusts and invasive grasses across the western US. He works closely with federal agency partners (NPS, USFWS, BLM, USFS, DOD) to develop and implement research projects.
Current and recent research projects
- Remote Sensing for Resource Management, Project Chief (2015-Present)
- Southwest Energy Development and Reclamation (SWEDR), Co-Project Chief (2015-Present)
- Biological soil crust ecology and function from space, Co-Project Chief (2020-Present)
- Southern Border Fuels Management Initiative: Strategies to reduce fire risk and improve viewsheds along the U.S. southern border, Co-Investigator (2019-Present)
- Remote Sensing for Monitoring Riverside East Solar Development Focus Area (DFA) and for Desert Energy Transmission Corridors, Principal Investigator (2021-Present)
- Assessing change in forest density and fuel loads in the absence of fire (1941-2018) at Lassen Volcanic NP using historic aerial photos, Principal Investigator (2019-Present)
- Evaluating the response of California Delta riparian ecosystems to anthropogenic and climate stressors, Principal investigator (2019-2021)
- Detection and monitoring of fire-prone early season invasive grasses in the Southwest, Co-investigator (2020-2021)
- Wildfire probability mapping based on regional soil moisture models. Co-investigator, (2020-2022)
- Assessing Vulnerability to Drought in Dryland Ecosystems of the Western U.S. Co-investigator, (2016-2018)
Professional Experience
2011-Present: Research Geographer, U.S. Geological Survey
2011-2013: Mendenhall Fellow, U.S. Geological Survey
2009-2011: Postdoctoral Research Associate, School of Natural Resources and the Environment, University of Arizona
2006-2009: Research Associate, Arizona Remote Sensing Center, University of Arizona
2001- 2005: Research Associate, Geography and Regional Development, University of Arizona
Education and Certifications
Ph.D. and M.A. from the University of Arizona
B.A. from the University of California, Davis
Science and Products
Historical analysis of riparian vegetation change in response to shifting management objectives on the Middle Rio Grande
Climate legacy and lag effects on dryland plant communities in the southwestern U.S.
Disturbance automated reference toolset (DART): Assessing patterns in ecological recovery from energy development on the Colorado Plateau
Decadal shifts in grass and woody plant cover are driven by prolonged drying and modified by topo‐edaphic properties
Multi-index time series monitoring of drought and fire effects on desert grasslands
Comparison of remote sensing indices for monitoring of desert cienegas
Continuous 1985-2012 Landsat monitoring to assess fire effects on meadows in Yosemite National Park, California
Modelling landscape-scale erosion potential related to vehicle disturbances along the U.S.-Mexico border
Remote sensing analysis of riparian vegetation response to desert marsh restoration in the Mexican Highlands
Influence of monsoon-related riparian phenology on yellow-billed cuckoo habitat selection in Arizona
Vegetation inventory, mapping, and classification report, Fort Bowie National Historic Site
Mapping landscape phenology preference of yellow-billed cuckoo with AVHRR data
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Historical analysis of riparian vegetation change in response to shifting management objectives on the Middle Rio Grande
Riparian ecosystems are valuable to the ecological and human communities that depend on them. Over the past century, they have been subject to shifting management practices to maximize human use and ecosystem services, creating a complex relationship between water policy, management, and the natural ecosystem. This has necessitated research on the spatial and temporal dynamics of riparian vegetatiAuthorsRoy Petrakis, Willem J.D. van Leeuwen, Miguel L. Villarreal, Paul Tashjian, Regina Dello Russo, Christopher A. ScottClimate legacy and lag effects on dryland plant communities in the southwestern U.S.
Climate change effects on vegetation will likely be strong in the southwestern U.S., which is projected to experience large increases in temperature and changes in precipitation. Plant communities in the southwestern U.S. may be particularly vulnerable to climate change as the productivity of many plant species is strongly water-limited. This study examines the relationship between climate and vegAuthorsErin Bunting, Seth M. Munson, Miguel L. VillarrealDisturbance automated reference toolset (DART): Assessing patterns in ecological recovery from energy development on the Colorado Plateau
A new disturbance automated reference toolset (DART) was developed to monitor human land surface impacts using soil-type and ecological context. DART identifies reference areas with similar soils, topography, and geology; and compares the disturbance condition to the reference area condition using a quantile-based approach based on a satellite vegetation index. DART was able to represent 26–55% ofAuthorsTravis W. Nauman, Michael C. Duniway, Miguel L. Villarreal, Travis B. PoitrasDecadal shifts in grass and woody plant cover are driven by prolonged drying and modified by topo‐edaphic properties
Woody plant encroachment and overall declines in perennial vegetation in dryland regions can alter ecosystem properties and indicate land degradation, but the causes of these shifts remain controversial. Determining how changes in the abundance and distribution of grass and woody plants are influenced by conditions that regulate water availability at a regional scale provides a baseline to compareAuthorsSeth M. Munson, Temuulen T. Sankey, George Z. Xian, Miguel L. Villarreal, Collin G. HomerMulti-index time series monitoring of drought and fire effects on desert grasslands
The Western United States is expected to undergo both extended periods of drought and longer wildfire seasons under forecasted global climate change and it is important to understand how these disturbances will interact and affect recovery and composition of plant communities in the future. In this research paper we describe the temporal response of grassland communities to drought and fire in souAuthorsMiguel L. Villarreal, Laura M. Norman, Steven Buckley, Cynthia S.A. Wallace, Michelle A. CoeComparison of remote sensing indices for monitoring of desert cienegas
This research considers the applicability of different vegetation indices at 30 m resolution for mapping and monitoring desert wetland (cienega) health and spatial extent through time at Cienega Creek in southeastern Arizona, USA. Multiple stressors including the risk of decadal-scale drought, the effects of current and predicted global warming, and continued anthropogenic pressures threaten aquatAuthorsNatalie R. Wilson, Laura M. Norman, Miguel L. Villarreal, Leila Gass, Ron Tiller, Andrew SalywonContinuous 1985-2012 Landsat monitoring to assess fire effects on meadows in Yosemite National Park, California
To assess how montane meadow vegetation recovered after a wildfire that occurred in Yosemite National Park, CA in 1996, Google Earth Engine image processing was applied to leverage the entire Landsat Thematic Mapper archive from 1985 to 2012. Vegetation greenness (normalized difference vegetation index [NDVI]) was summarized every 16 days across the 28-year Landsat time series for 26 meadows. DistAuthorsChristopher E. Soulard, Christine M. Albano, Miguel L. Villarreal, Jessica J. WalkerModelling landscape-scale erosion potential related to vehicle disturbances along the U.S.-Mexico border
Decades of intensive off-road vehicle use for border security, immigration, smuggling, recreation, and military training along the USA–Mexico border have prompted concerns about long-term human impacts on sensitive desert ecosystems. To help managers identify areas susceptible to soil erosion from anthropogenic activities, we developed a series of erosion potential models based on factors from theAuthorsMiguel L. Villarreal, Robert H. Webb, Laura M. Norman, Jennifer L. Psillas, Abigail S. Rosenberg, Shinji Carmichael, Roy E. Petrakis, Philip E. SparksRemote sensing analysis of riparian vegetation response to desert marsh restoration in the Mexican Highlands
Desert marshes, or cienegas, are extremely biodiverse habitats imperiled by anthropogenic demands for water and changing climates. Given their widespread loss and increased recognition, remarkably little is known about restoration techniques. In this study, we examine the effects of gabions (wire baskets filled with rocks used as dams) on vegetation in the Cienega San Bernardino, in the Arizona, SAuthorsLaura M. Norman, Miguel L. Villarreal, H. Ronald Pulliam, Robert L. Minckley, Leila Gass, Cindy Tolle, Michelle CoeInfluence of monsoon-related riparian phenology on yellow-billed cuckoo habitat selection in Arizona
Aim: The western yellow-billed cuckoo (Coccyzus americanus occidentalis), a Neotropical migrant bird, is facing steep population declines in its western breeding grounds owing primarily to loss of native habitat. The favoured esting habitat for the cuckoo in the south-western United States is low-elevation riparian forests and woodlands. Our aim was to explore relationships between vegetation pheAuthorsCynthia S.A. Wallace, Miguel L. Villarreal, Charles van RiperVegetation inventory, mapping, and classification report, Fort Bowie National Historic Site
A vegetation mapping and characterization effort was conducted at Fort Bowie National Historic Site in 2008-10 by the Sonoran Desert Network office in collaboration with researchers from the Office of Arid lands studies, Remote Sensing Center at the University of Arizona. This vegetation mapping effort was completed under the National Park Service Vegetation Inventory program which aims to completAuthorsSarah Studd, Elizabeth Fallon, Laura Crumbacher, Sam Drake, Miguel L. VillarrealMapping landscape phenology preference of yellow-billed cuckoo with AVHRR data
We mapped habitat for threatened Yellow-billed Cuckoo (Coccycus americanus occidentalis) in the State of Arizona using the temporal greenness dynamics of the landscape, or the landscape phenology. Landscape phenometrics were derived from Advanced Very High Resolution Radiometer (AVHRR) Normalized Difference Vegetation Index (NDVI) data for 1998 and 1999 by using Fourier harmonic analysis to analyzAuthorsCynthia S.A. Wallace, Miguel L. Villarreal, Charles van Riper - News