Miguel Villarreal, PhD
Biography
Miguel Villarreal is a Research Geographer with the Western Geographic Science Center in Menlo Park, CA. Miguel received his Ph.D. and M.A. from the University of Arizona and B.A. from the University of California, Davis.
Research and 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
Science and Products
Soil Compaction and Erosion
Extensive off-highway vehicle (OHV) use on desert lands can directly and indirectly lead to human health problems and impact soil, vegetation, and wildlife habitat. Soil pulverization and loosening caused by OHVs contribute to dust hazards, and to respiratory illnesses and diseases (e.g., valley fever) in adjacent, downwind communities. Repeated soil compaction by OHVs can also degrade...
Remote Sensing of Biological Soil Crusts
Biological soil crusts (biocrusts, photoautotrophic soil surface communities comprised of cyanobacteria, algae, bryophytes, lichens, and fungi, occur in drylands globally where they contribute to ecosystem functioning by increasing soil stability, reducing dust emissions, and modifying soil resource availability (e.g., water, nutrients) (Fig 1.3.1). Despite increasing recognition and interest...
Remote Sensing of Invasive Annual Grasses
One of the major ecological consequences of increasing global connectivity is the introduction, establishment, and spread of non-native species into new ecosystems. The rate and extent of biological invasions continues to increase globally, often at considerable environmental and economic costs. Once established, non-native species can transform ecosystems, complicating land management...
Remote Sensing of Energy Development
Oil and gas development across the western United States has increased substantially in recent decades, including within the Colorado Plateau. The Colorado Plateau is a high desert region of grasslands, shrublands, and woodlands and is home to a large number of world-renowned national and tribal parks and monuments (e.g., Grand Canyon, Zion, Bryce, Arches, Canyonlands, Monument Valley, and...
Remote Sensing and Dryland Management
Drylands (areas characterized by low precipitation, high evapotranspiration, and low soil moisture) occupy around 40-45% of the earth’s surface. Many drylands contain high biodiversity and provide essential ecosystem services (e.g., livestock forage, agricultural production, pollination) for nearly 1/3 of the world’s population who live in drylands. Given limited precipitation and other...
Ecosystem Modelling and Decision Support
The Ecosystem Modelling and Decision Support Project seeks to understand how drivers of ecosystem change like wildfire, drought, and land use affected past spatial and temporal patterns of vegetation communities and wildlife. Research methods involve 1) analyzing field-collected information (e.g. long-term plot/transect data, repeat photography) on soils, vegetation, and/or wildlife with...
Southwest Energy Development and Drought (SWEDD)
Deserts of the southwestern US are replete with oil and gas deposits as well as sites for solar, wind, and geothermal energy production. In the past, many of these resources have been too expensive to develop, but increased demand and new technologies have led to an increase in exploration and development. However, desert ecosystems generally have low resilience to disturbance. More frequent,...
Contemporary fire regimes provide a critical perspective on restoration needs in the Mexico-United States borderlands
The relationship between people and wildfire has always been paradoxical: fire is an essential ecological process and management tool, but can also be detrimental to life and property. Consequently, fire regimes have been modified throughout history through both intentional burning to promote benefits and active suppression to reduce risks....
Villarreal, Miguel L.; Iniguez, Jose M.; Flesch, Aaron D.; Sanderlin, Jamie S.; Cortés Montaño, Citlali; Conrad, Caroline Rose; Haire, Sandra L. Ultra‐high‐resolution mapping of biocrusts with Unmanned Aerial Systems
Biological soil crusts (biocrusts) occur in drylands globally where they support ecosystem functioning by increasing soil stability, reducing dust emissions and modifying soil resource availability (e.g. water, nutrients). Determining biocrust condition and extent across landscapes continues to present considerable challenges to scientists and...
Havrilla, Caroline; Villarreal, Miguel L.; DiBiase, Jacob; Duniway, Michael C.; Barger, Nichole Wildfire risk and hazardous fuel reduction treatments along the US-Mexico border: A review of the science (1985-2019)
The ecosystems along the border between the United States and Mexico are at increasing risk to wildfire due to interactions among climate, land-use, and fuel loads. A wide range of fuel treatments have been implemented to mitigate wildfire and its threats to valued resources, yet we have little information about treatment effectiveness. To fill...
Laushman, Katherine Mary; Munson, Seth M.; Titus, Timothy N. Rating fire danger from the ground up
Soil moisture information could improve assessments of wildfire probabilities and fuel conditions, resulting in better fire danger ratings.
Levi, Matthew; Krueger, Erik S.; Snitker, Grant J.; Ochsner, Tyson; Villarreal, Miguel L.; Elias, Emile H.; Peck, Dannele E. A mosaic of land tenure and ownership creates challenges and opportunities for transboundary conservation in the US-Mexico borderlands
In the Madrean Sky Islands of western North America, a mixture of public and private land ownership and tenure creates a complex situation for collaborative efforts in conservation. In this case study, we describe the current ownership and management structures in the US-Mexico borderlands where social, political, and economic conditions create...
Villarreal, Miguel L.; Haire, Sandra L.; Juan Carlos Bravo; Norman, Laura M. Landsat time series assessment of invasive annual grasses following energy development
Invasive annual grasses are of concern in many areas of the Western United States because they tolerate resource variability and have high reproductive capacity, with propagules that are readily dispersed in disturbed areas like those created and maintained for energy development. Early-season invasive grasses “green up” earlier than the most...
Villarreal, Miguel L.; Soulard, Christopher E.; Eric Waller Distant neighbors: recent wildfire patterns of the Madrean Sky Islands of southwestern United States and northwestern Mexico
BackgroundInformation about contemporary fire regimes across the Sky Island mountain ranges of the Madrean Archipelago Ecoregion in the southwestern United States and northern Mexico can provide insight into how historical fire management and land use have influenced fire regimes, and can be used to guide fuels management, ecological restoration,...
Villarreal, Miguel L.; Haire, Sandra L.; Iniguez, Jose M.; Cortés Montaño, Citlali; Poitras, Travis B. Landsat time series analysis of fractional plant cover changes on abandoned energy development sites
Oil and natural gas development in the western United States has increased substantially in recent decades as technological advances like horizontal drilling and hydraulic fracturing have made extraction more commercially viable. Oil and gas pads are often developed for production, and then capped, reclaimed, and left to recover when no longer...
Waller, Eric K.; Villarreal, Miguel L.; Poitras, Travis B.; Nauman, Travis W.; Duniway, Michael C. Evaluating and monitoring forest fuel treatments using remote sensing applications in Arizona, U.S.A.
The practice of fire suppression across the western United States over the past century has led to dense forests, and when coupled with drought has contributed to an increase in large and destructive wildfires. Forest management efforts aimed at reducing flammable fuels through various fuel treatments can help to restore frequent fire regimes and...
Petrakis, Roy; Villarreal, Miguel L.; Wu, Zhuoting; Hetzler, Robert; Middleton, Barry R.; Norman, Laura M. Identifying optimal remotely-sensed variables for ecosystem monitoring in Colorado Plateau drylands
Water-limited ecosystems often recover slowly following anthropogenic or natural disturbance. Multitemporal remote sensing can be used to monitor ecosystem recovery after disturbance; however, dryland vegetation cover can be challenging to accurately measure due to sparse cover and spectral confusion between soils and non-photosynthetic vegetation...
Poitras, Travis B.; Villarreal, Miguel L.; Waller, Eric K.; Nauman, Travis W.; Miller, Mark E.; Duniway, Michael C.
Evaluating land-use change scenarios for the Puget Sound Basin, Washington, within the ecosystem recovery target model-based framework
The Puget Sound Basin, Washington, has experienced rapid urban growth in recent decades, with varying impacts to local ecosystems and natural resources. To plan for future growth, land managers often use scenarios to assess how the pattern and volume of growth may affect natural resources. Using three different land-management scenarios for the...
Villarreal, Miguel L.; Aiello, Danielle; Labiosa, Bill 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...
Petrakis, Roy; van Leeuwen, Willem J.D.; Villarreal, Miguel L.; Tashjian, Paul; Dello Russo, Regina; Scott, Christopher A.
Wildfire at the Crossroads
The relationship between people and wildfire has always been paradoxical: fire is an essential ecological process and management tool but can also be detrimental to life and property. Consequently, fire regimes have been modified throughout history through both intentional burning to promote benefits and active suppression to reduce risks. Reintroducing fire and its