A5060704951- Rangeland and Wildlife Management
- Remote Sensing in Agriculture
- Species Distribution and Climate Change
- Wildlife Ecology and Conservation
- Ecology and Vegetation Dynamics Studies
- Fire effects on ecosystems
- Plant Water Relations and Carbon Dynamics
- Remote Sensing and LiDAR Applications
- Archaeology and Natural History
- Land Use and Ecosystem Services
- Botany, Ecology, and Taxonomy Studies
- Soil Geostatistics and Mapping
- Climate change and permafrost
- Remote Sensing and Land Use
- Cryospheric studies and observations
- Arctic and Russian Policy Studies
- Geological Studies and Exploration
- Turtle Biology and Conservation
- Indigenous Studies and Ecology
- Primate Behavior and Ecology
- Sustainability and Climate Change Governance
- Climate change impacts on agriculture
- Plant and animal studies
- Forest Management and Policy
- Urban Heat Island Mitigation
United States Geological Survey
2008-2023
Western Geographic Science Center
2008-2022
Arizona Geological Survey
2005-2022
University of Arizona
2000-2014
Astrogeology Science Center
2014
Flagstaff Medical Center
2007
Southwest Biological Science Center
2007
Woody plant encroachment, a worldwide phenomenon, is major driver of land degradation in desert grasslands. encroachment by shrub functional types ultimately leads to the formation patchy landscape with fertile patches interspaced nutrient‐depleted bare soil patches. This considered be an irreversible process and degradation. Recent studies have indicated that early stages when there sufficient herbaceous connectivity, fires (prescribed or natural) might provide some reversibility negatively...
The Western United States is expected to undergo both extended periods of drought and longer wildfire seasons under forecasted global climate change it important understand how these disturbances will interact affect recovery composition plant communities in the future. In this research paper we describe temporal response grassland fire southern Arizona, where land managers are using repeated, prescribed as a habitat restoration tool. Using 25-year atlas locations, paired sites with multiple...
The increasing spread and abundance of an invasive perennial grass, buffelgrass (Pennisetum ciliare), represents a critical threat to the native vegetation communities Sonoran desert in southern Arizona, USA, where eradication is high priority for resource managers. Herbicidal treatment most effective when actively growing, but remoteness infestations erratic timing length species’ growth periods confound treatment. goal our research promote management by using remote sensing data detect...
First posted May 19, 2009 For additional information, contact: Director, Western Ecological Research CenterU.S. Geological Survey3020 State University Drive EastModoc Hall, Room 3006Sacramento, CA 95819 Habitat modeling is an important tool used to simulate the potential distribution of a species for variety basic and applied questions. The desert tortoise (Gopherus agassizii) federally listed threatened in Mojave Desert parts Sonoran California, Nevada, Utah, Arizona. Land managers this...
An important metric to monitor for optimizing water use in agricultural areas is the amount of cropland left fallowed, or unplanted. Fallowed croplands are difficult model because they have many expressions; example, can be managed and remain free vegetation abandoned become weedy if climate that season permits. We used 250 m, 8-day composite Moderate Resolution Imaging Spectroradiometer normalized difference index data develop an algorithm routinely map status (planted fallowed) with over...
The Sonoran Desert and Apache Highlands ecoregions of North America are areas exceptionally high plant vertebrate biodiversity. However, much the biodiversity is supported by only a few vegetation types with limited distributions, some which increasingly threatened changing land uses. We assessed impacts two future urban growth scenarios on in binational watershed Arizona, USA Sonora, Mexico. quantified mapped terrestrial species richness using Wildlife Habitat Relation models validated...
In the arid Mojave Desert, phenological response of vegetation is largely dependent upon timing and amount rainfall, maps annual plant cover at any one point in time can vary widely. Our study developed relative growth models as proxies for using metrics that captured variability Moderate-Resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) satellite images. We used landscape phenologies revealed MODIS data together with ecological knowledge seasonality to develop a...
In 2005, fire ignited by humans swept from Yuma Proving Grounds into Kofa National Wildlife Refuge, Arizona, burning ca. 9,255 ha of Wilderness Area. Fuels were predominantly the native forb Plantago ovata. Large fires at low elevations rare in 19th and 20th centuries, fueled vegetation are undocumented southwestern deserts. We estimated area damaged using Moderate Resolution Imaging Spectroradiometer Normalized Difference Vegetation Index, which more accurate reduce subjectivity aerial...
Long-term vegetation monitoring efforts have become increasingly important for understanding ecosystem response to global change. Many traditional methods can be infrequent and limited in scope. Ground-based LiDAR is one remote sensing method that offers a clear advancement monitor dynamics at high spatial temporal resolution. We determined the effectiveness of detect intra-annual variability structure long-term Sonoran Desert plot dominated by cacti, deciduous evergreen shrubs. Monthly...
Abstract Question The decline and loss of perennial vegetation in dryland ecosystems due to global change pressures can alter ecosystem properties initiate land degradation processes. We tracked changes using remote sensing address the question how prolonged drought land‐use intensification have affected cover across a desert region early 21st century? Location Mojave Desert, southeastern California, southern Nevada, southwestern Utah northwestern Arizona, USA . Methods coupled...
This paper details a method to create regional models of perennial vegetation cover using pre-existing field data and satellite imagery. Total is an important ecological attribute desert ecosystems, including the Mojave Desert, USA, area 125,000 km2. Moderate-Resolution Imaging Spectroradiometer Enhanced Vegetation Index (MODIS-EVI) were coupled with measurements total plot elevation stepwise linear regression techniques two cover. The final produced R 2 0.82 0.81, respectively, yielded maps...
Abstract Buffelgrass ( Cenchrus ciliaris syn. Pennisetum ciliare ) was introduced to Sonoran Desert in the early 20th century and has become widespread at low elevations. This perennial bunchgrass accumulates abundant biomass that can carry fires through ecosystems not adapted fire, resulting devastating impacts for native cacti other plant animal life. is most effectively managed application of herbicide when grass least 50% green. Because rapidly greens up following summer monsoon...
The Colorado River Basin (CRB) includes seven states and provides municipal industrial water to millions of people across all major southwestern cities both inside outside the basin. Agriculture is largest part CRB economy crop production depends on irrigation, which accounts for about 74% total demand cross region. A better understanding irrigation demands critically needed as temperatures continue rise drought intensifies, potentially leading shortages Yet, past research dynamics has...
Abstract Aim The western yellow‐billed cuckoo ( C occyzus americanus occidentalis ), a N eotropical migrant bird, is facing steep population declines in its breeding grounds owing primarily to loss of native habitat. favoured nesting habitat for the south‐western U nited S tates low‐elevation riparian forests and woodlands. Our aim was explore relationships between vegetation phenology patterns captured by satellite phenometrics distribution cuckoo, use this information map Location A...
Our study used geostatistics to extract measures that characterize the spatial structure of vegetated landscapes from satellite imagery for mapping endangered Sonoran pronghorn habitat. Fine resolution IKONOS data provided information at scale individual trees or shrubs permitted analysis vegetation and pattern. We derived images landscape by calculating local estimates nugget, sill, range variogram parameters within 25 × 25-m image windows. These parameters, which describe autocorrelation...
This report summarizes the development of a binational vegetation map developed for Santa Cruz Watershed, which straddles southern border Arizona and northern Sonora, Mexico. The was created as an environmental input to Watershed Ecosystem Portfolio Model (SCWEPM) that is being by U.S. Geological Survey watershed. SCWEPM map-based multicriteria evaluation tool allows stakeholders explore tradeoffs between valued ecosystem services at multiple scales within participatory decision-making...
The Ambos Nogales watershed, which surrounds the twin cities of Nogales, Arizona, United States and Sonora, Mexico, has a history problems related to flooding. This paper describes process creating high-resolution, binational land-cover dataset be used in modeling watershed. Automated Geospatial Watershed Assessment tool will model watershed identify focal points for planning efforts anticipate ramifications implementing detention reservoirs at certain planes.
California's Central Valley, USA is a critical component of the Pacific Flyway despite loss more than 90% its wetlands. Moist soil seed (MSS) wetland plants are now produced by mimicking seasonal flooding in managed wetlands to provide an essential food resource for waterfowl. Managers need MSS plant area and productivity estimates support waterfowl conservation, yet this remains unknown at landscape scale. Also effects recent drought on have not been quantified. We generated Landsat-derived...
This report describes the methods used to derive various elevation-derivative grids that were inputted Mojave Desert Tortoise Habitat model (L. Gass and others, unpub. data). These grids, which capture information on surface roughness topographic characteristics, are a subset of environmental datasets evaluated for tortoise habitat model. is major importance U.S. Fish Wildlife Service, charged with management this threatened population, including relocating displaced tortoises areas...