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The California Department of Fish and Game (CDFG) Vegetation Classification and Mapping Program (VegCAMP) and contractor Aerial Information Systems (AIS) created a fine-scale vegetation map of a portion of the western Mojave Desert in California. The mapped area is bounded to the west and south by USDA Ecoregional Subsection 322Ag of the Mojave Desert (Miles and Goudey 1997). To the east, the portion mapped by AIS (approx. 4,202,000 acres) is bounded by the borders of a vegetation map produced in 2004 for the Mojave Desert Ecosystem Program (MDEP). VegCAMP mapped a portion of the area mapped previously for the MDEP (approx. 776,000 acres) using the finer-scale rules and classification that AIS used for the larger...
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Mojave and Great Basin Upper Bajada and Toeslope distribution within the DRECP study area.This community was extracted from the Land/Use Natural Vegetation Communities dataset provided by Aerial Information Systems and the California Dept. of Fish and Game. Extractions were based on the GroupCommunity field.The California Department of Fish and Wildlife (CDFW) Vegetation Classification and Mapping Program (VegCAMP) and contractor Aerial Information Systems (AIS) created a fine-scale vegetation map of a portion of the western Mojave Desert in California. The mapped area is bounded to the west and south by USDA Ecoregional Subsection 322Ag of the Mojave Desert (Miles and Goudey 1997). To the east, the portion mapped...
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Intermontane Deep or Well-Drained Soil Scrub distribution within the DRECP study area.This community was extracted from the Land/Use Natural Vegetation Communities dataset provided by Aerial Information Systems and the California Dept. of Fish and Game. Extractions were based on the GroupCommunity field.The California Department of Fish and Wildlife (CDFW) Vegetation Classification and Mapping Program (VegCAMP) and contractor Aerial Information Systems (AIS) created a fine-scale vegetation map of a portion of the western Mojave Desert in California. The mapped area is bounded to the west and south by USDA Ecoregional Subsection 322Ag of the Mojave Desert (Miles and Goudey 1997). To the east, the portion mapped by...
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Five principal components are used to represent the climate variation in an original set of 12 composite climate variables reflecting complex precipitation and temperature gradients. The dataset provides coverage for future climate (defined as the 2040-2070 normal period) under the RCP4.5 emission scenarios. Climate variables were chosen based on their known influence on local adaptation in plants, and include: mean annual temperature, summer maximum temperature, winter minimum temperature, annual temperature range, temperature seasonality (coefficient of variation in monthly average temperatures), mean annual precipitation, winter precipitation, summer precipitation, proportion of summer precipitation, precipitation...
The recognition and characterization of aeolian dust in soil contribute to a better understanding of landscape and ecosystem dynamics of drylands. Results of this study show that recently deposited dust, sampled in isolated, mostly high-ground settings, is chemically and mineralogically similar on varied geologic substrates over a large area (15 000 km2) in the Mojave Desert. The silt-plus-clay fraction (fines) on these isolated surfaces is closely alike in magnetic-mineral composition, in contrast to greatly dissimilar magnetic compositions of rock surfaces of vastly different lithologies, on which the fines have accumulated. The fines, thus, are predominantly deposited dust. The amounts of potential nutrients...
What are current conditions for important park natural resources? What are the critical data and knowledge gaps? What are some of the factors that are influencing park resource conditions? Natural Resource Condition Assessments (NRCAs) evaluate and report on the above for a subset of important natural resources in national park units (hereafter, parks). Focal study resources and indicators are selected on a park-by-park basis, guided by use of structured resource assessment and reporting frameworks. Considerations include park resource setting and enabling legislation (what are this park's most important natural resources?) and presently available data and expertise (what can be evaluated at this time?). In addition...
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Natural landscapes in the Southwestern United States are changing. In recent decades, rising temperatures and drought have led to drier conditions, contributed to large-scale ecological impacts, and affected many plant and animal species across the region. The current and future trajectory of climate change underscores the need for managers and conservation professionals to understand the impacts of these patterns on natural resources. In this regional assessment of the Southwest Climate Change Initiative, we evaluate changes in annual average temperatures from 1951–2006 across major habitats and large watersheds and compare these changes to the number of species of conservation concern that are found within these...
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The California Department of Fish and Game (CDFG) Vegetation Classification and Mapping Program (VegCAMP) and contractor Aerial Information Systems (AIS) created a fine-scale vegetation map of a portion of the western Mojave Desert in California. The mapped area is bounded to the west and south by USDA Ecoregional Subsection 322Ag of the Mojave Desert (Miles and Goudey 1997). To the east, the portion mapped by AIS (approx. 4,202,000 acres) is bounded by the borders of a vegetation map produced in 2004 for the Mojave Desert Ecosystem Program (MDEP). VegCAMP mapped a portion of the area mapped previously for the MDEP (approx. 776,000 acres) using the finer-scale rules and classification that AIS used for the larger...
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Passive seismic data collection was done northwest of the Air Force Research Laboratory (AFRL) at Edwards Air Force Base using the horizontal-to-vertical spectral ratio (HVSR) technique. HVSR surveys were done at 43 locations between May and September 2018 to refine the understanding of the bedrock-alluvial aquifer transition zone downgradient from the AFRL. Specifically, the data were collected to help determine the depth to bedrock. The HVSR method is a passive seismic technique that uses a three-component seismometer to measure the vertical and horizontal components of ambient seismic noise. Seismic noise in the range of ~0.1 to 1 Hertz (Hz) is caused by ocean waves, large regional storms, and tectonic sources....
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Climate Distance Mapper is an interactive web mapping application designed to facilitate informed seed sourcing decisions and to aid in directing regional seed collections. Implemented as a shiny web application (Chang et al. 2017), Climate Distance Mapper is hosted on the web at: https://usgs-werc-shinytools.shinyapps.io/Climate_Distance_Mapper/. The application is designed to guide restoration seed sourcing in the desert southwest by allowing users to interactively match seed sources with restoration sites climatic differences – in the form of multivariate climate distance values – between restoration sites and the surrounding landscape. Climatic distances are based on a combination of variables likely to influence...
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The U.S. Geological Survey collected groundwater samples from 48 grid wells and 11 understanding wells screened in aquifers used for domestic supply in San Bernardino County, California, in 2018. The sites were sampled for the Mojave Basin (MOBS) Shallow Aquifer Study Unit of the California State Water Resources Control Board Groundwater Ambient Monitoring and Assessment (GAMA) Program Priority Basin Project’s assessment of the quality of groundwater resources used for domestic and small system drinking water supplies. The MOBS study unit covered the Upper, Middle, and Lower Mojave River groundwater basins, El Mirage groundwater basin, and part of the Harper Valley groundwater basin [California Department of Water...
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Five principal components are used to represent the climate variation in an original set of 12 composite climate variables reflecting complex precipitation and temperature gradients. The dataset provides coverage for future climate (defined as the 2040-2070 normal period) under the RCP8.5 emission scenarios. Climate variables were chosen based on their known influence on local adaptation in plants, and include: mean annual temperature, summer maximum temperature, winter minimum temperature, annual temperature range, temperature seasonality (coefficient of variation in monthly average temperatures), mean annual precipitation, winter precipitation, summer precipitation, proportion of summer precipitation, precipitation...
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During a multi-year demographic study of Agassiz’s desert tortoise (Gopherus agassizii) at the Desert Tortoise Research Natural Area (Natural Area), in the western Mojave Desert, USA, we recorded evidence of evidence of mesocarnivores that commonly prey on desert tortoises on a 7.77 square-kilometer study area. The study area included land inside and outside the fenced boundary of the Natural Area. We recorded locations, condition and recency of sign, and type of sign present at burrows, dens, and den complexes used by desert kit foxes (Vulpes macrotis), coyotes (Canis latrans), American badgers (Taxidea taxus), and bobcats (Lynx rufus). We also recorded scat piles by species using them, amount, and relative ages...
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Time-domain electromagnetic (TEM) surveys were done northwest of the Air Force Research Laboratory (AFRL) at Edwards Air Force Base. TEM surveys were done at 33 locations between May and October 2018 to refine the understanding of the bedrock-alluvial aquifer transition zone downgradient from the AFRL. TEM surveys (also called transient electromagnetic surveys) provide 1D resistivity soundings of the subsurface, which can be related to lithology and hydrogeology. In the TEM method, electrical current is cycled through a transmitter loop (Tx) wire, which in turn produces a primary magnetic field. When the current is abruptly terminated, a secondary magnetic field is induced in the earth, and it moves downward and...
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The Air Force Research Laboratory (AFRL) is about 7 kilometers southwest of Boron, California, and covers 320 square kilometers of Edwards Air Force Base. The AFRL consists of 12 facilities for testing full-size rocket engines, engine components, and liquid and solid propellants. The historical release of contaminants from rocket test stands, evaporation ponds, burn pits, catch basins, and leaking waste-collection tanks has contaminated groundwater in the AFRL. Groundwater aquifers near the AFRL are mostly restricted to fractured granitic bedrock, but previous studies indicate that groundwater and associated contaminants have moved into alluvium to the north and northwest. The U.S. Geological Survey (USGS) and the...
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Electrical resistivity tomography (ERT) surveys were done northwest of the Air Force Research Laboratory (AFRL) at Edwards Air Force Base. ERT surveys were done at four locations in May through June of 2018 to refine the understanding of the bedrock-alluvial aquifer transition zone downgradient from the AFRL. The ERT technique injects direct-current electricity with known voltage and current into the earth using a series of electrodes and measures the resulting resistivity. This technique is generally limited to investigations of aquifer properties less than 100 meters below land surface. Data from other geophysical techniques co-located with the ERT data, including time-domain electromagnetics and horizontal-to-vertical...
The recognition and characterization of aeolian dust in soil contribute to a better understanding of landscape and ecosystem dynamics of drylands. Results of this study show that recently deposited dust, sampled in isolated, mostly high-ground settings, is chemically and mineralogically similar on varied geologic substrates over a large area (15 000 km2) in the Mojave Desert. The silt-plus-clay fraction (fines) on these isolated surfaces is closely alike in magnetic-mineral composition, in contrast to greatly dissimilar magnetic compositions of rock surfaces of vastly different lithologies, on which the fines have accumulated. The fines, thus, are predominantly deposited dust. The amounts of potential nutrients...
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Studies were conducted in the central Mojave Desert to quantify how creosote bushes (Larrea tridentata) respond to physical damage during large-scale military training exercises. Creosote bush possesses a resilient growth form that recovers from repeated physical damage via resprouts arising from meristems in stem bark below severed or crushed canopy units. At high levels of disturbance by heavy vehicles, nearly all individuals showed measurable breakage, but without additional damage each plant can regain a full canopy within 5 years under arid field conditions. Resprouts exhibited more vigorous growth and doubled the biomass accumulation stimulated by high rainfall of 1998, an El Niño year, vs. a normal year....


map background search result map search result map Resprout characteristics of creosote bush (Larrea tridentata) when subjected to repeated vehicle damage Mojave and Great Basin Upper Bajada and Toeslope - Natural Community Distribution, DRECP Intermontane Deep or Well-Drained Soil Scrub - Natural Community Distribution, DRECP Land Cover/Natural Vegetation Communities (Group Level), Pinto Lucerne Valley and Eastern Slopes, DRECP Land Cover/Natural Vegetation Communities (Group Level), Owens River Valley, DRECP Natural Resource Condition Assessments Managing Changing Landscapes in the Southwestern United States Principal components of climate variation in the Desert Southwest for the future time period 2040-2070 (RCP 4.5) Climate Distance Mapper R Script Study Boundary and Grid Cells for the Mojave Basin Shallow Aquifer Study Unit Surface geophysics investigations at Edwards Air Force Research Laboratory, Antelope Valley, California, 2018 Ground-Based Time-Domain Electromagnetic Data Collected at Edwards Air Force Research Laboratory, Antelope Valley, California, 2018 Electrical Resistivity Tomography Data at Edwards Air Force Research Laboratory, Antelope Valley, California, 2018 Principal components of climate variation in the Desert Southwest for the future time period 2040-2070 (RCP 8.5) Horizontal-to-Vertical Seismic Ratio Passive-Seismic Data Collected at Edwards Air Force Research Laboratory, Antelope Valley, California, 2018 Evidence of Mammalian Carnivores at the Desert Tortoise Research Natural Area, Western Mojave Desert, USA, between 1989 and 2012. Surface geophysics investigations at Edwards Air Force Research Laboratory, Antelope Valley, California, 2018 Ground-Based Time-Domain Electromagnetic Data Collected at Edwards Air Force Research Laboratory, Antelope Valley, California, 2018 Horizontal-to-Vertical Seismic Ratio Passive-Seismic Data Collected at Edwards Air Force Research Laboratory, Antelope Valley, California, 2018 Electrical Resistivity Tomography Data at Edwards Air Force Research Laboratory, Antelope Valley, California, 2018 Evidence of Mammalian Carnivores at the Desert Tortoise Research Natural Area, Western Mojave Desert, USA, between 1989 and 2012. Resprout characteristics of creosote bush (Larrea tridentata) when subjected to repeated vehicle damage Study Boundary and Grid Cells for the Mojave Basin Shallow Aquifer Study Unit Land Cover/Natural Vegetation Communities (Group Level), Pinto Lucerne Valley and Eastern Slopes, DRECP Intermontane Deep or Well-Drained Soil Scrub - Natural Community Distribution, DRECP Mojave and Great Basin Upper Bajada and Toeslope - Natural Community Distribution, DRECP Managing Changing Landscapes in the Southwestern United States Climate Distance Mapper R Script Principal components of climate variation in the Desert Southwest for the future time period 2040-2070 (RCP 4.5) Principal components of climate variation in the Desert Southwest for the future time period 2040-2070 (RCP 8.5) Natural Resource Condition Assessments