Dekker F.J.,Mojave National Preserve |
Hughson D.L.,Mojave National Preserve
Journal of Arid Environments | Year: 2014
Small springs in mountainous areas provide the only source of water for numerous wildlife species over a broad expanse of the Mojave Desert. A comprehensive inventory and annual surveys over nine years indicated that many such springs occur in canyons and ravines along the slopes and near the base of mountain ranges associated with small, locally recharged, perched aquifers and are drought ephemeral. Within the 643,112ha study area 135 spring systems consisting of 238 distinct surface water expressions were monitored. Reliability of available surface water was correlated with watershed catchment area and spring brook length. Geologic field mapping of a subset of 39 springs indicated that the area of colluvial sediment above barriers was correlated with persistence of surface water from year to year, but the area of phreatophyte vegetation supported by spring discharge and hydraulic conductivity of the sediment surface were not. Reliable spring discharge through several years of sustained drought depends upon sufficient groundwater storage. Watershed catchment area, spring brook length, and area of colluvial sediment appear to be predictors of discharge persistence during drought for certain types of montane springs. © 2014.
News Article | February 14, 2016
President Barack Obama has designated three California desert areas made up of some 1.8 million acres as national monuments, roughly doubling the amount of protected public land during his presidency. All three scenic desert areas lie east of Los Angeles, with two, namely Mojave Trails and Castle Mountains, are situated near the Californian border with Nevada. With the protection of the sections of the Mojave and Sonoran deserts, the federal government remains the owner of the land but will be prohibited from selling it, constructing new roads or allowing further development that is not aligned with ecological protection, recreation or flood control measures. “The California desert is a cherished and irreplaceable resource for the people of Southern California,” said interior secretary Sally Jewell last Friday. According to a White House statement, the new national monuments will link lands that are already protected, including the Mojave National Preserve, Joshua Tree National Park, and 15 wilderness areas. The move, they added, will permanently protect “key wildlife corridors” and offer animals and plants “the space and elevation range that they will need in order to adapt to the impacts of climate change.” Of the three new monuments, the Mojave Trails is the largest at 1.6 million acres and features rugged mountains and stunning sand dunes. It is considered a reteller of the American story with its historic trading routes, a transcontinental rail line and the country’s most famous highway, Route 66. The Sand to Snow National Monument boasts Southern California’s tallest mountain and showcases 154,000 acres of diverse terrain, while the Castle Mountains is the smallest at 20,920 acres yet home to awe-inspiring wildlife including golden eagles and mountain lions. In less than two years, this is the second time that the executive power acted to protect California wilderness areas after a stalled case in Congress – a disagreement stemming from partisan politics. In 2014, the president endowed the same protection on a 540-square mile portion of the San Gabriel Mountains after Representative Judy Chu’s attempt to win protection approval in the House. The White House said that President Obama has now protected over 265 million acres of water and land, which is more than any other U.S. presidency’s action.
Hughson D.L.,Mojave National Preserve |
Darby N.,Mojave National Preserve |
Dungan J.D.,Mojave National Preserve
California Fish and Game | Year: 2010
Motion-triggered cameras are useful in wildlife investigations but quantitative metrics derived from photographs potentially include substantial error. We compared six models of cameras placed sideby-side at a small spring in Mojave National Preserve, California, for 63 days in the spring of 2006, and for 40 days in the fall of 2007. Total number of different species detected varied by camera from 2 to 14 in the first trial and from 1 to 6 in the second. Total number of wildlife photographs taken by each camera ranged from 18 to 348 in the first trial and from 0 to 95 in the second. Photographic rates of a single species, mule deer (Odocoileus hemionus), differed by as much as 100% between two units of the same camera model. We did find, however, that the distribution of time intervals between photographs of mule deer was similar for different cameras. These results indicate that photographic rates and number of species detected by motion-triggered cameras can vary significantly even for identical models placed side by side, and have important implications regarding the interpretation of such data across areas.