wander in from nearby mountains to escape periods of heavy snow The park also provides homes for 52 species of mammals 44 species of reptiles and two species of amphibians 3 It also has a vast number of arthropods including 75 species of butterflies 4 RESTORING THE DESERT JTNP’s land was dotted with hundreds of mines which were created by prospectors in the 1800s Native plants struggled to grow throughout much of the area Some areas had been stripped by miners for fuel and for mining props while others had been cleared by homesteaders for unsuccessful attempts at dryland farming Hundreds of miles of roads snaked through the desert People could easily drive into sensitive areas where they might trample or steal unique desert plants Traffic also brought seeds from non-native plants In the 1970s managers started tackling challenges in JTNP beginning with the tamarisk tree an invasive species Originally from Eurasia tamarisk was 6 NORTH AMERICAN DESERTS Four major deserts cover vast territories in North America Though all are dry location and rainfall patterns have lent different characteristics to each The Sonoran Desert stretches from southern Arizona and California down into Mexico Its mild winters and sporadic summer downpours nurture a diverse mix of temperate and tropical plant species The colder and slightly wetter Mojave Desert covers an area from southern California north to Nevada Arizona and Utah The Chihuahuan Desert reaches farthest south from southern New Mexico and Texas and into Mexico although it frequently suffers freezes in winters because of its high elevation The cold Great Basin Desert is the highest and farthest north of the four With parts reaching south into Arizona and New Mexico it also stretches north to Oregon and Idaho
deliberately planted by gardeners and landscapers to make windbreaks and shade These trees roots drink from deep underground stealing water from native species and leaching salt into the soil JTNP staff trekked far and wide throughout the national park to destroy tamarisks that had found their way to many remote springs and oases Soon managers added new targets such as Asian mustard tumbleweed and invasive grasses These non-native grasses include fountain grass which outcompetes native bunch grasses and two grasses that feed large fires in areas that are not adapted to burn Over time people at JTNP have removed thousands of invasive plants freeing springs in the park from both tamarisks and fountain grass Getting rid of unwanted species is one part of restoration but another key step is returning native species Pieces of land in JTNP had never fully recovered from the destruction wrought by miners and homesteaders Early attempts to replant old gravel pits stalled as seeds struggled to germinate and 7 HISTORY OF JTNP In the 1920s Pasadena California resident Minerva Hoyt became concerned by the loss of desert vegetation to cactus poachers These poachers snatched cacti from the desert and sold them for cactus gardens in places like Los Angeles Hoyt started a conservation movement that led to the establishment of what was then the Joshua Tree National Monument in 1936 In 1976 the government designated approximately 80 percent of the monument as wilderness protected from further roads and mechanized vehicles 5 In 1994 a growing awareness of the desert as a unique and valuable ecosystem led to the California Desert Protection Act Along with increased protections for other deserts the act changed Joshua Tree from a national monument into a national park and expanded it to its current size Since 2009 85 percent of JTNP is classified as wilderness Viewed from the roadside the dry land only hints at hidden vitality but closer examination reveals a giant mosaic of an ecosystem intensely beautiful and complex 6 A description of JTNP from National Parks of the American West
seedlings frequently died Without better methods JTNP had no hope of rehabilitating large areas The staff started the Center for Arid Lands Restoration CALR in 1986 to research and develop new restoration techniques They found that desert plants survived better when they were started in the nursery before being transplanted into arid conditions In the 1990s JTNP began to close roads throughout the park Along with spreading invasive species roads favor traffic which becomes a threat for wildlife such as the desert tortoise Eventually more than 167 miles 269 km were retired from active use 7 To disguise closed roads from drivers who might be tempted to turn down them staff concentrated their work near intersections At some intersections they rehabilitated the desert with pitting and vertical mulching Pitting is creating holes in the soil that help trap water from infrequent desert rains Vertical mulching is a technique of burying dead plant material upright in the soil which often blends Tamarisk trees thrive in habitats around water 9
