Deserts


 * Deserts**





1) Deser occurat at low attitude. 2) Cold desert coours in the basin and range area of Utah and Nevada and in parts of Asia. Desert cover about 20 of the Earth's total surface land. You can only find desert where rainfall is less than 50cm/year. (emiliechien) || 1)Hot and dry desert Vegetations:Yuccas, ocotillo, turpentine bush, prickly pears, false mesquite, sotol, ephedras, agaves and brittlebush. Animals :small nocturnal (active at night) carnivores, burrowers and kangaroo rats,insects, arachnids, reptiles and birds. 2)Semiarid desert Vegetation: Creosote bush, bur sage (//Franseria dumosa// or //F. deltoidea//), white thorn, cat claw, mesquite, brittle bushes (//Encelia farinosa//), lyciums, and jujube. Animals : kangaroo rats, rabbits, and skunks; insects like grasshoppers and ants; reptiles are represented by lizards and snakes; and birds such as burrowing owls and the California thrasher. 3)costal desert Vegetation: salt bush, buckwheat bush, black bush, rice grass, little leaf horsebrush, black sage, and chrysothamnus. Animals: fairy shrimps ,insects, mammals (coyote and badger), amphibians (toads), birds (great horned owl, golden eagle and the bald eagle), and reptiles (lizards and snakes). 4) cold desert Vegetation: deciduous, plants that have spiny leaves. Animals: jack rabbits, kangaroo rats, kangaroo mice, pocket mice, grasshopper mice, and antelope ground squirrels. ( emilie chien ) ||
 * Geographic Distribution: || There are two places where desert is likely to take place or occur.
 * Climate: || The temeperature of days and nights in desert are very different. Unlike other biome, desert has its own seaseonal temperature range. Desert has an extremely high daytime temperatures, and low nighttime temperatures as well as an extremely low humidity) . Generally speaking, the daytime temeperature of daytime in desert can reach 45 °C/113 °F and 0 °C/32°F at nighttime. In summer time, the temeperature is even high than that. In winter ,desert can drop significantly below 0 °C/32°F. (emiliechien)  ||
 * Soil Fertility: || Soils in desert are usually consist of a lot of bundant nutrients since in desert there is only little or no organic matter. Animals and plants who lives in desert only need water to increase its productivity. (emiliechien) ||
 * Typical Plants: || Most deserts have various amount of different kinds of vegetations and animals, such as vertebrate and invertebrate animals. There are four different types of desert exist in the world. Each desert has its own special animals and vegetation. Due to the fact that large animals are not capable of storing sufficient water within their body and withstanding the heat. Deserts often provide little shelter from the sun for large animals. Therefore, t here are relatively few large mammals in deserts. Instead,the dominant animals of warm deserts are mostly nonmammalian vertebrates, such as reptiles. Mammals who survives in desert are usually small.
 * Human Impact Issues: || Humans have damaged the dessert in many ways, such as killing the vegetation and the making roadskills out of species in the region and many more. Because vegetation in the dessert requires alot of time to grow, killing the vegeation through off-road driving will decrease the number of plant species, which will then also decrease the number of speices that rely on the vegetation. Furthermore, excessive hunting species has also contributed to the decline of the dessert, which affected other species that depended on the hunted species. In addition, mining and drilling has contributed to the change of dessert by changing the area where animals and plants are used to living in, such as the saguaro cactus needs shade in order to grow, which is constantly changing due to mining and drilling. ( Charles Lee) ||

Reources: [|http:en.wikipedia.orgwikiDesert] [|http www.ucmp.berkeley.eduexhibitsbiomesdeserts.php] http://library.thinkquest.org/C0113340/text/impact/impact.desert.mining.html