Desert is an area where evaporation exceeds precipitation. Annual precipitation is low and is usually scattered unevenly throughout the year. Deserts cover about 30% of the earth’s land surface. Largest deserts are found in the interiors of continents. There are three types of deserts:
· Tropical desert
· Temperate deserts
· Cold deserts
Deserts can be found in in North and South America, Australia, Africa, Syria, the Arabian Peninsula, Israel and Antarctica.
Tropical desert—the tropical desert is hot and dry most of the year. The average monthly temperatures are in the mid30os Celsius (90oF). Daytime temperatures can reach 50oC (120oF). Precipitation levels are low and average to less than 25 cm (10 in) each year.
Temperate deserts—daytime temperatures are high in summer and low in winter. The average annual temperature is 20-25oC. Average annual precipitation is less than 25 cm a year. Majority of precipitation comes in the form of snow and fog. There is more precipitation in the temperate desert than in the tropical desert.
Cold deserts—the winters are long and cold; the summers are warm, moist and short. Winter temperatures are between -2 and 4° C. Summer temperatures are between 21-26° C. The mean annual precipitation ranges from 15-26 cm.
In the absence of water, desert soil is either fine-textured sand or loose rock and gravel. Desert sand is well drained and does not allow water to sit on top of it. The water soaks into the ground very quickly. Deserts with more rainfall have soils that have higher levels of salt concentration; deserts with less minimal rainfall have little salt concentration in the soil. Because there is low moisture in the desert, particle of sand are easily blown away, leaving remaining particles to tightly pack together, creating “desert pavement.”
Major Vegetation: Cacti and other succulent plants
Animals: Jack Rabbit, Camel, Phainopepla Hummingbird, Kangaroo Mice, Tarantulas, Rattle Snake, Foxes, Deer, Wolves, Lizards.
Traits that would enhance survivability:
Plant adaptations- Adaptations that would enhance plant survivability in the desert biome would be the ability to store water for a long period of time and the ability to withstand hot weather. Plants like cactuses and other succulent plants take up water and store the water in their leaves and stems. Some desert plants have developed taproots, roots that allow plant to reach down thirty meters below the surface to get water. Other plants have developed shallow roots to catch water after brief showers. In order to conserve water, evergreen plants have wax-coated leaves that reduce water loss. In order to survive, plants have also grown spines to protect themselves from being eaten by herbivores that are looking for water and food.
Animal and insect adaptations—Like plants, animals and insects also adapt based on heat as well as the limited resource of water the desert offers. Other animals have adapted by burrowing themselves underground during the day to hide themselves from the hot sun and heat. Many animals are nocturnal and only come out when it is cooler at night. Other animals, like the Fennec Fox have developed large ears to pass of heat quickly. The Fennec Fox has also developed fur on the bottom of its paws to protect them from being burned by the hot sand.
Human activities that disrupt the desert biome include off road driving, the collection of animals and plants, hunting and building development. When people drive off road vehicles in unrestricted areas vegetation in destroyed. As a resulting factor of destroyed vegetation, food for animals is also harmed. Off road driving is also harmful to animals that live in the sand. Humans have also destroyed the desert by collecting animals and plants. Rare species of cacti are extinct because people have been collecting them. People have also collected animals out of the biome to sell as pets to people. Overhunting is also another human activity that affects the desert. The result of over hunting is the extinction of plants and animals. The development of buildings and businesses has also affected the desert biome because many desert streams, rivers, and lakes once used by animals have been drained for industries, people, and farms. Pollution from drilling also causes damage to the desert. The pollution increases global warming, which, in turn changes weather patterns. It is important to note that when these climatic alterations occur, it disrupts the balance needed to maintain the dry, arid conditions of the desert. In addition deserts are also being used as dump sites for nuclear wastes and nuclear testing grounds.
Possible solutions: Laws have been passed to preserve plant and animal life in the desert. Parks have also been created to preserve plants and animal species. Laws against plant and animal collection have also been passed. Another solution is to introduce fines to those who participate in off road driving. A solution to reduce emissions is to create laws limiting the amount of drilling a company can do. To prevent the desert from becoming a dump site, regulators should introduce fines to those who dump the nuclear waste in the desert.