The Desert
Description/ Characteristics
Deserts cover about one fifth of the Earth's land surface. Deserts can be very hot or very cold. Most do not have many plants. Most Hot and Dry Deserts are near the Tropic of Cancer or the Tropic of Capricorn. Cold Deserts are near the Arctic part of the world. The most characterizing feature it rainfall: or lack thereof. Hot and Dry Deserts usually have very little rainfall and/or concentrated rainfall in short periods between long rainless periods. This averages out to under 15 cm a year. Cold Deserts usually have snow and rain during spring. This averages out to 15 - 26 cm a year. Hot and Dry Deserts are warm throughout the fall and spring seasons and very hot during the summer. The winters usually have very little if any rainfall. Cold Deserts have quite a bit of snow during winter. Hot and Dry Deserts’ temperature ranges from 20 to 25° C. The extreme maximum temperature for Hot Desert ranges from 43.5 to 49° C. Cold Deserts temperature in winter ranges from -2 to 4° C and in the summer 21 to 26° C a year.
Climatograph
This climatograph was measured in a hot desert. This shows how this biome gets very little rain in high temperatures. Summer months have the least amount of rainfall and the lowest temperatures. This shows how the most rainfall gotten in any month is 2 in or less, which is extremely scarce.
Animal Adaptations
Because of a lack of rainfall (and therefore vegetation), these animals need to be able to endure extreme temperatures and water scarcity (including the ability to obtain or fight for water)
All animals in the desert need the ability to survive extreme hot temperatures in hot deserts and extreme cold ones in cold deserts. In both cases, this usually means the ability to burrow to keep cool or warm, depending on the location and temperature. Tough , sand colored skin and spikes are defensive mechanisms. Some reptiles are colorful and venomous
1. Armadillo Lizard
All animals in the desert need the ability to survive extreme hot temperatures in hot deserts and extreme cold ones in cold deserts. In both cases, this usually means the ability to burrow to keep cool or warm, depending on the location and temperature. Tough , sand colored skin and spikes are defensive mechanisms. Some reptiles are colorful and venomous
1. Armadillo Lizard
2. Banded Gila Monster
3. Thorny Devil
4. Desert Bighorn Sheep
5. Desert Kangaroo rat
4. Desert Bighorn Sheep
5. Desert Kangaroo rat
Plant Adaptations
- Because of scarce rainfall, plants in the desert either need to be able to store large amounts of water and/or be able to go without water for long periods of time.
- These plants also need a special covering to reduce transpiration.
Some examples of desert plants:
1. Barrel catcus- this plant (pictured below) can store fairly large amounts of water and has long spikes for protection. Its skin soaks up water, but simitaneously helps it so the water doesn't transpire from the plant.
2. Saguaro Cactus (pictured below)- this tall cactus has 2 inch spikes on its vertical ribs, waxy skin, and ribbed patterns. These help it survive. When it rains, the ribs and waxy skin soak up the water to be used until it rains again. The spikes help protect it from thirsty/ hungry animals. The waxy skin also helps to minimize water loss through transpiration.
3. Creosote Bush
4. Joshua Tree
5. Pancake Prickly Pear Cactus
4. Joshua Tree
5. Pancake Prickly Pear Cactus
Keystone Species
The coyote is a top predator keystone species. It has a great impact on the ecosystem by controlling other populations.
Indicator Species -Desert Tortoise
This tortoise is very sensitive to changes in the environment. If anything is wrong with it (pollution poisoning, malnutrition, genetic defects) on a large scale, we know that something must be done.
K-Strategist -Bobcat
The average bobcat weighs 15 to 20 pounds, and is 2 feet tall and 3 to 4 feet long. They are content in the desert because of the bushy, and rocky terrain. The bushes give shade if it's hot, and the rocks are a perfect hiding spot if they're hunting prey.
The bobcat's diet consist of rabbits, squirrels, mice, gophers,rats, and fish. They're good at catching all their prey because of their hunting ability. Bobcats will have one litter of kittens a year. A litter of bobcats consists of 2 to 3 kittens. When a female has kittens, she will only hunt right around her den and not use all of her hunting territory. She will wean the kittens by three months and then bring back killed animals. Once they get used to eating meat, she brings them back live prey so they can practice hunting and killing. They will stay with the mother for almost one year, leaving in the spring. Bobcats live fairly decently long lives.
The bobcat's diet consist of rabbits, squirrels, mice, gophers,rats, and fish. They're good at catching all their prey because of their hunting ability. Bobcats will have one litter of kittens a year. A litter of bobcats consists of 2 to 3 kittens. When a female has kittens, she will only hunt right around her den and not use all of her hunting territory. She will wean the kittens by three months and then bring back killed animals. Once they get used to eating meat, she brings them back live prey so they can practice hunting and killing. They will stay with the mother for almost one year, leaving in the spring. Bobcats live fairly decently long lives.
R-Strategist- Sororan Desert Toad
It can get as large as 7 inches in size. Its rough skin helps it survive in a dry climate. It sings to attrach a mate. This toad can lay up to 8,000 eggs in one season. The eggs are placed in a pond and are left to hatch as tadpoles. They don't care for their young at all.
Environmental Problems/ Threats
Building in and around desert habitats compromises the health of desert wildlife. Also, increasing soil erosion by deforestation makes it so the soil is even less fertile. A loss of soil would be very bad in the desert.