Desert

__ ﻿Deserts __

Location:

Abiotic Conditions: Deserts are defined by the factor that they receive less than 50cm of rain each year. The average temperature of deserts are about 20-25 degrees Celcius, but that number varies widely. At night, the temperature can drop to as low as -18 degrees Celcius and in extreme heat can reach upwards of 43 degrees Celcius due to the lack of insulation and bodies of water to keep a more consistent temperature. Soils are course-textured, shallow, rocky or gravely with good drainage and have no subsurface water. They are coarse because there is less chemical weathering, and the finer dust and sand particles are blown elsewhere, leaving heavier pieces behind.

Native Species: Deserts are home to plant species such as the Yucca plant, Sagebrush, and home to animal species like lizards, snakes, and burrowing owls.

Non-Native Species: Deserts have been infiltrated by such species as the Red Sesbania which has been introduced to the U.S. from South Africa. It reproduces fairly quickly and has been taking over and damaging fragile Riparian ecosystems in deserts. Another invasive species is the Mediterranean Steppe Grass because it is a good source of fuel for fires and has a a high drought resistant ability which prolongs its survivability rate and thus the chance of extreme and intense fires.

Indicator Species: The Joshua Tree is an indicator species in the Mojave Desert because it is dependent on the winter rains, and if the rains dont come or there is less than average the trees will be affected.

Keystone Species: Acorn Banksia is an example of keystone species because it is the sole source of nectar for honeyeaters, which play an important role in pollination of numerous plant species. Therefore the loss of this one species of tree would probably cause the honeyeater population to collapse, with profound implications for the entire ecosystem

Interspecies Competition avoidance: An example of Interspecies Competiton avoidance is the creosote bush which secretes a substance in its roots that keep other roots out of its feeding area.

Predator/Prey Relationship: An example of predator/prey relationship is a hawk in the desert searching for kangaroo mice hiding in the little bit of shade provided either behind rocks or underground.

Symbolic Relationship: A symbiotic relationship in the desert is that between the yucca moth and yucca plant (mutualism): the yucca moth is the only moth that pollinates the yucca plant, and the yucca plant is the only place a yucca moth will lay eggs.

Current Event: The Arabian Desert has entered a cold period where temperatures drop to about 10 degrees celcius and residents are warned to be properly dressed when going out at night. Deserts do not hold heat well because they are not well insulated, so the small desert towns are affected the worst. []

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