To Put It Dryly: The Desert
Vaidehi Phirke, Britney Le, & Jeena Yoon
Ladies and gentlemen, we present to you... the desert biome!
The desert biome encompasses around 20% of Earth's surface, occurring where precipitation is less than 25 cm per year. Deserts are characterized by their dryness. Terrain ranges from flat with dunes to mountainous and rocky. The flora and fauna are specialized for the environment, including the scarce rainfall, extreme weather differences from day to night, and the occasional fire/cold weather/flooding caused by sudden heavy rains. There are four main types of deserts: Hot and Dry, Semiarid, Coastal, and Cold, and we will look at each of these throughout this Smore.
Plants of the Desert Biome: ADAPTATIONS
Many plants have thick, waxy skin to prevent water loss, such as various cacti.
Reduced leaves, in form of spines, decreases surface area for transpiration. Spines also protect the plant from predators.
Some plants, such as mesquite, utilize a root system that absorbs water from the water table.
Certain plants also have heat- and drought-resistant seeds.
Some seeds can remain dormant for 50 years, until they receive water.
- Flowering desert plants take advantage when there is water and quickly mature and produce flowers and seeds.
- Succulents store water in fleshy parts within them.
ANimals of the Desert Biome: ADAPTATIONS
Camel species store fat in their humps, and use it when food is scarce.
Some animal species have adapted to use their own respiration to obtain water.
- Many desert animals are small, meaning they need less food, water, and can use the smaller shrubs as shelter.
- Animals species in the desert also excrete concentrated urine, preventing further water loss.
- In order to avoid the soaring temperatures, many species have adapted to being nocturnal.
- Certain species also undergo estivation.
- Many smaller species utilize camouflage.
Symbiotic Relationships in the Desert Biome
Predation: Coyote preys on a whitethroat woodrat.
Mutualism: Desert bees and cacti depend on each for food and nectar and a source of pollination, respectively.
Commensalism - The cactus wren builds its nest in the Cholla cactus, providing its young with shelter and protection. The cacti do not benefit nor are harmed.
Parasitism - Wasps lay their eggs inside the eggs of praying mantis eggs. When the wasps hatch, they feed on the mantis larvae and make their way out of the egg.
Competition - The coyote & sidewinder rattle snake both compete for the same food sources.
Primary Succession in the Desert!
Stone that has been weathered is invaded by bacteria & seeds of colonizing species.
The seeds have put down roots, breaking down rock and stabilizing the topsoil. Bacteria has been at work in breaking down the rock as well.
With the advanced soil, newer species such as grasses and small shrubs are able to survive with the presence of water.
Interesting facts about the desert!
- Some deserts can get so hot, rainfall evaporates before it even touches the ground!
- The two hottest temperatures ever to be recorded on Earth were found in deserts: 136°F on the edge of the Sahara desert, and 134°F in Death Valley, within the Mojave Desert.
- 'Sahara' in Arabic means 'desert', so whenever we say Sahara Desert, we're saying Desert Desert.
- In 6 hours, the world's deserts receive more energy (from the sun) than humans consume in a year.