Biotic Factors

- Cacti

- Rattlesnakes

- Lizards (Ex. Texas Horned Lizard)

- Desert Toads (Ex. Sonoran Desert Toad)

- Scorpions

Abiotic Factors

- The soil located in deserts is mostly sand which allows little plant life to grow and contains little nutrients

- The temperatures in the deserts vary differently depending on the distance from the equator (closer deserts can go from 20-25 degrees Celsius)

- The amount of precipitation in deserts also vary (hotter, drier deserts receive about 10 inches of rain per year and colder deserts occasionally receive snow instead of rain)

Carrying Capacity and Changes in Population

Carrying Capacity- The limit of how many individual organisms an ecosystem can support

The resources that are needed include food, water, shelter, and space.

Limiting Factors and Predator/ Prey Relationships

Limiting Factors in deserts include disease outbreaks,

A predator/prey relationship in the desert can be between the Desert Coyote and the Pocket Mouse. A limiting factor that can affect them is is the mice become overpopulated and there is a disease spread among the majority of the population. Any coyote that eats the infected mice could receive the illness and spread it to coyotes also, which could make both populations drop.

Energy Roles

Producers- Organisms that can make their own food through photosynthesis (Ex. Cacti)

Consumers- Organisms that can't make their own food; must get energy from consuming other organisms. There is 4 types of consumers:

Herbivores are consumers that eat only plants (Ex. Desert Bighorn Sheep ).

Carnivores are consumers that eat only other animals (Ex. Rattlesnakes).

Omnivores are consumers that eat plants and animals (Ex. Coyotes).

Scavengers are consumers that eat dead animals.(Ex. Vultures).

Decomposers- Organisms that break down waste and dead organisms and turns them into nutrients (Ex. Dung Beetles).

The order that energy is transferred is from Producers-->Consumers( Herbivores--> Carnivores and Omnivores--> Scavengers) --> Decomposers

Producers play a major role in every ecosystem because they are the base for all food chains/webs.They are the only organisms capable to receive energy from the sun. Without producers all organisms would eventually go extinct.

Food Chains and Food Webs

Food webs are more realistic than food chains because

If one organism was removed from the food web (for this case my example will be rattlesnakes) all the organisms that it eats would become overpopulated and eventually eat all the producers. All those animals would lose their source of water and die off. Also any organisms that eats the rattlesnakes would eventually die off from starvation. Sooner or later, all the organisms would be extinct.

Trophic Levels and Energy Pyramids

Pyramids show that less energy is transferred the higher up an organism is in the ecosystem (

The most amount of energy available is at the base where the producers are. The amount of energy transferred gets lower the higher up on the pyramid which is why top predators are located ( receives least amount of energy).



Tropism- The turning or bending movement of an organism towards or away from an external stimulus.

Examples of tropisms in deserts include hydrotropism and

Hydrotropism can help plant in the desert survive because the roots go deeper into the earth allowing them to receive water from underground areas when there is no precipitation.

The Role of Decomposers

Decomposers are vital in deserts because there is already a lack of nutrients in sand and the nutrients they make helps the producers of deserts survive ( Ex. Cacti). An effect that there would be if there were no decomposers is that the producers would most likely die off and soon after, all other organisms would also become extinct.

Some decomposers that are located in deserts include dung beetles and bacteria ( there isn't many decomposers in deserts because most prefer to live in moist areas)


Natural Selection

Comment Stream

2 years ago

add pic for decomposers and youll be good