•Cacti •Mesquite Tree •Desert Tortoise •Peccary •Meerkats
•Sand •Rocks •Small Hills •Hot Sun •Occasional Rain •Wind
The largest number of individuals of one species that an environment can support.
These are things that populations need to survive in the desert: Water,food,space,and shelter.
A population of desert tortoises live in rock shelters to escape the heat. Since they reproduce slowly,there more than likely won't be a lot of desert tortoises for a while. That effects the population because if their rock shelters were completely destroyed some how and they reproduce slowly,then that can create a a major decrease of desert tortoises.
Resources that limit the growth,abundance,or distribution of a population in an ecosystem.
Ex.Limited water supply,Sparce food,Hot weather,etc.
Predator/Prey Relationship In The Mojave Desert:
The Mountain Lion is the predator and the Mule Deer is the prey. Let's say that the limiting factor is sparce food. If the deer is looking for food and so is the mountain lion,then the affect of this happening would increase competition between the mountain lion and the deer.
These are things,like plants, that transform the sun's energy to energy that other organisms can consume.
Ex.Cacti,Shrubsan Grass,Sage Bush, and Succulent.
First Level Consumers:
These will be the organisms that eat the producers. Organisms who eat plants will usually be called herbivores.
Ex.Desert Tortoise,Mule Deer,Lubber Grasshopper,Jack Rabbit.
Second Level Consumers:
These organisms eat the first level consumers and are therefore the first set of carnivores.
Ex.Elf Owl,Roadrunner,Scorpion,Kit Fox.
Third Level Consumers:
These organisms eat the second level consumers and less energy is used with these animals.
Ex. Fennec Fox,Coyotes,Bobcats,Southern Grasshopper Mouse.
Producers are important...
Without producers to transform the sun's energy for us, then we wouldn't be able to get any food. (In other words we would die of starvation.)
Food Webs vs. Food Chains:
Food webs are more realistic because they actually show more possibilities of what a specific organism can eat. Food chains only show one specific organism to an ecosystem.
If I removed the Jack Rabbit, then the Coyote population would decrease as well would the Mountain Lion and the Mojave Rattlesnake. The up-side to this decrease of so many populations would be that the Cottontail and Chuckwalla population would increase.
Energy pyramids are shaped the way they are for a reason. If they were shaped like a cube or cylinder,the energy wouldn't be distributed correctly. The whole reason behind the pyramid is to show how the energy decreases as you go up the energy levels. If you didn't have the pyramid, then all the energy would be the same for each level of energy for each organism.
Why is it this way?
The producers are on the bottom of the energy pyramid because they have/store the most energy. The top predators are at the very top because they have/store the least amount of energy. This means that (since the sun gives the producers all the energy) the more energy an organism in an energy level takes in (or eats) the more energy they have.
Chemical equation for photosynthesis:
6CO2 + 6H2O ------> C6H12O6 + 6O2
Things needed for photosynthesis/What is produced by photosynthesis:
Water,Carbon dioxide,Sunlight,and the Chlorophyll in chloroplast.
Oxygen is produced by photosynthesis.
Where does this "photosynthesis" take place?
In the plant's cells in the chlorophyll that is in the chloroplast.
Tropisms are growth in response to certain stimuli like:water,light,touch,and gravity. There are four types of tropisms:
Tropisms in the desert consist of phototropism and gravitropism. Shown below are visual examples of these two tropisms.
Tropisms,like phototropism and gravitropism, are very helpful for a plant to survive in the desert. Phototropism helps the cactus get the sunlight it needs to grow. Gravitropism helps the Sage Bush (or other bushes in the desert) stay in the ground due to some very scarce windy days in the desert.
Decomposers are important to the desert because...they return ALL needed nutrients into the ecosystem for all the plants that need it! How cool is that!!
On the other hand,it wouldn't be so cool if they were gone. First off,the desert plants wouldn't have any nutrients to absorb from the ground because there would be no one/nothing to break down the needed nutrients. Second,the animals that eat those tasty desert plants,wouldn't have any food because the plants wouldn't have lasted as long enough for those animals to get food.
There are different types of decomposers in the desert. For example:
Adaptations are important because they help organisms survive and reproduce in certain changes of the environment. Adaptations can be structural or behavioral. A structural adaptation for a plant would be an onion bulb. A behavioral adaptation for an animal would be like a bird migrating to the south during the winter.
The adaptations that certain plants would need to survive in the desert would be like withstanding heat, kind of like a cactus. Cactus have adapted to the heat by having a physical structure called Xerophyte. Xerophyte helps conserve water within the plant.
Animals have a different way of adapting to the desert heat. They have many behavioral adaptations like searching for food at dawn to avoid extreme heat.
Have you ever wondered what would happen if you took a cactus out of the desert and placed it somewhere like the Artic? Well, let's just say that it wouldn't be pretty. The cactus is known for holding the limited water it absorbs for long periods of time. Cactus have grown very well in the desert. If the cactus were placed in the Arctic, then the cactus would absorb too much water and won't get very much sunlight to grow. If you've ever had a plant and gave it too much water and moved it out of the sunlight, the plants start to wilt. Overall ending in (sadly)-death.
The photo at the bottom shows the adaptations of the cactus and animals that have adapted to the desert heat.
Natural selection is when organisms are better adapted to their environment. Natural selection is really important for organisms in an ecosystem because it helps the organism survive and reproduce offspring.
The Rock Pocket mouse is a perfect example of natural selection in the desert. They now have a colored coat that protects them form predators. Dr.Michael Nachman created a lab for the mice and identified their genes involved in adaptation. Then there was a random change in the genome and it created a predator-proof coat. Now, the population of Rock Pocket mice has increased.