Biotic Factors: Living Factors in an Ecosystem

•jackal berry tree
•whistling thorn
•manketti tree

Abiotic Factors: Nonliving Factors in an Ecosystem

•very dry
•scarce water
•infertile soil

Carrying capacity- the most population an environment can support with it's resources

The resources that are necessary for survival are food, water, shelter, and space.

If the giraffes didn't have the leaves they needed, then there would be more competition and the giraffe population would decrease.

Limiting Factors- all of the factors that limit the growth of a population in a specific ecosystem

Some limiting factors in a savanna are extreme temperatures, and little rain.

A lion and a zebra are one example of a predator prey relationship. The limiting factors can prevent the growth of both populations.

Energy Levels

elephant grass->elephant->lion->African wild dog

Each energy role receives its energy from the level below it. Producers are vital to every ecosystem because they are the only ones who can take solar energy from the sun and transform it into something them and all other organisms can use.

Food webs are more realistic than food chains because in a food web, you can show many relationships between organisms and many different combinations of predator/prey relationships.

If you removed one population, the cheetah, for example, the other populations that the cheetah typically eats would grow too large and would be over populated, therefore causing all of the things that the cheetah's prey eats to become scarce, and everything else that also eats those things would become small in population and the predators of those animals would decrease in population. Removing even just one organism causes the collapse of the food web.

We use a pyramid shape, because it gets smaller as it goes up, which is representing the amount of energy in each level. Since the population uses about 90% of their accumulated energy, whatever eats them only gets 10% of their energy, which is why there are less animals at the top. The producers, which are on the bottom level, start with the most energy out of any level. The amount of energy received decreases as you go up the pyramid.



Photosynthesis requires radiant energy, water, and carbon dioxide, and the plant produces glucose and oxygen. Photosynthesis takes place within the plants chloroplasts. The energy transformation is the sun's radiant energy changed to chemical energy that the plant uses for food.


Tropism-turning or bending movement of an organism toward or away from an external stimulus, such as light, heat, or gravity. There are negative and positive tropisms.

Some tropisms that might occur in my ecosystem are geotropisms (gravity causing responses in a plant's growth), and phototropisms (the way a plant grows in response to light). These tropisms help plants in my ecosystem survive, because they allow the plant to get what it needs, such as light, and water, to survive.

Decomposers are vital to my ecosystem, because they decompose dead biotic things and transfer nutrients to the soil for other plants to reuse. Some decomposers in my ecosystem are, termites, bacteria, and fungi.



Adaptations are important because organisms need them to survive. The organisms specific to an ecosystem have adapted, or changed, to survive in that ecosystem. Some adaptation are opposable thumbs on a human hand, wings on a bird, and a cat's ability to jump. Some adaptations in my ecosystem are a gazelle running fast to evade a cheetah, and a tiger's stripes for camoflage.

If you placed an organism from my environment into another environment, the tundra for example, it would be unadapted to the cold weather, food and water sources, and predators.

Natural selection

Natural Selection- the changes, or adaptations, an organism makes to stay alive

The giraffes have long necks because they need to reach the tall trees for food. They have adapted this way to stay alive in their ecosystem.

Comment Stream

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3 years ago

@emmabarry thank you! I forgot to add pictures and I will add more abiotic factors.

3 years ago

nice work

3 years ago

@makennacarrick thank you! I'll add pictures soon!

3 years ago

@zacharycarpenter thank you for the feedback but I like my picture

3 years ago

@wadecoons thank you! and I'll add more pictures as soon as possible.

3 years ago

@matthewusreylopez thank you!!

3 years ago

Add a few more abiotic factors and see if you can find a more clear picture...yours is kinda blurry.

3 years ago

love your pictures!

3 years ago

great list of biotic factors

2 years ago

I like the nice detail and your energy pyramid, great job