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Organisms and Their Environment

What is Ecology and Ecosystems

Ecology is basically the study of how organisms (animals, plants) interact with their ecosystem (their immediate surroundings), including living and non-living things in that ecosystem.

Ecosystems, is again, essentially just a word that means the "immediate environment" that an organisms lives in. Ecosystems include both living and non-living things.

Below you can see a picture of an ecosystem. It is an ecosystem because it includes "populations" of different "species" of animals, all interacting in one area. Maybe like a food web, where animals "interact" with one another by depending on the other as a source of food.

It's also considered an ecosystem, because as you can see at the top, it includes the sunlight, which is an abiotic factor (non-living factor).

Ecosystems Video

Okay, so I just Heard

Simple answer really.

Look at the roots of the words. "A" before any other word usually means "without". "Bio" we know means "life".

"A" + "Bio" = without life

Abiotic = non-living things in an environment or ecosystem
-ex: precipitation, temperature, soil, sunlight

Biotic = living things in an environment or ecosystem
-ex: predators, prey, parasites, plants, animals

Take a look at the picture below, then see if you can figure out the differences in abiotic vs biotic.

Abiotic vs. Biotic Video

Levels of Biological Organization

Levels of Organization in this part refers to how scientists/biologists/ecologists organize or name all the things in an ecosystem. It's actually very simple. Here's from least complex to the most complex:


SPCEB = Species --> Population --> Community --> Ecosystem --> Biosphere

OPCEB = Organism --> Population --> Community --> Ecosystem --> Biosphere

Organism and Species are essentially the same word.

Now to explain each.

A Species is a single organism. A Population is a group of organisms of the same species that can interbreed and produce fertile offspring. Organisms that aren't in the same population can't have fertile offspring (kids that can have kids). In other words, a cat and a dog can't be considered a population because they can't produce a normal kid. However, 2 dogs or 2 cats would be considered a population. A Community would be 2 different populations put together in the same place at the same time. Such as a group of zebra and a group of elephants that live in the same area of Africa. They would be considered a community. An Ecosystem is just the community plus the abiotic factors in that environment. So in other words, that same zebra and elephants, if you added in all the water, sunlight, soil, and temperature in that environment it would be called an "ecosystem". Simple, I know. And finally, the Biosphere is the entire sphere of life. Basically the earth.

Always remember, as you move left to right in those acronyms, its gets more and more complex because more animals and abiotic factors are involved.

Also, remember that a population is made up of a group of the same species, community made up of a group of different populations, ecosystem is made up of communities plus abiotic factors, and the biosphere is a big group of ecosystems combined. Read this while you're looking at "SPCEB" and it makes much more sense.

If not, take a look at the image below and you can see the big picture.....


Answer the following questions in the wiki comments section.

1. What is an ecosystem and what would be included in it?

2. What makes an ecosystem different from a community?