Populations and Ecosystems

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What is a population? A population is all the individual organisms found in a given habitat, of one species. So you could talk about a population of wolves in the woods. If you want to talk about the wolves and rabbits in the woods, then you'd be referring to a community. A community is made up of the various populations in a habitat. So the summation of all the living things in a given area is called a community. What then is an ecosystem?

An ecosystem comprises the community of living organisms in a habitat, together with all the non-living components such as water, soil, temperature, etc. called abiotic factors.

Why are different organisms of different species able to coexist in the same habitat? How come they don't directly compete with one another and drive others out? Have a watch...

So that's the last and loveliest new term: niche. It rhymes with quiche. A niche is the interaction, or way of life, of a species, population or individual in relation to all others within an ecosystem. It's how it behaves, what it eats, how it reproduces, where it sleeps, etc.; a species' niche is determined by both biotic factors (such as competition and predation) and abiotic factors.