Ecosystems Notes

Ecology - the study of interactions between organisms and between organisms and their environment.

The study of all living things would be a huge task so we break things down into smaller pieces.

1.         Species - a group of organisms so similar to one another that they can breed and produce fertile offspring. e.g., one single mosquito

2.         Population - a group of individuals that belong to the same species and live in the same area. e.g., all the crows in an area

3.         Community - a group of several populations living in a defined area. e.g., all the ducks, frogs, and water lillies

4.         Ecosystem - a group of organisms living together and their environment. Natural ecosystems are self-sustaining. All they need is sunlight and a source of water. All other matter in an ecosystem is recycled. Ecosystems have two parts:

            a.         biotic - all living things in the ecosystem. e.g., plants, animals, bacteria

            b.         abiotic - all nonliving things in the ecosystem. e.g., rocks, weather, temperature

5.         Biome - a group of ecosystems that have the same climate. Climate is the long term pattern of temperature range and precipitation. Remember that weather describes the day to day conditions while climate refers to the long term expectations.

6.         Biosphere - the thin layer of the planet which supports life. The biosphere consists of three parts

            a.         lithosphere - all the land

            b.         hydrosphere - all the water

            c.         atmosphere - all the air

Every organism has it’s own special needs. The habitat is the place where the organism prefers to live. A good habitat provides several things:

            a.         food - an organism must have a constant supply of food nearby

            b.         water - many species cannot live very long without water

            c.         living space - many species require a certain amount of space to thrive

            d.         protection from predators and weather - organisms must be able to find shelter