Chapter 3.1 What is Ecology?

Interactions and Interdependence Ecology – the scientific study of interactions between organisms and between organisms and their environment (surroundings). The largest level in ecology is the biosphere – the portions of the Earth where life exists, including land, water, and air (atmosphere).

All organisms have interdependence on other organisms and the environment. There is not a single living creature that is not impacted by other organisms and the place where they live.

Levels of Organization Species – a group of similar organisms that can reproduce and produce fertile offspring. Example – horses, a good example of NOT the same species is when you breed a horse and a donkey you get a sterile (nonfertile) mule. Therefore, a horse and donkey are not the same species. Levels of Organization

Populations – groups or individuals that belong to the same species and live in the same area. Example – a wolf pack

Communities – Different population that live in the same area. Example - All of the living organisms that live in a forest, so all of the plants, the animals, and bacteria in that forest.

Ecosystem – all of the organisms that live in a particular area as well as the non-living, physical, environment. Example – the forest again but now take in all the rocks, weather, river (or water), fallen logs, and anything else that makes up the environment.

Biome – a group of ecosystems that have the same climate and similar dominant communities. Example – Marine biomes – all the salt water on Earth.

Ecological Methods Ecologists use 3 basic approaches for studying ecology: Observing – watching what is take place and asking questions. Experimenting – to test hypotheses. Can be in a lab or in the natural world. Modeling – models help to look at processes that happen over long periods of time. They are based on observation, experiments, and mathematical formulas.