Levels of Ecological Organization

It is a great big complicated world out there! You can study the entire planet as a whole or study the habits of just a single organism. The levels of ecology put it all into context. The largest level is the biosphere, which includes everywhere life is found on Earth. With every level of ecology down from the biosphere, we zoom in and look at sequentially smaller and more specific parts of the world. The smallest level of ecology is an individual living thing; for example, just one single squirrel. The levels of ecology are like Russian nesting dolls, with each level fitting inside the next largest level.

BIOSPHERE: Everywhere life on Earth is found.

BIOME: A region defined by a specific climate (its temperature and precipitation) and certain types of animals and plants that have adapted to survive and thrive in that specific climate.

ECOSYSTEM: The interactions between all the living organisms and their nonliving environment in a certain place.

COMMUNITY: All of the living beings within an ecosystem, such as plants, fungi, animals, and bacteria. Does not include the air, dirt, water, or other nonliving things.

POPULATION: A group of individuals of the same species that live within the same community.

INDIVIDUAL: One specific living organism.

Biomes are simply a way to classify and describe general parts of the planet. Each biome is determined by its temperature and precipitation and the living things that have evolved in that climate. There are two main types of biomes: terrestrial and aquatic. Ecologists have further broken down those two types into more specific classifications. Biome maps can be divided up in many different ways and allow us to understand the similarities between places on opposite sides of the world.

CITIES—Although cities, towns, and suburbs are not considered biomes, humans have transformed the earth so much that we are now in a new geological era called the Anthropocene epoch.