What lives in the forest?
Take a close look at this ecosystem. Obviously there are deer and many types of plants. But there are organisms that live there that cannot be seen in the picture. Many other animals, such as rabbits, mice, and countless insects. There are also bacteria and fungi. Add in the nonliving aspects of the area, such as the water, and you have an ecosystem.
The Ecosystem
Ecology is the study of how living things interact with each other and with their environment. It is a major branch of biology, but has areas of overlap with geography, geology, climatology, and other sciences. The study of ecology begins with two fundamental concepts: the ecosystem and their organisms.
Organisms are individual living things. Despite their tremendous diversity, all organisms have the same basic needs: energy and matter. These must be obtained from the environment. Organisms depend on and are influenced by their environment. The environment includes two types of factors: abiotic and biotic.
- Abiotic factors are the nonliving aspects of the environment. They include factors such as sunlight, soil, temperature, and water.
- Biotic factors are the living aspects of the environment. They consist of other organisms, including members of the same and different species.
An ecosystem is a unit of nature and the focus of study in ecology. It consists of all the biotic and abiotic factors in an area and their interactions. Ecosystems can vary in size. A lake could be considered an ecosystem. So could a dead log on a forest floor. Both the lake and log contain a variety of species that interact with each other and with abiotic factors. Another example of an ecosystem is pictured below .
A desert ecosystem. What are some of the biotic and abiotic factors in this desert ecosystem?
When it comes to energy, ecosystems are not closed. They need constant inputs of energy. Most ecosystems get energy from sunlight. A small minority get energy from chemical compounds. Unlike energy, matter is not constantly added to ecosystems. Instead, it is recycled. Water and elements such as carbon and nitrogen are used over and over again.
Habitat
The habitat is the physical environment in which a species lives and to which it is adapted. A habitat’s features are determined mainly by abiotic factors such as temperature and rainfall. These factors also influence the traits of the organisms that live there.
Summary
- Ecology is the study of how living things interact with each other and with their environment.
- The environment includes abiotic (nonliving) and biotic (living) factors.
- An ecosystem consists of all the biotic and abiotic factors in an area and their interactions.
- A habitat is the physical environment in which a species lives and to which it is adapted.
CK-12 Foundation, Life Science. http://creativecommons.org/licenses/by-nc-sa/3.0/
