Ecosystems

Photosynthesis Plants take in energy from the sun. Leaves take in carbon dioxide and give off oxygen as a by-product. Plants make glucose to use as food. Food that is stored is called starch. Roots take in water and nutrients from the soil.

Systems System: a group of parts that work together as a unit. A system has cycles and processes that interact, or affect each other. Open systems let things in and out Closed systems do not let anything in or out Over time a system will reach stability: changes in the system cancel each other out.

Parts of an Ecosystem Groups of living things and the environment they live in make up an ecosystem. A group of the same species living in the same place at the same time is a population. Several populations of different kinds can exist in one ecosystem.

Parts of an Ecosystem In most ecosystems, plants of the main population are where organisms interact. A community is made up of all the populations that live in the same area. Abiotic (nonliving) factors of an ecosystem interact with one another and with living things (biotic factors). Abiotic Factors include sunlight, soil, air, water, and temperature.

Biotic Factors in an Ecosystem Habitat: an environment that meets the needs of an organism Niche: role

Producers (Autotrophs): Make their own food (plants and algae) Consumers (Heterotrophs): Eat other living things (herbivores, carnivores, and omnivores) Decomposers: feed on the wastes of plants and animals or on their remains after they die, returning nutrients to the soil.

Energy Pyramid A diagram called an energy pyramid shows how much food energy is passed form one organism to another along a food chain.

Food Web

Changes in the Ecosystem Over time, changes in climate, rate of erosion, and populations can cause big changes in an ecosystem. Some changes, such as storms or changes caused by people, can change an ecosystem quickly.

Changes in the Ecosystem Succession: the process by which one community is replaced by another until a stable community occupied the area. A forest fire is an example of succession.

Changes in the Ecosystem Lichens and mosses will establish themselves in an ecosystem quickly. As plant and animal matter decomposes over time, nutrients are added back into the soil.

Repairing the Ecosystem

Preserving the Ecosystem Conservation: careful management and wise use of natural resources. Reduce: use less Reuse: use it again Recycle: make the old into new Redesign: change a product to use fewer resources to make it. Preservation: protection of an area