Chapter 5: How Ecosystems Work Vocabulary List

Food Web

a diagram that shows the feeding relationships between organisms in an ecosystem

Climax Community

a final, stable community in equilibrium with the environment

Ecological Succession

a gradual process of change and replacement in a community

Pioneer Species

a species that colonizes an uninhabited area and that starts an ecological cycle in which many other species become established

Consumer

an organism that eats other organisms or or organic matter instead of producers it own nutrients or obtaining nutrients from inorganic sources

Decomposer

an organism that feeds by breaking down organic matter from dead organisms; examples include bacteria and fungi

Nitrogen Fixing Bacteria

bacteria that convert atmospheric nitrogen into ammonia

Tropic Level

one of the steps in a food chain or food chain or food pyramid; examples include producers and primary, secondary, and tertiary consumers

Primary Succession

succession the beings in an area that previously did not support life

Phosphorus Cycle

the cyclic movement of the phosphorus in different chemical forms from the environment to organisms and then back to the environment

Carbon Cycle

the movement of carbon from the nonliving environment into living things and back

Food Chain

the pathway of energy transfer through various transfer various stages as a result of the feeding patters of a series organisms

Cellular Respiration

the process by which cells produce energy from carbohydrates; atmospheric oxygen combines with glucose to form water and carbon dioxide

Secondary Succession

the process by which one community replaces another community that has been partially or totally destroyed

Photosynthesis

the process by which plants, algae, and some bacteria use sunlight, carbon dioxide and water to produce

Nitrogen Cycle

the process in which nitrogen circulates among the air, soil, water, plants, and animals in an ecosystem