What shapes an Ecosystem? 4.2

Biotic Factor• Biological influence on organisms within

an ecosystem.

Abiotic Factor• Physical, or nonliving, factor that shapes

an ecosystem.

Habitat • The area where an organism lives,

including the biotic and abiotic factors that affect it.

Niche

• Full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions.

Resource • Any necessity of life, such as water,

nutrients, light, food, or shape.

Competitive exclusion principle • Ecological rule that states that no two

species can occupy the same exact niche in the same habitat at the same time.

Predation• Interaction in which one organism

captures and feeds on another organism.

Symbiosis• Relationship in which two species live

closely together.

Mutualism• Symbiotic relationship in which both

species benefit from the relationship.

Commensalism• Symbiotic relationship in which one

member of the association benefits and the other is neither helped nor harmed.

Parasitism• Symbiotic relationship in which one

organism lives in or on another organism and consequently harms it.

Ecological Succession• Gradual change in living communities

that follows a disturbance.

Primary Succession • Succession that occurs on surfaces where

no soil exists.

Pioneer Species • First species to populate an area during

primary succession.

Secondary Succession• Succession following a disturbance that

destroys a community without destroying the soil.

Key Concept

• How do biotic and abiotic factors influence an ecosystem?–Together, biotic and abiotic factors

determine the survival and growth of an organism and the productivity of the ecosystem in which the organism lives.

Key Concept

• What interactions occur within communities?–Community interactions, such as

competition, predation, and various forms of symbiosis, can powerfully affect an ecosystem.

Key Concept

• What is ecological succession?–Gradual change in living communities

that follows a disturbance.