AP BIO - Community/Ecosystem Ecology

Coevolution

The reciprocal evolutionary change between interacting species, where each species adapts in response to the other

Mimicry

An adaptation in which one species resembles another species to gain protection or a predatory advantage

Interspecific competition

A (-/-) interaction where individuals of different species compete for limited resources, reducing survival or reproduction

Ecological niche

The sum of a species’ use of biotic and abiotic resources; essentially its role in the ecosystem

Resource partitioning

The division of ecological niches that allows similar species to coexist by using resources in different ways

Commensalism

A (+/0) interaction where one species benefits and the other is neither helped nor harmed

Mutualism

A (+/+) interaction in which both species benefit from the relationship

Keystone species

A species that has a disproportionately large effect on community structure relative to its abundance

Ecological succession

The sequence of changes in community composition following a disturbance

Species richness

The number of different species present in a community

Relative abundance

The proportion of each species relative to the total number of individuals in a community

Trophic structure

The feeding relationships among organisms in a community, organized into trophic levels

Detritivores

Heterotrophs that obtain energy by consuming dead organic matter (detritus), such as fungi and bacteria

Net primary productivity

The amount of energy converted to biomass by producers minus the energy they use for respiration; represents energy available to consumers

Biomass

The total mass of living organisms in a given area or trophic level

Biological magnification

The increasing concentration of toxins in organisms at higher trophic levels in a food chain

Limiting nutrient

The nutrient that is in shortest supply relative to demand and therefore limits growth or production in an ecosystem

Food web

A network of interconnected food chains showing feeding relationships within a community

Turnover time

The rate at which nutrients or biomass are replaced in an ecosystem

Primary producers

Autotrophs that convert energy (usually sunlight) into chemical energy, forming the base of the food chain

Primary consumers

Herbivores that feed directly on primary producers