AP®︎ Environmental Science: Topic 2.7 Flashcards

Gradual change in an ecosystem’s species composition and community structure as organisms colonize new habitat or a community recovers after disturbance

Succession beginning on a newly exposed or formed surface with little or no developed soil, so soil must form before most plants establish

Succession following a disturbance where soil remains, so recovery generally proceeds faster than primary succession

The first species to colonize an unoccupied or severely disturbed habitat; they tolerate harsh conditions and often modify the habitat for later species

The process by which early colonists modify a habitat in ways that make establishment by later species possible or more likely

The total mass of living material in an area; it generally increases during succession and eventually slows or levels off

The number of different species present; it generally rises during succession but may later level off, fluctuate, or decline

The rate at which producers store energy or biomass after producer respiration: NPP = GPP − R; it starts low, rises as producers establish, and may later stabilize or decline

A relatively stable late-successional community suited to local conditions, but not a permanent or inevitable endpoint

A species whose activities have a disproportionately large effect on community structure relative to its abundance or biomass

An organism whose presence, absence, abundance, condition, or chemical composition reveals an environmental condition or aspect of ecosystem quality