biological communities

Limiting Factors• Any biotic or abiotic factor that restricts an

organism’s existence or reproduction

• Each species has a range of tolerance for each condition

Plants need everything in this barrel in order to grow. Which factor is limiting how much the plant can grow?

Succession= changes in a community over time

• Areas naturally change over time if left undisturbed

• Occurs in stages – takes a long time

• Primary succession: starts with bare rock– Pioneer species like lichens grow on the rock

and start to break it down into soil– Soil sits in crevices on rocks and small plants

start to grow there– Plant growth/death aids in breakdown of rock

to make more soil– Eventually results in a climax community

where little chance is taking place anymore

• Secondary succession: results from a natural disaster or from human activity– does not start with bare soil

• Some seeds still present, some species still living• Takes less time than primary succession