2.5 Zonation, succession and change in ecosystems

Zonation

The arrangement or patterning of communities or ecosystems in response to change, over a distance, in some environmental factor.

K-strategist (HL)

Species that usually concentrate their reproductive investment in a small number of offspring, thus increasing their survival rate and adapting them for living in long-term climax communities.

r-strategist (HL)

Species that tend to spread their reproductive investment among a large number of offspring so that they are well adapted to colonize new habitats rapidly and make opportunistic use of short-lived resources.

Plagioclimax (HL)

Interrupted succession, where disturbance can stop the process of succession so that the climax community is not reached.

Succession

The process of change over time in an ecosystem.

Seral stage

An intermediate stage found in ecological succession in an ecosystem advancing towards its climax community.

Sere

The set of communities that succeed one another over the course of succession at a given location.

Primary succession

The process of life that begins on a substrate that does not contain living organisms or soil. Examples are after a glacier retreats or a lava flow, where there is new, lifeless rock exposed. The process goes through a series of intermediate stages leading to a climax community.

Secondary succession

The process of life that begins with a biological footprint, such as soil and the organisms within it. It often occurs after a disturbance such as a forest fire or a recently clear-cut forest. The process goes through a series of intermediate stages leading to a climax community.

Kite Diagram

A diagram used to visualise the abundance and distribution of different species, using belt transect data