Sub 11: Succession Flashcards
what is succession?
progressive change in composition of communities from pioneer to climax
what does succession lead to an increase in?
species diversity
biomass
complexity of food webs
soil formation and water retention
name three types of succession
autogenic succession
allogenic succession
degradative succession
what is autogenic succession?
changes in the environmental conditions leading to changes in species composition in an ecosystem caused by the processes of the organisms themselves
what is primary succession?
plants become established on land not previously inhabited where no soil has yet been formed
why are the first colonisers lichens?
able to withstand desiccation and produce acids which begin to break down rock
what is secondary succession?
plants invade a habitat previously inhabited by other plants and has existing soil and organic material present
why does primary succession take longer than secondary
because soil has to first be formed to support communities
what is allogenic succession?
when the replacement of one community by another is caused by forces outside the plant community
what is degradative succession?
sequence of changes associated with decomposition processes
what is the other name for degradative succession?
heterotrophic succession
