Community development

EEB2244

succession

the process by which the composition of a community changes over time

seral stages

sequential phases of change during succession

pioneer species

the earliest species to arrive

climax community

final seral stage; composed of organisms that dominate a biome

succession: primary vs secondary

primary - has no plants or organic soil

secondary - organic soil via fire or hurricanes

primary succession

no plants or organic soil

secondary succession

organic soil via fires or hurricanes

patterns of succession

• small to large animals

• abiotic change, rapid to slow

• richness, rapid to slow

large-medium scale disturbances

fires, hurricanes

small scale distrubances

tree falls, animals

succession research: direct vs indirect

direct - experiments on occurring event

indirect - historical techniques

chrono sequencing

how old something is based on stage of succession

chrono sequencing is which type of succession research

indirect

limitations of chrono sequencing

assumes older sites pass through same stage as younger sites

early succession

R fast life history, many small seeds, widely dispersed, tolerates dryness not shade

What type of succession tolerates dryness? which tolerates shade?

early - dryness

late - shade

late succession

k slow life history, few large seeds, not widely dispersed, tolerates shade

mechanisms of succession

facilitation, inhibition, tolerance

mechanisms of succession: facilitation

early species have a positive impact on future species

mechanism of succession: inhibition

one specie has a negative impact on future species

mechanisms of succession: tolerance

tolerance to conditions increases chances of establishment