Succession Flashcards
What is succession?
The directional change in the structure of a community over time
What is each sequence of succession called?
A sere, or a seral stage
How is succession different from zonation?
Succession is in one location, zonation is across the landscape
What is the end stage of succession?
The climax community
Are changes during succession random or do they follow a predictable pattern?
Both, depends on the community
Who is the guy who came up with the relay floristics mechanism of succession? What is it?
Clements
Succession proceeds by predictable changes, inhibition, facilitation, and tolerance “pathways”
What is the facilitation “pathway” in relay floristics?
Early species facilitate the arrival of late species. Resident species don’t change the environment in any way that favours other species
What is the tolerance “pathway” in relay floristics?
Environment is unsuitable for early species, but neither favourable or unfavourable for late species. Resident species are the ones able to tolerate the conditions
What is the inhibition “pathway” in relay floristics?
Environment is less suitable for establishment by all species. Resident species inhibit the establishment of all other species
Who is the guy who came up with the initial floristics mechanism of succession? What is it?
Egler
What matters is who gets there first, if its pioneer species or species that survived the disturbance that reestablish
Who is the guy who came up with the idea that all successional changes are random?
Gleason
What are the 3 successional stages?
Early, mid, late
What species are in the early successional stages?
The pioneer community. Species with high growth rates, high dispersal, small size, potential for high population growth, r species
What species are in the late successional stages?
Species that are better at competition, lower dispersal, lower colonization, slower growth, longer lived, K species
What is primary succession?
Occurs on newly exposed substrates with no previous plant communities
What are the steps of primary succession? How long does it take?
- Rock weathering
- Soil formation from lichens and mosses that die, leave behind organic matter
- Successional stages
Hundreds of years
When does primary succession occur?
When no soil is initially present. Glacial retreat, volcanic rocks, sand dunes, etc
What is secondary succession?
Occurs on previously vegetated surfaces, with the first pioneer species already there
When does secondary succession occur?
After a disturbance, when soil is already present
What is the difference between primary and secondary succession?
The initial presence of soil
How do climax communities and pioneer communities differ in terms of seed dispersal?
Pioneer communities have wind dispersal, climax communities have animal dispersal
What are autogenic environmental changes?
Results from species within a community
What are allogenic environmental changes?
Results from physical environment
What drives succession in a terrestrial environment?
Species colonization and replacement
