Community succession Flashcards
(26 cards)
Succession
the process by which the species composition of a community changes over time
Seral stage
each stage of community change during succession
Pioneer species
the earliest species to arrive at a site; typically are able to disperse long distances and arrive quickly at disturbed sites
Climax community
the final seral stage in the process of succession; generally composed of organisms that dominate in a given biome
what is the clearest way to record succession?
direct observation over time
Chronosequence
a sequence of communities that exist over time at a given location
Primary succession
the development of communities in habitats that are initially devoid of plants and organic soil, such as such dunes, lava flows, and bare rock
Secondary succession
the development of communities in disturbed habitats that contain no plants but still contain organic soil (e.g., ploughed fields, forests uprooted by a hurricane)
What does succession look like near Lake Michigan?
Different initial communities (aster, grasses, cattails) lead to a climax forest of beech and maple
What did studies in Glacier Bay and Duke Forest show?
They show how succession can vary and be studied using chronosequences and long-term data
How does plant succession affect animals?
Changes in plants alter habitats and thus animal communities
How does stream succession occur?
Rapidly, due to the downstream movement of organisms and frequent disturbances
What is the traditional model of lake succession?
Gradual infilling by plants and peat over time
What is an alternative model of lake succession?
Long periods of little change followed by rapid shifts during drought and reflooding
How does species richness change during succession?
It starts near zero, increases rapidly, then levels off or declines slightly
What traits do early-successional species have?
High dispersal, fast growth, early reproduction
What traits do late-successional species have?
Better competitive ability
What is facilitation?
One species increases the chance for another to establish
What is inhibition?
One species prevents another from establishing
What is the priority effect?
The order of species arrival affects future colonization
What is tolerance?
Species establishment depends on dispersal and persistence, not interactions
What did intertidal experiments with barnacles show?
Acorn barnacles inhibited earlier species and promoted algae growth
How do climax communities change?
Through time, size and type of dominant species can change
Give an example of climax community change
Oak-hickory forests transitioning to maple-beech dominance
