Community Development Flashcards
What are assembly rules and why are they important in determining community structure
Assembly rules state that history matters
The presence of species may increase or decrease the probability of occurrence of another species (not random)
The current configuration influences the future configuration
Define a small world network
There is where all of the nodes are not neighbours but are all connected by the smallest amount of links
A network where the proportional distance between any two randomly chosen nodes decreases as the number of nodes increases
In terms of network resilience Granovetter suggested that weak links are more important then strong strong ones
Because they connect the system where strong links can not (connect clusters of strong links)
Strong links are often redundant and therefore the loss of it compared to weak is less
The initial state of a community determines the tertiary state was the argument supported by?
Clements
At what stage of succession is species diversity greatest
In the middle because this is where there is a greatest abundance of both k and r species and therefore diversity is greatest
This is where community development and resource abundance are equal
Carrot cake is complicated whereas ecosystem is complex. Why
The carrot cake is complicated because it included many ingredients but we know the outcome of those ingredients and know would would happen if we removed one
Whereas an ecosystem is many components where we don’t know the outcome of them or what would happen if one was removed
Why is the ecosystem unpredictable where the cake is not
Because the ecosystem is a complex adaptive system (CAS)
CAS have the capacity to recognize the loss or addition of components through information processing and respond to the change through adaptation
In this area Garry Oak Ecosystems are described as culturally modified ecosystems. What does this mean in this course
Dominance in the landscape is in mid successional stage state and as such would transition to a more mature community, however it is rich in species important to local First Nations and so fire was used to stop the clock in succession and permanently maintain the availability of the Garry Oak Ecosystem
Clements
Communities are highly organized and persist over long periods of time which accumulates competitive interactions leading to a real equilibrium and community stability
Wrong
Clear, predictable, orderly
Climax community at balance
Diversity = stability
Gleason
Communities are the sum of independent species response to the environment over time. The community is not highly organized but is a random assemblage is species individually responding to environmental changes
Correct Individualistic concept Communities are accidents Interactions are amongst individuals Constant change
Succession
Sequential change in the relative abundance of dominant species in a community following disturbance
Energy/matter flow
Patch dynamics
Competition
Primary succession
Community develops from abiotic conditions
Sea level drop, glacier retreat, volcanic eruption
Secondary succession
Re development in a community from an early successional stage brought about by disturbance
Drought, Harvest, fire
Ramifications for ecological restoration
This means that the presence of one species or community does not mean it will reliably give rise to a predictable progression of future species/ communities
Important for food webs
The number of species and relative abundance important consideration
