Lecture 12 Flashcards
What is a self-regulating ecological system?
An ecological system that has : self-sustaining ecological processes, ecological feedback loops, self-replacing populations and systems which exhibit ecological resilience
Where is resilience in the roller coaster diagram?
The length of the domain of attraction
What symbolizes stability in the roller coaster diagram?
The depth of the domain of attraction
What symbolizes the ecological community in the roller coaster diagram?
The ball
What is ecological resilience?
The capacity of a system to absorb disturbance and reorganize while undergoing change so as to still retain function, structure, identity and feedbacks
What is high biological diverisity associated with?
High ecological resilience
What are the views of nature?
Nature flat, nature balanced, nature anarchic, nature resilient
What is the nature flat view of nature?
System is stable only if forces are equal
management can control the system if the correct level of use is discovered
What is the nature balanced view of nature?
If disturbed, the system will return to equilibrium
management is for the maximum sustainable yeild. focused on constancy, efficiency, predictability and control
What is the nature anarchic view of nature?
The system is fundamentally unstable, and persistence is only possible with minimal demands to nature. Is focussed on maintenance of the status quo
What is the nature resilient view of nature?
There are multiple stable states
There is abrupt and transforming change. there is a need for understanding unpredictable dynamics, and management approaches are adaptive. Focused on variability, persistence, unpredictability and adaptiveness
What is adaptive management?
management that acknowledges uncertainty about how ecological systems and about how ecosystems respond to management actions.
However it isn’t a random trial and error process, it uses experimental design and competing hypotheses. Learning by doing
What is ecological resilience?
The capacity of a system to absorb disturbance and reorganize while undergoing change so as to still retain function, structure, identity and feedbacks
What is a threshold?
The place where a disturbance or change is more than an ecosystem can absorb and it shifts into another stable regime
What is hysteresis
The phenomenon when the state of the ecosystem lags behind changes in the effect that caused the initial change in the physical property. The system can jump rapidly to new stable state with only small change in conditions. However a much larger reverse change in conditions is needed to return the conditions to the original stable state
