Ecosystem Resilience Doc Notes Flashcards
Define Ecosystem Resilience
Refers to the capacity of an ecosystem to recover from disturbance or withstand ongoing pressures
Give an example of an ecosystem oftern under risk of vulnrability
E.g. Coral reef and other tropical marine ecosystems are subject to frequent disturbances, from threats such as cyclones, crown-of-thorns starfish outbreaks and influxes of freshwater as well as from a range of human activities. These events often damage, stress or kill components of the ecosystem.
What is a risiliant ecosystem able to do after a disturbance?
Given enough time, a resilient ecosystem will be able to fully recover from such disturbances and become as biodiverse and healthy as before the impact
Similarly, a resilient ecosystem may be able to absorb the stresses caused by these disturbances with little or no sign of degradation
What factors dose an ecosystem rely on to recover?
An ecosystem’s ability to absorb or recover from impacts, and its rate of recovery, depend on
Inherent biology and ecology of its component species or habitats
Condition of these individual components
Nature, severity and duration of the impacts
Degree to which potential impacts have been removed or reduced
What are the eatures on which to base an assessment of ecosystem resilience can be grouped as? (4 answers)
Key features on which to base an assessment of ecosystem resilience can be grouped as:
Ecosystem biodiversity
Ecosystem health
Impacts on the ecosystem
Projection and management
Define Ecosystem Biodiversity
The variation contained within species and between species and the condition of populations of species and their habitats can be a key factor in resilience
Define Functional Redundancy
The greater the biodiversity of an ecosystem, the greater the likelihood that an organism can perform a different ecological role when the ecosystem is under pressure
Shifts in an ecosystem’s biodiversity may indicate that the system is under pressure. Give an example of this.
E.g. a coral reef habitat with a diverse array of corals and fish and a relatively low abundance of fleshy algae usually indicates a habitat that is in relatively good condition. Pressures, such as overfishing, excess nutrients and ocean warming will often cause a long-term shift towards abundant algae and few corals (known as a phase shift).
What limits the rate in which a species is able to recover within an ecosystem?
The rate at which a species is able to recover within an ecosystem is limited by its biology and ecology
Outline ecosystem health
Natural functioning of an ecosystem’s physical, chemical and ecological processes is likely to result in a resilient ecosystem that can absorb stress and rebuild after disturbances.
Outline impacts on ecosystems
A number of factors affect ecosystems and in many ways, either individually or in combination and at various time and geographic scales.
Ouline chronic widespread impacts on ecosystem resiliance
Chronic widespread impacts (e.g. climate change) can seriously affect the resilience of an ecosystem
Ouline short-term local impacts on ecosystem resiliance
Even short-term local impacts (such as cyclones) can affect resilience, especially when acting in combination with other impacts
Outline the influence of impact frequancy
Impact frequency is also critical to resilience because an ecosystem will always require time to recover from an impact.
If recovery takes too long, or disturbances are too frequent or continual, the system may not fully recover before the next disturbance, leading to gradual, long-term degradation.
Why is protection and management important for an ecosystem at risk
For an ecosystem that is already under pressure, the effectiveness of protection and management measures at addressing the threats to that ecosystem is an important factor in retaining or restoring resilience.
