Ecosystems at Risk: Vulnerability and Resilience of Ecosystems Flashcards
what are the causes of ecosystem vulnerability
location
extent
linkages
biodiversity
the four following locational factors affect the functioning of ecosystems…
latitude
distance from sea
altitude
microclimatic features
true or false: The greater the degree of specialisation an organism has to a particular set of environmental conditions the more vulnerable that organism is to the changes in those conditions.
true
what does extent mean in relation to vulnerability
Ecosystems that are restricted to relatively small areas or have already been subject to extensive disturbance are especially vulnerable.
what does linkages mean in relation to vulnerability
Ecosystems that have high levels of interdependence are much more vulnerable to change.
eg. if an organism relies on one producer for survival, and that producer is wiped out, the consumer is at greater risk of being wiped out also
what is genetic biodiversity in relation to vulnerability
genetic diversity favours the survival of a species as it increases the chance that some members of the population will have the characteristics to be able to withstand changes in environmental conditions.
what is species biodiversity in relation to vulnerability
the greater the species diversity within an ecosystem the more able the ecosystem will be able to withstand threats.
what is ecosystem biodiversity in relation to vulnerability
the greater the number of habitats, biotic communities and ecological processes occurring, the easier it will be for the ecosystem to revoke from threats or changes in environmental conditions.
what are natural stresses in relation to vulnerability
stresses that the ecosystem that can withstand, as they are accommodated to the ecosystem. the ecosystem has pioneer species able to respond to the stress and rebuild
example of natural stresses
coral reefs are frequently damaged by tropical cyclones, but it has many pioneer species. Mangroves are also strong pioneer species.
what are human induced stresses
stress placed on ecosystems by humans
example of human induced stress
land-clearing and cropping, this creates a simplifies ecosystem and one encourages pests.
how can location make a system vulnerable
a species such as coral is adapted to shallow, nutrient-deficient waters. if there was an increase in nutrients in the water, algae growth is promoted, leading to a reduction of sunlight for coral growth.
or if the temperature increased in coral reef waters, it causes the coral polyp to die
define extent
size of an ecosystem
are ecosystems that overlap and rely on each other less vulnerable than smaller ecosystems with definitive boundaries
yes
define keystone species
an organism that helps define an entire ecosystem
what are the three levels of biodiversity
ecosystem, genetic and species
what effect does having more intertwined levels of biodiversity have on the vulnerability of an ecosystem
the more intertwined, the less vulnerabl
why does biodiversity decrease the vulnerability of an ecosystem
- a range of pathways for ecological processes
- if one pathway is destroyed, an alternative is found and the ecosystem continues to function as normal
why does biodiversity decrease the vulnerability of an ecosystem
- a range of pathways for ecological processes
- if one pathway is destroyed, an alternative is found and the ecosystem continues to function as normal
the greater the level of diversity =
greater oppurtunity to adapt to change
why does genetic diversity decrease the vulnerability of an ecosystem
organisms within the ecosystem having different characteristics means there is a larger chance of some of the organisms surviving a change
what is ecosystem diversity
the diversity within an ecosystem in terms of habitat differences, biotic communities and the variety of ecological processes
what is linkages also known as
interdependence
the greater the level of linkages/interdependence…
the greater the ecosystems ability to absorb change
eg. loss of a primary consumer from a food web is unlikely to have a major impact on secondary consumers due to range of alternative primary consumers.
the lower the level of linkages/interdependence…
much more vulnerable to change
eg. Krill are the dominant primary consumer organism and the main source of food/energy for some species of whales, with no intermediary stages in the food change. If there is a reduction of krill, it will directly impact the number of whales the ecosystem can support.
Under what conditions does long-term degradation occur?
Long-term ecosystem degradation occurs when the magnitude and duration of the stress exceed the ability of the component to repair itself.
list natural sources of catastrophic environmental stress
DROUGHT
FLOOD
FIRE
VOLCANIC ERUPTION
EARTHQUAKE
LANDSLIDE
CHANGE IN STREAM COURSE
DISEASE
list natural sources of gradual environmental stress
Natural climactic changes
Immigration/invasion of new species
Adaption/evolution
disease
what are the two types of stress
natural
human induced
what are the two rates of stress
gradual
catastrophic
what are the two magnitudes of stress
slight
extreme
what are some human induced causes of environmental degradation
population growth
poverty
debt
non-sustainable consumption
damaging waste
non-sustainable agricultural practices
exploitation of natural resources
how do humans modify energy flows and nutrient cycles
either removing or adding organisms or nutrients to an exosystem
what is an example of humans removing organisms and nutrients
hunting and traditional agricultural methods (without fertilisers)
what is an example of humans adding organisms and nutrients
introducing species and modern agricultural methods
how can humans modify relationships between biophysical components
they can modify how the spheres and natural processes interact.
eg. removing vegetation from an area can loosen soil, causing it to be washed away
eg2. restricting the amount of water that flows down a river, impacting organisms that live downstream
how do humans modify mount kosciuszko
land clearing for ski runs removes nutrients, and loosens top soil that will erode. the land clearing results in a loss of biodiversity
humans redirecting streams in mount kosciuszko alters the biophysical components
