B2.1 habitat vs ecosystem, sustainability of ecosystems, tipping points Flashcards
ecosystem
Sustainable environment where geochemical cycles recycle nutrients for life (which support habitats, communities and populations)
what perspective is a habitat from
living organisms in terms of provision of its niche requirements for survival: light, nutrients water etc
what does an ecosystem focus on?
energy transfers, matter transformations, interactions between biotic and abiotic components.
are ecosystems open or closed systems
open. nutrients enter and leave through global geochemical cycles. this includes inputs of pollutants & toxins or loss of resources
sustainability broad definition
The ability to provide for current needs whilst maintaining enough resources for future generations.
ess specific sustainability
- constant recycling of matter means there should always be enough nutrients and water etc to sustain the current climax community.
- maintained by biotic factors such as consumers and decomposers.
tipping point
- a point where the extent of environmental change leads to the collapse of the original ecosystem and development of a new equilibrium.
- would never naturally be able to go back to the original climax community.
example of tipping point
extensive deforestation in the amazon = less transpiration = less rain = desertification
example of a self sustaining ecosystem
rainforests
keystone species
have a disproportionate effect on the ecosystem
eg of ecosystem engineers
elephants & beevers
eg of bottom-up species
bees
eg of top down species
wolves and starfish
the removal of keystone species can lead to….
tipping points in the ecosystem
carrion
dead animals
difference between anthropocentric approach and ecocentric
anthropocentric = making humans do it through laws, tax, education
ecocentric = i do it myself
what 9 aspects does the Planetary Boundaries Model take into account?
- climate change
- novel entries
- ozone
- aerosols
- ocean acidification
- biochemical flows
- freshwater use
- land use
- biosphere integrity
does does the PBM show
effects of anthroposphere on a sustainable ecosystem - biosphere
conservation
to restore something to its original form. fixing
preservation
keeping something how it is
background extinction rate value
we are meant to lose 1 species per million a year
what does the background extinction rate show?
natural rate of extinction that occurs through normal rates of environmental change & evolution
what is our current extinction rate estimated to be?
100- times higher. anywhere between 200-2000 species per year
