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
