Ecosystem and their management Flashcards
Biophysical interactions which lead to diverse ecosystems
Ecosystem consists of fauna, flora & microorganisms & their abiotic environment.
Energy is passed through the trophic system -> productivity based upon food webs transfer of energy from trophic levels.
- Level 1 trophic/autotrophic: Sunflower
- Level 5 trophic (Apex predator)/heterotrophic: Lion
Atmosphere: main source of nutrients & affect functions of ecosystem due to climate change
Biosphere: consists of Autotrophic & heterotrophic species, transfers energy into life.
Hydrosphere: linked to Atmosphere as water moderates temp, damage the lithosphere due to coastal erosion.
Lithosphere: Provides habitats for decomposers & recycles nutrients
-> landforms and elevation affects species diversity.
Ecosystems functions
The function of an ecosystem is to store/capture energy, nutrients & water -> small fluctuations are magnified through the ecosystem
Oxygen & carbon: critical components for biotic things -> needed for photosynthesis & decomposition
Nitrogen cycle: Used by plants -> released back to atmosphere through decomposition.
Phosphorus cycle: Inorganic phosphorus consumed by plants through soil -> into organic phosphorus which is then intaked by the soil -> inorganic.
Water cycle: Continuous flow of water facilitates life which leads to higher biodiversity.
Vulnerability and resilience of ecosystems
Ecosystems ‘dynamic equilibrium’ interdependent of the sphere, makes them vulnerable -> temperature from atmosphere affects resilience -> growth of algae + agricultural runoff = coral bleaching in GBR.
Vulnerability can be caused by natural or human induced change
Higher biodiversity, linkage & larger area = greater elasticity / resilience. -> Daintree has small area
Catastrophic events succeed the amplitude of an ecosystem, which makes the biome malleable i.e after a cyclone.
Nearby human settlement makes ecosystems vulnerable, due to exploitation of ecosystem resources or deforestation.
Indirect Impacts due to human induced modifications
Further examples for indirect, although mentioning conservation indirectly would be enough for a response.
- Deepwater Horizon oil spill, 800,000 seabirds killed (2014)
- 1788, invasion of Australia: 100 plant species are extinct, 200 now endangered & 75% of rainforest cleared.
Impacts due to natural stress: Gradual
Climate change -> occurring over 100s of years
Ecological succession -> species immigrating & taking over due to environmental change -> affects food web.
-> Minnamurra rainforest, located near Kiama, experiencing non-endemic species (lantana), creating pockets of monoculture.
Adaptation -> species adapts to environment, amount of species grows -> places pressure on the pre-existing food web.
-> Japan Tosa Bay, tropical fish migrated in -> eating coral enabling for coral to colonise the area.
Impacts due to human induced modifications
Exploitation -> complete removal of natural vegitation that won’t come back -> absolute destruction of nutrient cycle, energy flow and biophysical relationship.
-> land clearing for urban settlement or extractive industries (coal mining)
Replacement -> removal of natural vegetation, replacing with foreign crops to create a monoculture, heavy strain on relationship and cycles
->Cotton farming on Murry Darling river, heavy use of water, disrupting the water cycle as the Murray Darling basin dries.
Utilisation -> Partial removal of natural vegetation which partly disrupts cycles and relationships, often is a modification of a natural environment.
->Pastoralism across the Illawarra, clearing of land in order to have room for cows -> large dairy industry in Berry.
Conservation -> Minimal damage to environment, purpose to maintain biome for scientific or conservation purposes -> no deliberate impacts but indirect impacts from surrounding areas can affect the environment.
-> GBR use of zoning and Heritage listing, but agricultural runoff leads to indirect damage to the salinity levels of coral reefs.
Impacts due to natural stress: Catastrophic
Changes that destroy the ecosystem and its function i.e droughts, fire, cyclones or eruptions.
1980 Mt St Helens eruptions = deforestation of coniferous forest, death of countless animals & blanketing of wildlife. However, regeneration has begun, with fauna & fauna + animals are transitory.
Cyclone Jasper 2024 exposing 20% of the reef to mechanical weathering of the waves
Direct Impacts due to human induced modifications
Sudden and dramatic = extinction,dynamic equilibrium is pushed past amplitude, disrupting energy flows & chemical cycles + reduction in species diversity.
- Deforestation of Amazon rainforest
- Overfishing in Great Barrier Reef
- Monoculture and fertilisers of Shoalhaven river
Measuring change
Hard to distinguish, gradual change of climate change, with no universal baseline
Benchmark - Current = Magnitude of change
Magnitude of change divided by time = rate of change
Intrinsic value:
Recognition of a biophysical environment provides inspirational, aesthetic and spiritual needs.
-> Blue mountain protection under NSW national parks
Recently, intrinsic values are respected, more educated about First Nations peoples, and a change of focus towards an ecocentric view.
-> Uluru - Climbing ban since 2019
Heritage value:
The Australian Heritage Commission determines natural Heritage sites. For ‘aesthetic, historic, social value’ -> protection for future generations.
-> GBR and DT are both on UNESCO Heritage list.
Education is important in developing public support for heritage listing. Mostly amongst GenZ.
Utility values:
The tangible an ecosystem can produce -> driven by anthropocentric view.
-> GBR contributes $6.4 billion annually to Australia’s economy and supports 64,000 jobs.
Loss of flora/fauna impacts humanity’s future source of food, medicine, and resources.
->EBC-46 element in cancer treatment found in flora/fauna.
Often leads to desertification of land
-> Coal resources are used to generate 75% of domestic electricity
Maintenance of Genetic diversity:
Greater genetic diversity = Greater survival/elasticity -> higher chance of environment surviving a stress as it has a reduced linkage.
Genetic loss by human expansion = primary driver of loss diversity.
-> Black-footed rock-wallabies of Barrow Island, WA, low levels of genetic diversity = suffering mortality and low fecundity.
Evolution extinction, one species a year, now loses 1 species a day, impact of humans.
Need to allow natural change to proceed
We must facilitate natural change to proceed
Human based sites Eg sanctuaries must be big enough to let natural processes continue
Buffer zone where human activity is carefully managed
Take interest in local people, who are reliant on the natural environment. Prevents exploitation
Sustainable development:
Intra-generational equity - Everyone has the right to benefit from the environment.
Intergenerational equity - present should be exploited, to save for future generations.
Precautionary approach -> taking measure to prevent irreversible damage
Biological diversity -> promote resilience in the environment.
Development need present generation to comprise, to protect future generation need (Brundtland Report) 1990
