Biology Ecosystems notes Essay

A large amount of species in a small area Benches, rainforest’s canopies Medicinal value Most prescription drugs used were derived from living things Many lives have been saved from cancer by the rosy periwinkle tropical plant Penicillin comes from a fungus Agricultural value Wild plants serve a source of genetic variation Can provide biological pest contract reduces need of chemicals Wild bees resistant to mites that have wiped out honeybee population that pollinates crops Consumptive use Use of natural freshwater and marine ecosystems rather than aquaculture Wild fruits and vegetables, fibers, bees wax, seaweed are important economically Wood, rubber and latex are tree products of great economic importance. ‘Indirect’ ways of biodiversity value; 1 . Biochemical cycles- removal of excess nutrients, exploitation, pollution transportation. Heavy metals and pesticides that humans release 2.

Waste disposal- 3. Provision of fresh water- water cycle provides fresh water for terrestrial organisms- there is no substitute for fresh water- forests provide a ‘sponge effect’ by soaking up eater and reducing likelihood of flooding 4. Prevention of soil erosion- intact ecosystems naturally retain soil and prevent erosion 5. Regulation of climate- trees provide shade therefore less need for fans and air cons 6. Structures- tourists want to see natural beauty Restoration ecology 1. Best to begin as soon as possible before remaining fragments of habitat are lost 2. Use biological techniques that mimic natural processes to bring about restoration 3.

land salinity Changing the natural environment for agriculture Removal of trees and shrubs and replacing for short-rooted grass crops (wheat, barley etc. ) Deep rooted trees and shrubs tap into the water table deep down When they are replaced by crops, the water table rises bringing salt to the surface Enhanced greenhouse effect Increasing amount of greenhouse gases in atmosphere ca and methane are essential- they absorb infrared radiation and act as a thermal blanket for Earth Increased greenhouse gases= increased amount of trapped heat= increased surface temperature Coal burning (CA), deforestation and coal mining (methane) are all causes.

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Ozone depletion Caused by chlorofluorocarbons (CIFS) which are chemicals used as coolants- the CIFS escape and react with the ozone layer Ozone layer is vital in protecting from IV rays which cause melanomas and also chlorophyll degradation Habitat Loss Humans have caused some organisms to move or become extinct in that area by taking away the place where they live or the resources they need Habitat loss in tropical rainforest’s and coral reefs are particularly concerning because of the great perversity Loss of habitat also affects freshwater and marine biodiversity Alien species Animals and plant species introduced into Australia are categorized as alien species Some introductions have been intentional, others by ascend Some are pests that prey on native wildlife, bringing some near extinction Egg. Cats, foxes, goats, rabbits, pigs and cane toads Rabbits consume large amounts of vegetation preventing regeneration of many plant species. They also reduce the shade, shelter and food for native species. Goats compete with native herbivores Pigs destroy habitat along water courses

Pontification Process when non biodegradable chemicals build up in a food web Usually large predators most affected- they eat most of the prey which contain poisons Transportation Process whereby excessive levels of fertilizer are added to a waterway Causes rapid and uncontrolled growth of algae “algal bloom” The algae can have an extreme effect on all living things in a waterway- usually deprives the waterway of oxygen leading to the death of many species Sometimes algae creates a ‘screen’ on top of the water, preventing light for PHS to enter Aboriginal effects Use of fire created a grass and woodland ecosystem rather than large forests- giant marsupials extinct European effects- Slugs, snails, earwigs, rats, mice, camels, foxes, microorganisms, donkeys etc. Have often become pests, as they have no natural predators of effective competitors. Get limited results from shooting, poisoning, trapping etc. Maintain diversity- maintain energy flows in food webs, retaining good matter cycles, maintaining water quality Soil conservation- detritus and decomposer vital in an ecosystem Medicinal value- plant based cures/medicines

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