Predicting the Impact of Human Activities
Human activity has reduced biodiversity and had an impact on the magnitude, duration and speed of ecosystem change and there is an expectation of you being able to predict these impacts.
The human activities that feature in the extra guidance section are overexploitation, habitat destruction, monocultures and pollution. Other activities may include eutrophication, introduced species and pests, habitat fragmentation, building dams, use of pesticides/herbicides/fungicides, etc…
Overexploitation
Overexploitation means harvesting species or resources from the wild at rates faster than natural populations can recover. This includes overhunting and overfishing.
Habitat Destruction
Habitat destruction occurs when natural habitats are no longer able to support the species present, resulting in the displacement or destruction of its biodiversity.
Examples include harvesting fossil fuels, deforestation, dredging rivers, bottom trawling, urbanization, filling in wetlands and mowing fields.
Monocultures
Monoculture is the agricultural practice of producing or growing a single crop, plant, or livestock species, variety, or breed in a field or farming system at a time.
Planting the same crop in the same place each year removes nutrients from the earth and leaves soil weak and unable to support healthy plant growth, in addition to decreasing biodiversity.
Growing the same crop over a large area year after year is known as monoculture. Explain why an outbreak of pests is more of a problem in monoculture than where a mixture of crops is grown.
Pollution
All forms of pollution pose a serious threat to biodiversity, with issues affecting biodiversity in Australia generally being categorised as relatively local in nature (e.g. specific waste from poorly managed activities) or relating to broad landscape processes (e.g. nutrient enrichment in the Great Barrier Reef from farming or inappropriate pesticide use).
Explain how large-scale deforestation for agriculture would lead to a decrease in the diversity of organisms in the area.
Under natural and suitable conditions, bare soil would eventually become covered by a woodland community. Explain how farming practices prevent this from happening.