4.2- factors that affect biodiversity Flashcards
What does climate change mean?
Significant long-lasting changes in weather patterns.
What does monoculture mean?
A crop consisting of one strain of one species
Why does current estimate of biodiversity vary?
Current estimates of biodiversity vary, as it is impossible to know how many species currently in existence have not yet been discovered, what is certain is the number of species is declining and the genetic diversity of many species is also declining as a result of human activities.
How does human population affect biodiversity?
Several thousands ago, humans lived as hunters- gathers in small numbers and had little effect on natural processes. However, as the human population grows, and we demand more food and consumer goods, we have a greater and greater effect upon other species.
What have humans done to biodiversity?
-We have learned to use the environment to our advantages
- We alter ecosystems to provide ourselves with food.
-We destroy and fragment habitats
-We are using more of the earth’s resources
-We pollute the atmosphere.
As a result, our activities we often harm other species either directly or indirectly and this can lead to extinction.
How does agriculture affect biodiversity?
Agriculture has a huge effect on the biodiversity of natural habitats. As we clear natural vegetation, we reduce the sizes of habitats and the population of any wild species living in those habitats. This reduces genetic diversity of the species as their population is reduced. This means that the species has less capacity to adapt to changing conditions through evolution. It may also leave isolated and fragmented population that are too small to survive.
How does modern agriculture increase efficiency?
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Modern agriculture relies upon monoculture and selective breeding to increase efficiency. A monoculture is a crop consisting of one strain of the species- it has very limited genetic diversity. This makes the product easier to harvest
Give an example of monocultured product:
The oil palm, which is grown for palm oil. 85% of palm oil is produced in Indonesia and Malaysia. Rainforests with huge natural biodiversity are cut down at the rate of 150 hectares an hour. These are replaced by huge strands of a single strain of one species. Indonesia’s oil palm plantations already cover 9 million hectares, and this is set to rise to 26 million hectares by 2025.
How does selective breeding reduce biodiversity?
Selective breeding reduces genetic diversity as farmers select particular traits such as rapid growth or high protein content. Concentration on these characteristics means that other characteristic may be ignored altogether. A gain the genetic diversity of species declines
How does selective breeding risk species become rare?
Selecting for specific breeds of domesticated plants and animals means that other breeds become rare and may die out. Again, loss of these varieties reduces genetic diversity of species- this is known as genetic erosion.
How does human activities increase climate change and effect biodiversity?
Human activities appear to be altering the climate. Species that have lost their genetic diversity show less variation between individuals. As climate changes they are less able to adapt to the changes in temperature and rainfalls in the area they live in.
What is an alternative for species to avoid climate changes?
The only alternative will be for them to move and follow the climate patterns to which they are most suited. This will mean a slow migration of populations, communities and whole ecosystems towards the poles-plant currently growing in southern Europe may soon grow in northern Europe.
What might obstruct the migration of species?
- Major human development
- Agricultural land
- Large bodies of water
- Mountain ranges
Why are domesticated plants and animals at risk because of climate changes?
Domesticated plants and animals ate at risk. We have selectively bred our crops and animals to provide the best yield in specific conditions, which mean that they have little variation. As a result, our agriculture species are unlikely to be able to adapt to changing conditions and are vulnerable to disease. The efficiency of agriculture will decline, and less food will be available
What will farmers need to do about climate change?
Farmers will need to change the crops that they grow and the varieties of animals they keep. Crops form southern Europe may be grown in Britain, whole parts of southern Europe may become dessert.
