11.6 Factors Affecting Biodiversity

Question 1

What are the three main factors affecting biodiversity?

Answer 1

Human Population Growth, Agriculture, Climate Change

Question 2

How does human population growth affect biodiversity?

Answer 2

1. Habitat loss - Human development is destroying habitats, decreasing habitat biodiversity. Deforestation reduces number of species present in an area as it destroys their habitat
   eg. deforestation in the amazon to make way for agriculture
2. Over-exploitation - A greater demand for resources eg. food, energy means resources are being used up faster than they can be renewed, reducing genetic diversity in populations and decreasing species diversity
   eg. industrial fishing can deplete populations of certain fish and may cause extinction
3. Urbanisation - Sprawling cities and major road developments can isolate species, populations are unable to interbreed and genetic diversity is decreased
4. Pollution - High amounts of populates can kill species or destroy habitats, decreasing biodiversity
   eg. fertiliser flowing into rivers can decrease fish species

Question 3

Howe does agriculture affect biodiversity?

Answer 3

-To feed the growing number of people, large areas of land are devoted to monoculture which leads to a decline in global biodiversity as:
-Habitats are lost as land is cleared to make way for large fields, reducing habitat diversity
-Local and naturally occurring plants and animals are destroyed with pesticides and herbicides, reducing species diversity
-Heritage varieties of crops are lost because they don’t make enough money and so are not planted, reducing species diversity
-Removal of hedgerows to create space for agriculture and for large machinery, this reduces the number of plant species present and destroys the habitat of animals like insects and birds

Question 4

What is monoculture?

Answer 4

The growing of an single variety of a single crop

Question 5

What is climate change?

Answer 5

the variation in the earths climate

Question 6

How does climate change affect biodiversity?

Answer 6

-Most species need a particular environment to survive, climate change may mean that what was previously inhabitable becomes uninhabitable, causing a decrease of increase in a range of some species, which can decrease biodiversity in certain areas, and increase it in others
eg. The southern range limit of the Soot Cooper Butterfly has moved 60 miles north
-Some species will be forced to migrate to a more suitable area, causing a change in species disruption
-Plants cannot move, if the effects from climate change are too fast they will not be able to adapt and species may become extinct, reducing biodiversity
eg. Corals die if water temp changes by 1 or 2 degrees
-The melting of the polar ice caps could lead to the extinction of the few plant and animal species living in this area
-Rising sea levels from melting ice caps and thermal expansion could flood low-lying land, ruining habitats