[10.3] species diversity and human activity

Question 1

why is biodiversity important?

Answer 1

a great biodiversity increases the stability of ecosystems by reducing how much one species relies on another for food and shelter

Question 2

why do humans need high biodiversity?

Answer 2

1. medical / pharmaceutical uses
2. commercial products
3. tourism
4. agriculture

Question 3

monocultures:

1. what does it involve?
2. how does it reduce biodiversity?
3. what is an alternative method?

Answer 3

1. growing only one crop type allows for large amounts to be produced and more profit
2. smaller space available for other species, all crops susceptible to same disease, fewer niches for animals and limited resources
3. crop rotation

Question 4

pesticides and herbicides:

1. what does it involve?
2. how does it reduce biodiversity?
3. what is an alternative method?

Answer 4

1. spraying chemicals to destroy insect species (pesticides) and wild plant species (herbicides) - crops are competing less for light, space, water and mineral ions
2. removal of insect and plant species, reduction in food for other species
3. GM pesticide resistant crops, leave conservation areas of the fields where pesticides are used sparingly

Question 5

fertilisers:

1. what does it involve?
2. how does it reduce biodiversity?
3. what is an alternative method?

Answer 5

1. adding natural or artificial substances to supplement the nutrients available for the plant
2. surface run off can lead to eutrophication and loss of plant and animal life in ponds
3. crop rotation involving a nitrogen fixing crop, which put nutrients back into soil

Question 6

loss of hedgerows:

1. what does it involve?
2. how does it reduce biodiversity?
3. what is an alternative method?

Answer 6

1. conversion to agricultural land so there is more space to grow crops
2. loss of habitats and food sources for insects, hedgerows act as a safety corridor between woodlands
3. conservation headlands - areas around the perimeter of fields in which pesticides are not sprayed and nothing is harvested

Question 7

filling in ponds and wetlands:

1. what does it involve?
2. how does it reduce biodiversity?
3. what is an alternative method?

Answer 7

1. conversion to agricultural land and drainage of wetlands
2. removal of habitat
3. leave ponds and wetlands wild, leave wet corners of fields

Question 8

overgrazing:

1. what does it involve?
2. how does it reduce biodiversity?
3. what is an alternative method?

Answer 8

1. expanding the time / space grazing animals are left to feed
2. prevents regeneration of woodland leading to habitat loss
3. protected non-grazing zones

Question 9

deforestation:

1. what does it involve?
2. how does it reduce biodiversity?
3. what is an alternative method?

Answer 9

1. cleaning natural woodland for agricultural land
2. removes habitats, removes nitrogen and carbon from that location, contain complex food webs with high diversity
3. protected areas of woodland, plant native trees in areas of low species diversity

Question 10

what are some examples of conservation schemes? (6)

Answer 10

• fishing ban in certain areas
• limit on boat use over the coral reef
• legal protection to endangered species
• culling (controlling of species population to prevent overpopulation
• creating protected areas such as SSSI’s (sites of species scientific interest) and AONBs (areas of outstanding natural beauty)
• the environmental steward scheme encourages farmers to conserve biodiversity eg. replanting hedgerows, leaving margins around fields for wild things to grow