10.3- SPECIES DIVERSITY AND HUMAN ACTIVITIES

Question 1

As natural ecosystems develop over time, what do they become?

Answer 1

complex communities with many individuals of a large number of different species

Question 2

What is the index of diversity like for natural ecosystems that develop into complex communities like?

Answer 2

high index of diversity

Question 3

What does farmers selecting species for particular qualities that make them more productive lead to?

Answer 3

number of species + genetic variety of alleles reduced to few that exhibit the desired features

Question 4

What follows if most of an area is taken up by one species that a farmer considers desirable?

Answer 4

there’s smaller area available for all the other species

Question 5

What happens to other species when there is a smaller area available for them?

Answer 5

compete for little spaces + resources available- many will not survive this competition

Question 6

Why are pesticides used to exclude unwanted species?

Answer 6

as they compete for light, mineral ions, water + food required by farmed species

Question 7

What is the index of species diversity like in agricultural ecosystems?

Answer 7

index of species diversity low

Question 8

What has helped increase food production in the UK?

Answer 8

improved genetic varieties of plant + animal species, greater use of chemical fertilisers + pesticides, greater use of biotechnology + changes in farm practices, leading to larger farms + conversion of land supporting natural communities into farmland

Question 9

Examples of practices that have directly removed habitats and reduced species diversity? (4)

Answer 9

removal of hedgerows + grubbing out woodland

creating monocultures, e.g. replacing natural meadows with cereal crops or grass for silage

filling in ponds + draining marsh/ wetland

over-grazing land- preventing regeneration of woodland

Question 10

Examples of practices that have a more indirect effect on reduced species diversity? (3)

Answer 10

use of pesticides + inorganic fertilisers

escape of effluent from silage stores + slurry tanks into water courses

absence of crop rotation + lack of intercropping or undersowing

Question 11

Conservation techniques- maintaining hedgerows at most beneficial height + shape

Answer 11

A-shape provides better habitats than rectangular one

Question 12

Conservation techniques- plant hedges

Answer 12

plant hedges rather than erect fences as field boundaries

Question 13

Conservation techniques- ponds

Answer 13

maintaining ponds + create new ones

Question 14

Conservation techniques- wet corners of fields

Answer 14

leaving wet corners of fields and not draining them out

Question 15

Conservation techniques- planting native trees

Answer 15

plant native trees with low species diversity rather than in species-rich areas

Question 16

Conservation techniques- reducing use of pesticides

Answer 16

use biological control where possible or genetically modified organisms that are resistant to pests

Question 17

Conservation techniques- type of fertiliser

Answer 17

use organic, rather than inorganic, fertilisers

Question 18

Conservation techniques- alternative to improving soil fertility

Answer 18

use crop rotation that includes nitrogen-fixing crop, rather than fertilisers, to improve soil fertility

Question 19

Conservation techniques- controlling weeds + other pests

Answer 19

use intercropping rather than herbicides to control weeds + other pests

Question 20

Conservation techniques- alternative to grass for silage

Answer 20

create natural meadows + use hay rather than grasses for silage

Question 21

Conservation techniques- when to cut verges + field edges?

Answer 21

leave cutting of verges + field edges until after flowering + when seeds have dispersed

Question 22

Conservation techniques- introducing conservation headlands

Answer 22

areas at edge of fields where pesticides used restrictively so wild flowers + insects can breed

Question 23

What can these conservation practices lead to?

Answer 23

food being slightly more expensive to produce

Question 24

What is in place as the conservation techniques will make food slightly more expensive to produce?

Answer 24

number of financial incentives from DEFRA + European Union

Question 25

Why is maintaining biodiversity important?

Answer 25

if biodiversity reduced, global living system becomes increasingly unstable + we all rely on global system for food + other resources