Populations and Sustainability 6.3.2

Question 1

factors that determine the size of a population

Answer 1

Limiting

• abiotic
• • temp
• • light
• • pH
• • water availab.
• biotic
• • predators
• • disease
• • competition

Migration

• immigration
• emigration

Question 2

carrying capacity

Answer 2

the max population size that an environment can support

pop size remains relatively stable, births ≈ deaths

Question 3

density independent factors

Answer 3

factors that have an effect on the whole population regardless of its size

eg. earthquakes, fires

Question 4

interspecific competition

Answer 4

competition between different species for the same resource

results in reduction of resource available to both species, and one species going extinct (competitive exclusion principle)

Question 5

intraspecific competition

Answer 5

competition between individuals of the same species

results in fluctuations in the no. organisms present in a particular pop. around the carrying capacity

Question 6

competitive exclusion principle

Answer 6

if two species are competing for the same finite resource, the less well adapted species is likely to be outcompeted

Question 7

what’s the difference between conservation and preservation?

Answer 7

conservation involves human action to help maintain biodiversity, while preservation restricts or bans human interferance

Question 8

conservation

Answer 8

maintenance of biodiversity through human action or management so that the natural resources in them can be used without running out

includes ecosystem management and reclamation

dynamic

Question 9

preservation

Answer 9

protection of an area by restricting or banning human interference, to keep the ecosystem in its original state

Question 10

why is conservation important?

Answer 10

Economic
- ecosystems provide lots of valuable resources eg. rainforests provide medicines, clothes, and food which can be traded locally and globally

Social
- aesthetic reasons, relaxation and exercise

Ethical

• all organisms have the right to exist, not our choice to decide if they live or die
• moral responsibility to future generations

Question 11

coppicing

Answer 11

tree trunk is cut close to the ground, and new shoots form from cut

Question 12

rotational coppicing

Answer 12

woodland is divided into sections and trees are only cut in a section until all have been coppiced. then you move to another section while the trees groow

maintains biodiversity as the trees never grow enough to block out light, so succession does not occur

Question 13

pollarding

Answer 13

tree trunk is cut higher up that in coppicing so deer and other animals can’t eat the shoots

Question 14

how can companies make sure large scale timber felling is sustainable?

Answer 14

• selective cutting (only removing largest trees)
• replanting
• plant far apart to reduce competition
• manage pests and pathogens
• leave areas of forest for indigenous ppl

Question 15

how is sustainable fishing done?

Answer 15

• Common Fisheries Policy (EU) puts limits on no. fish that can be caught in diff areas
• nets with diff mesh sizes to allow young fish to escape
• limit to certain times of year
• fish farming

Question 16

How is the Masai Mara managed to balance the conflict between conservation/preservation and human needs?

Answer 16

Traditional grazing and cultivation has led to removal of vegetation and increased soil erosion = reliance on fertilisers

Masai people being encouraged to make money from Ecotourism which supports conservation and local communities

Poaching has also been discouraged (laws, deterrents), saving black rhino

Question 17

How is the Terai region of Nepal managed to balance the conflict between conservation/preservation and human needs?

Answer 17

Large areas of forest have been cleared, which increases the effects of monsoon flooding and damages wildlife

• improved irrigation
• growth of nitrogen fixing crop to improve soil quality
• provide ppl with solar heaters to reduce reliance on wood for fuel

Question 18

How are peat bogs managed to balance the conflict between conservation/preservation and human needs?

Answer 18

Bogs are very acidic and water logged (anaerobic). They act as carbon sinks and are home to many different plants (lots of Sphagnum moss). Also help control floods.

Peat is used as a fuel which releases CO2 and damages ecosystems. Also used by farmers to improve soil acidity.

• ditches to allow water run off
• removal of seedling trees from area
• controlled grazing

Question 19

the effects of human activities on the Galapagos Islands

Answer 19

• giant tortoise was hunted to extinction for food
• non-native plants and animals have been introduced which have affected native species
• fishing has affected sea life
• tourism has led to development, which has damaged the ecosystem
• eradication has removed non-native species like wild dogs
• marine protected area established around the islands which puts limits on fishing
• you cannot visit the islands without a lisensed guide

Question 20

the effects of human activities on Antarctica

Answer 20

• seal hunting
• sewage dumping
• fishing
• oil spills
• The Antarctic Treaty
• commercial whaling and seal hunting banned
• limits on fishing
• all waste taken away by ship for disposal abroad
• tourist restrictions

Question 21

the effects of human activities on Snowdonia and the Lake District

Answer 21

• footpath erosion from tourism
• vegetation is trampled
• water pollution
• conservation charities undergo repair work
• walkers told to not take shortcuts which increase erosion
• improved sewage treatment

Question 22

explain why the reintroduction of wolves into the yellowstone national park is an eg. of conservation (2)

Answer 22

1 restoring the ecosystem (to its original form)
or
 maintains biodiversity ;
2 helps the (global) wolf population ;
3 active / dynamic / sustainable,
 management / maintenance ;
4 prevents over-population by the elk ;
5 prevents over-grazing
or
 damage to, habitat / ecosystem ;