6.3.2: Populations and sustainabilty

Question 1

Carrying capacity

Answer 1

the maximum population size that can be maintained over a period of time in a particular habitat

Question 2

Factors that limit population size

Answer 2

Abiotic
• Water
• Light
• Oxygen
• Nesting sites/shelter

Biotic
• Parasites
• Predators
• Competition for resources (both intra and interspecific)

Question 3

Conservation

Answer 3

maintenance of biodiversity through human action or management e.g. controlled grazing, sustainable timber

Question 4

Preservation

Answer 4

completely stopping human activity (no people allowed to enter area)

Question 5

Reclamation

Answer 5

restoring ecosystems that have been damaged or destroyed; can include use of controlled burning of forest which can stop succession and increase biodiversity

Question 6

Advantages of placing a species on the IUCN list

Answer 6

✔︎ Raise awareness
✔︎ Prevent extinction
✔︎ Wider effect of promoting more sustainable lifestyles

Question 7

Disadvantages of placing a species on the IUCN list

Answer 7

✖️ Can only have a certain number of species on the list –> something must be kicked off
✖️ Stops locals using the land
✖️ Stops people accessing areas of natural beauty
✖️ Natural resources not available for use

Question 8

Economic arguments for conservation

Answer 8

✔︎ Ecosystems conduct valuable processes such as: nutrient cycling, cleaning water, providing an atmosphere, cleaning the air, food provision, provision of building materials, crop pollination

Question 9

Social arguments for conservation

Answer 9

✔︎ Ecosystems provide pleasant environments with physical and psychological health benefits

Question 10

Ethical arguments for conservation

Answer 10

✔︎ All organisms have the right to exist
✔︎ Humans have been responsible for the destruction of habitats/hunting of species to extinction - we now have a duty of care to conserve remaining ecosystems
✔︎ Humans have a moral responsibility to future generations

Question 11

1 preservation technique

Answer 11

Build a fence around an area to prevent humans entering

Question 12

1 conservation technique

Answer 12

Allowed limited, carefully regulated, sustainable tourism to an area, and reinvest the profits to fund armed rangers to tackle poaching

Question 13

What are sustainable resources?

Answer 13

Resources being economically exploited in a way that means they won’t run out OR the efficient use of finite resources so that they lost longer (e.g. recycling)

Question 14

Sustainable timber production

Answer 14

• Coppicing: cutting trunk of deciduous tree close to ground so new shoots grow; cut and cycle starts again.
• Rotational coppicing: cut 1 section of a wood each year, with some trees left to grow for longer to be harvested later for larger timbers.
• Pollarding: like coppicing, but cutting the tree higher up to prevent deer eating the shoots and preventing re-growth

Question 15

Why is coppicing/rotational coppicing good for biodiversity?

Answer 15

• Multiple habitats as different areas of woodland cut each year
• Trees never grow tall enough to block light and stop succession, so more species are able to survive

Question 16

Why is clear-felling bad?

Answer 16

• Destroys habitats on a large scale

* Soil erosion –> reduced soil nutrient levels

Question 17

Why is overfishing bad?

Answer 17

Some populations are unable to regenerate so they will no longer be able to provide us with a food source in the future.

Question 18

How can the problem of overfishing be overcome?

Answer 18

• International agreements on the numbers of fish that can be caught (e.g. Common Fisheries Policy, EU)
• Use of nets with different mesh sizes so immature fish can escape and grow to reproduce
• Allowing fishing only at certain times of year to allow breeding
• Fish farming

Question 19

How can ecosystems be managed to balance conflict between conservation/preservation and human needs? (MASAI MARA)

Answer 19

Masai Mara National Reserve (Kenya)
Aims and benefits:
• Ecotourism: infrastructure for local people as well as tourists
• Conservation programme to deter poachers
• Rangers provided with vehicles, weapons, communication equipment
• Ability to carry out research e.g. Michigan State University: behaviour and physiology of the hyena

Cons
✖️Loss of traditional culture
✖️ Water use & electricity demands rise
✖️ Changes to animal behaviour

Question 20

How can ecosystems be managed to balance conflict between conservation/preservation and human needs? (TERAI REGION)

Answer 20

Terai region, Nepal
• Due to fertile soil, high human population
• Industry and trade –> deforestation
• Locals rely on forest
• Aim to conserve land and wildlife and well as livelihood for local people whilst allowing economic development

Strategies
• Local community forestry groups set harvesting rules, set prices for products, decide how to reinvest profits

Successes
✔︎ Increased forest area
✔︎ Better soil and water management
✔︎ Higher employment rates
✔︎ Increased price of forest products

Question 21

Peat bog

Answer 21

region of wet, spongy ground that contains decomposing vegetation; known as a “carbon sink” (store of carbon dioxide)

Question 22

Challenges faced by peat bogs

Answer 22

• Pollution

* Acid rain (from neighbouring industrial powerhouses)

Question 23

Why to conserve/preserve peat bogs

Answer 23

• to maintain biodiversity
• erosion control
• carbon storage
• flood management

Question 24

Human activities that have caused the drying out of peat bogs

Answer 24

• Afforestation
• Peat extraction
• Agricultural intensification

Question 25

How to conserve peat bogs:

Answer 25

• Removal of seedlings from an area (trees have high water requirement, removing water from peatland)
• Use controlled grazing
• Ensure peat and vegetation on surface of it is as wet and undisturbed as possible