6.3.2: Populations and sustainabilty Flashcards
Carrying capacity
the maximum population size that can be maintained over a period of time in a particular habitat
Factors that limit population size
Abiotic • Water • Light • Oxygen • Nesting sites/shelter
Biotic
• Parasites
• Predators
• Competition for resources (both intra and interspecific)
Conservation
maintenance of biodiversity through human action or management e.g. controlled grazing, sustainable timber
Preservation
completely stopping human activity (no people allowed to enter area)
Reclamation
restoring ecosystems that have been damaged or destroyed; can include use of controlled burning of forest which can stop succession and increase biodiversity
Advantages of placing a species on the IUCN list
✔︎ Raise awareness
✔︎ Prevent extinction
✔︎ Wider effect of promoting more sustainable lifestyles
Disadvantages of placing a species on the IUCN list
✖️ 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
Economic arguments for conservation
✔︎ Ecosystems conduct valuable processes such as: nutrient cycling, cleaning water, providing an atmosphere, cleaning the air, food provision, provision of building materials, crop pollination
Social arguments for conservation
✔︎ Ecosystems provide pleasant environments with physical and psychological health benefits
Ethical arguments for conservation
✔︎ 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
1 preservation technique
Build a fence around an area to prevent humans entering
1 conservation technique
Allowed limited, carefully regulated, sustainable tourism to an area, and reinvest the profits to fund armed rangers to tackle poaching
What are sustainable resources?
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)
Sustainable timber production
- 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
Why is coppicing/rotational coppicing good for biodiversity?
- 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
Why is clear-felling bad?
- Destroys habitats on a large scale
* Soil erosion –> reduced soil nutrient levels
Why is overfishing bad?
Some populations are unable to regenerate so they will no longer be able to provide us with a food source in the future.
How can the problem of overfishing be overcome?
- 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
How can ecosystems be managed to balance conflict between conservation/preservation and human needs? (MASAI MARA)
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
How can ecosystems be managed to balance conflict between conservation/preservation and human needs? (TERAI REGION)
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
Peat bog
region of wet, spongy ground that contains decomposing vegetation; known as a “carbon sink” (store of carbon dioxide)
Challenges faced by peat bogs
- Pollution
* Acid rain (from neighbouring industrial powerhouses)
Why to conserve/preserve peat bogs
- to maintain biodiversity
- erosion control
- carbon storage
- flood management
Human activities that have caused the drying out of peat bogs
- Afforestation
- Peat extraction
- Agricultural intensification
How to conserve peat bogs:
- 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
