6.3.2 Populations and sustainability Flashcards
What is a population?
- All the organisms of one species in a habitat
What factors can control population sizes? Abiotic and Biotic
Abiotic:
- Temperature
- Light
- pH
- Water availability
Biotic:
- Predators
- Diseases
- Competition
- Immigration and Emigration
Intraspecific competition
- Competition between the same species
- Causes a cyclical change in the carrying capacity
- Populations increase when resources are high
- Populations decrease when resources are low
Interspecific competition
- Competition between different species
- Affect the populations for both species (lower)
- Affect the distribution of species
What is conservation and why do we do it?
- Protection and MANAGEMENT of an ecosystem so natural resources are still available
Economic: Maintaining biodiversity for drugs, clothes, and food.
Social: Enjoyment of natural habitat
Ethical: We shouldn’t exploit nature for our benefit
Ecological: Prevents climate change and natural disasters maintains food chain
What is preservation?
- Protection of an ecosystem and nothing is done to it
How can ecosystems be managed and provide resources in a sustainable way? (Fishing)
- Fishing quotas (EU) only allow for a fixed number of fish of a certain species to be caught from a particular area
- Mesh net sizes (smaller immature fish can escape allowing for breeding to continue)
- Fish farming to prevent the loss of wild species
- Recreation and commercial fishing at only certain times of the year to protect the breeding season of some fish
How can ecosystems be managed and provide resources in a sustainable way? (Timber)
- Rotational Coppicing (to maintain biodiversity)
- Pollarding (coppicing but higher up to prevent animals from eating the new shoots that appear)
- Selective cutting - removing only the largest trees
- Replanting trees (minerals and water cycle and biodiversity is maintained)
Role of peat bogs
- Store water
- Store Carbon dioxide
- Home to lots of different plants and animals
Things that cause problem sin PEAT BOGS
- Farm animals grazing causes loss of moss species and soil compaction
Preservation of peat bogs
- Environmental stewardship schemes give money to maintain peat bogs
- Lower number of livestock that use the peat bogs
Maasai Mara problems
- Cattle overgrazing can destroy grassland
- More grassland has been converted into cropland depleting nutrients in the soil
Massai Mara solutions
- Ecotourism means no exploitation of the natural environment
- Economic needs of the Maasai tribe are met while the environment is conserved
- Legal hunting to cull animals
Terai region of Nepal problems
- Areas of the forest are being destroyed for houses
- More conflict between humans and animals
- Elephants trample crops
- Tigers kill livestock
- Elephants and tigers can be killed because of this
Terai region solutions
- WWF provides solar generators and biogas generators
- Mint hedges to deter animals
