6.3.2 Populations and sustainability Flashcards
What is population abundance/population size?
The number of individuals of one species in a particular area.
Depends on both abiotic and biotic factors.
How do abiotic factors affect population size?
Ideal abiotic conditions allow organisms to grow and reproduce successfully. Fluctuating conditions limit growth and reproduction.
What is interspecific competition?
Competition for the same resourced between different species
It means resources have to be shared between different specieso less available for both
What is intraspecific competition?
Competition for the same resouces between the same species.
How does intraspecific competition affect population size?
When resources are abundant, pop. size increases.
Increasing intraspecific competition
Causing pop. size to decrease
This pattern causes population numbers to fluctuate around the carrying capacity.
What is carrying capacity?
The maximum stable population size that an ecosystem can support.
How does predation affect population size?
When pop. size of prey increases, the pop. size of predator will increase
as more food is available
This will cause the pop. size of the prey to decrease due to overpredatation
Which in turn causes a decrease in predators.
What is conservation?
The management of ecosystems to allow sustainable use of resources, involving human interaction.
What is preservation and how is it different to conservation?
Preservation is the protection of ecosystems, minimising human impact.
Habitats are left alone and nothing is taken out.
What are the three main reasons for conservation?
- Economic
- Social
- Ethical
Why is conservation economically important?
-Natural areas attract tourists, bringing money to region
-High biodiversity ecosystems provide resources: drugs, food and building materials.
List 2 social reasons for conserving habitats
-Aesthetics
-Important for mental health
What is the ethical argument for conservation?
Humans have a moral responsibilty to prevent extinction, all species have the righ to live.
How can conservationists reduce conflict between human needs and conservation?
-Work with local communities to promote conservation awareness
-Reduce conflict between need and preserving biodiversity
List 6 ways that an woodland ecosystem can be conserved.
-Selecting felling
-Coppicing (can be rotational)
-Pollarding (a type of coppicing)
-Clearing trees in strips or patches
-Planting native trees
-Planting trees with plenty of space
What is coppicing and how does it help conserve a woodland?
Trees are cut close to the ground to encourage new growth
Stumps have good root systems, so they can grow quicker than saplings
What is pollarding?
A type of coppcing but the trees are cut higher up
This prevents deers from eating new shoots
Why is planting native trees better for conservation?
Better for biodiversity as they ahve established connections with other organisms in the ecosystem.
Why is spacing important when planting trees?
Prevents competition
Allowing maximal growth
Why is most fishing currently unsustainable?
More fish are being caught and killed than populations can replenish.
What are 2 sustainable fishing practices
-Fishing quotas
-Controlling mesh size
What is the purpose of fishing quotas?
Limits the number of fish that can be caught, preventing overfishing.
How does controlling mesh size in fishing nets help conservation?
Nets with larger holes will allow small by-catch
Young fish that are too small to sell can slip out of the net.
