Populations and Sustainability Flashcards
What abitotic factors affect population size?
Abiotic - temp oxygen, CO2, light intensity, pH and soil conditions. The less harsh, the larger the range of species as they undergo less selection pressures which lead to natural selection.
What Biotic factors affect population size?
Biotic - interspecific and intraspecific (between individuals of the same species) competition, predation.
Inter - competition for food, water and habitat.
Intra - competition for mates AND resources
What is conservation?
Human actions and management to help maintain biodiversity. It involves sustainable development where ecosystems are managed so humans can use natural resources without them running out.
What is preservation?
Protecting an area by banning visitors. Effective for protecting ecosystems but prevents anyone from enjoying the area
What are the ethical, social and economic reasons for conservation?
Ethical = all organisms have the right to live and conservation ensures humans are not preventing this. Future generations are able to experience natural ecosystems
Social = enjoying outdoors provides physical and mental benefits.
Economic = medicines, food, clothes, timber are sourced from natural resources that may be lost if not conserved.
Explain sustainable timber production (coppicing).
Coppicing and pollarding are used to sustainably manage slower growing broadleaf trees.
Coppicing - felling trees close to the ground. New shoots grow from the stump and are harvested again. Trees remain small so light can always reach the ground = more diverse woodland. Woodlands are coppiced on rotation so only small areas will lack mature growth at any time.
Explain sustainable timber production (pollarding).
Trees are cut 2-3 meters above ground, leaving mature tree trunk in place. So herbivores are less likely to reach and consume the new shoots as they grow
Explain sustainable fishing.
- Leaving enough fish in the ocean (via government established fishing quotas on number and size and regulating net size)
- Protecting habitats and marine food webs that fish rely on
- Human communities that catch and process fish can maintain their livelihoods
Some areas are not allowed to be fished in, especially during mating season.
Describe the conservation of the Masai Mara region in Kenya by controlling human behaviour.
Ensuring conservation while not impacting human needs.
E.g tsetse fly is carrier of African trypanosomiasis.
To reduce its spread acacia bushes have been removed as this is the tsetse fly’s habitat.
Local tribes are not allowed to graze their livestock in the park. This enabled vegetation in the park to recover.
Ecotourism is popular (economic benefits) but must not exploit natural environments or local commuinties.
Describe the effects of human activities on animal and plant populations using a case study.
Galapagos Islands. Due to an increase in tourism, the demand for resources like water and energy has increased there. SO, the amount of waste and pollution has increased. So has overfishing, causing sea cucumbers to become threatened. Moreover, many non-native species have been introduced, which
outcompete the native species. There are several conservation projects in the
Galapagos Islands which serve to minimise those effects, such as goat culling to eliminate non-native species, turn increasing vegetation. Also, the population of giant tortoises has been depleted as they have been eaten by
humans. To increase the population size of giant tortoises, they are now bred in captivity
What are the general steps to managing ecosystems and human activity in the case studies?
- Controlling number of tourists/visitors
- Involvement of local communities
- Education of local communities
- Active management of vegetation
- Control of the introduction of species
