Environment Flashcards
Give examples for the importance of biodiversity and conservation
Food and potential foods
Medicines
Stability of ecosystems
Materials
Well-being and moral duty
What are some threats to biodiversity?
Habitat destruction (drainage channels, hedgerow removal, deforestation)
Invasive species
Pollution (fertilisers, pesticides, CO2, oil, PCB’s)
Population increase
Overexploitation (hunting, overfishing, ivory trade)
What does endangered mean?
A species at risk of becoming extinct throughout all or a significant portion of its range.
What does extinct mean?
The death of the last individual of a species capable of reproduction.
What is natural selection?
Variation in a characteristic due to mutation. Those with the advantageous alleles are more likely to survive and pass on their alleles to offspring.
What is conservation?
The protection, preservation, management and restoration of natural habitats and their ecological communities. The aim is to maintain species and genetic biodiversity while allowing human activity to continue.
Give examples of methods to achieve conservation
Protecting habitats (SSSI’s and nature reserves)
International co-operation restricting trade (ivory trade and whaling)
Seed and sperm banks (Kew Gardens)
Captive breeding
International organisations (WWF)
Legislation and education
What is agricultural exploitation?
The way food production has had to increase in efficiency to maximise crop yields to feed a growing population.
Give examples of harmful farming practices
Monocultures- the growth of large number of genetically identical crops in a defined area
Pesticides- include chemicals which kill or inhibit the growth of weeds, fungi and insects
Chemical fertilisers- include the elements N, P and K to increase plant growth
What can harmful farming practices lead to?
A decline in biodiversity and overgrazed land, which can cause soil compaction, reduced air spaces and inhibit nitrogen fixings and nitrifying bacteria. This leads to a loss of soil fertility.
Give examples of better farm practices that have been introduced
Organic farming- reduces the need for chemical fertilisers and pesticides and allows for crop rotation on smaller fields
Set-aside schemes- farmers set aside land for conservation and wildlife and get compensation
Legislation- reimplementing hedgerows as habitats and food sources
What is deforestation?
The removal of a forest or stand of trees without the intent of replacing them and where the land is thereafter converted to a non-forest use.
Give examples of the damaging effects of deforestation
Soil erosion
Low land flooding
Desertification
Habitat loss
Decrease in biodiversity
Climate change
Give examples of effective woodland management
Coppicing- tree trunks cut and their base, leaving a stump from which shoots can be harvested
Selective cutting- Thinning and Pollarding
Long rotation time
What is overfishing?
This occurs when the rate of fish harvested exceeds the rate at which they reproduce.
Give some examples of methods to reduce the impact of fishing
Regulating mesh size
Quotas and landing size regulations
Exclusion zones
Marine stewardship council certification
Using lines, not nets
What is fish farming?
Large scale intensive farming where fish are bred and mature in enclosed ponds. Food, predation, disease and parasites are controlled and warm water is used to accelerate growth.
Give examples of the negative aspects of fish farming
Rapid spread of disease and parasites due to high density. Controlled by antibiotics which can enter the food chain.
Pesticides and nitrogenous waste bioaccumulate.
Escaped fish may carry disease and parasites to wild populations and outcompete them.
Farmed fish contain high levels of toxic chemicals such as methyl mercury, dioxins, pesticides and PCB’s.
What can we monitor to determine the quality of an environment?
Air quality
Soil quality
Water quality (chemical, biological ad microbiological aspects)
What is an environmental impacts assessment?
A document which uses data to predict the environmental effects of a proposed project.
Give examples of what an environmental impact assessment should include
Description of the site and proposed project
Description of abiotic and biotic factors
Mitigation
What is mitigation?
Ways of limiting environmental damage and maintaining biodiversity.
What are planetary boundaries?
Limits between which global systems must operate to prevent abrupt and irreversible environmental change.
Describe the status, threats and preventions of the aerosol boundary
Status: Not quantified
Threats: Air pollution by particulates causes respiratory problems and reduces the rate of photosynthesis.
Prevention: Sulphates in aerosols reflect sunlight, providing a cooling effect but aerosols are variable.
Describe the status, threats and preventions of the chemical pollution boundary
Status: Not quantified
Threats: Lots of chemicals used in products, microplastics, air pollution from sulphur dioxide and nitrous oxide.
Prevention: Toxic chemicals such as DDT and PCB’s are already banned.
Describe the status, threats and preventions of the climate change boundary
Status: Crossed
Threats: Disruption of the carbon cycle due to burning fossil fuels, deforestation and increased decomposition. The release of CO2 on a massive scale causes climate change due to enhanced global warming.
Prevention: Growing more biofuel crops removes CO2 from the atmosphere.
What is the greenhouse gas effect?
Gases such as CO2 in the planets atmosphere insulate the planet from losing heat to space, raising its surface temperature.
Describe the status, threats and preventions of the biodiversity boundary
Status: Crossed
Threats: Human activity introduces new selection pressures which decrease biodiversity in reaction to natural selection and increases the rate of extinction.
Prevention: Monitoring biodiversity indicates which species should be prioritised in taking material for seed banks.
Describe the status, threats and preventions of the ocean acidification boundary
Status: Avoidable
Threats: CO2 from the air dissolves in bodies of water to form H+ and HCO3-, lowering pH. This damages mollusc and coral shells and damages fish gill structure.
Prevention: Reduction in fossil fuel combustion may prevent oceans undergoing catastrophic change.
Describe the status, threats and preventions of the nitrogen boundary
Status: Crossed
Threats: Agricultural fertilisers used so intensively the nitrogen cycle is no longer self-sustaining. Eutrophication also further damages ecosystems
Prevention: An aim is to transfer nitrogen fixing genes to crop plants.
Describe the status, threats and preventions of the freshwater boundary
Status: Avoidable
Threats: Freshwater availability decreased due to agriculture, pollution and climate change.
Prevention: Water conservation and efficiency, drip irrigation for crops and desalination.
Describe the status, threats and preventions of the land use boundary
Status: Crossed
Threats: Deforestation due to expansion for agriculture and urban development, misuse of land that results in too little food being produced.
Prevention: Global reduction in meat consumption and genetically modified plants.
Describe the status, threats and preventions of the ozone depletion boundary
Status: Avoided
Threats: CFC’s used in spray cans, solvents and refrigerants damaged the ozone layer which protects against UV, so skin cancers and cataracts increased in number.
Prevention: The Montreal protocol banned the manufacture of CFC’s and placed obligations on nation states to reduce their CFC use.
What is the ozone layer?
A layer in the stratosphere, 10-50km up where ozone (O3) and oxygen are in equilibrium.
What is the name of the protocol that banned CFC use?
The Montreal protocol
