C1: Human impact on the environment Flashcards
Define extinction
The total loss of a species
Define endangered
A species at serious risk of extinction
Name five reasons for extinction
Natural selection
Habitat destruction (deforestation )
Pollution (Higher CO2 in ocean means mollusc shells become softer)
Poaching
Competition from domestic animals
Define conservation
Is the planned management of ecosystems to enhance and protect gene pools
Name six conservation methods
Nature reserves and SSSI’s (sites of special scientific interest)are protected by law
Banned trades of endangered species and products
Captive breeding programmes in zoos and botanic gardens enhance species numbers
Sperm and seed banks preserve gene pools for the future
Reintroduction programmes
Fishing quotas
why conserve gene pools ?
three reasons
Plants may provide medicines for the future
it is the ethical thing to do
reduced gene pools make species more vulnerable to extinction
Define agricultural exploitation
Describes the need to increase the efficiency and intensity of food production to meet the increasing demands of a rapidly increasing human population.
What is the conflict of agricultural exploitation
there is a conflict between the need for the conservation of species and the demand for increased food production. as methods of agricultural exploitation decrease biodiversity
Why does agricultural exploitation decrease biodiversity
4 points
Removal of hedgerows - destroys habitats
Monocultures - reduce available niches
Use of insecticides, herbicides and fertilisers cause death of beneficial insects, niches and habitats and causes eutrophication
Ecosystem destruction to provide additional agricultural land
define deforestation
The removal of trees to use as timber or fuel or to repurpose the land use for agriculture or building
What are the consequences of deforestation
5 points
Soil erosion - It is not protected from rain by the canopy, as roots decompose they no longer hold the soil together so it is eroded by wind and rain.
Flooding - evaporation from soil removes less water than transpiration, waterlogging encourages denitrification and soil loses nitrates.
Habitat loss reduces biodiversity
Less photosynthesis means that less CO2 is removed from the atmosphere. CO2 is a ‘greenhouse gas’, increased CO2 leads to global warming and climate change.
Burning of cut down trees releases CO2 into the athmosphere, CO2 is a ‘greenhouse gas’, increased CO2 leads to global warming and climate change.
What are some solutions to deforestation
3 points
Selective felling.
Replanting the correct mix of species, the correct distance apart, and allowing them to regenerate.
Protecting areas.
Define overfishing
Is where fish are caught at a higher rate than they can reproduce and grow ( fished at a biological unsustainable level) to the point where increased fishing efforts lead to declining catches.
What are the consequences of overfishing on fish stocks
3 points
Fish populations may be reduced in size to the extent that they lose genetic diversity.
Size of fish caught is reduced as they don’t have time to grow.
Fish population has fewer individuals and cannot replace harvested fish.
Name five solutions to overfishing
Quotas - max amount of fish that can be harvested
Restricted fishing seasons - to allow fish to reproduce
Exclusion zones - prevents fish in selected areas
Legislation - limits size of fishing fleets and mesh size to allow small fish to escape and grow to breeding size
Fish farming
Define fish farming
Is where fish are intensively reared in ponds/tanks or nets; sea-fish are usually reared in large netted areas of the sea. This is one solution to over-fishing
Two Positives of fish farming
Less fish need to be harvested from the Wild, allowing fish stocks to replenish
Fish have been selected for high growth rates and therefore have large sizes and therefore there is an increased yield
Five negatives of fish farming
Toxic waste can cause eutrophication
Parasites and diseases spread quickly through the overcrowded fish
Antibiotic use may lead to antibiotic resistance and using pesticides to control parasites will harm marine invertebrates
If farmed fish escape they could outcompete wild fish or interbreed with them, passing on the alleles for fast growth, which could increase the rate of extinction of wild fish- triploid farmed fish can prevent this
The feed is often made from harvested wild fish
How might conservation methods be monitored
Biological monitoring may involve field techniques like random sampling and transects.
Why should conservation methods be monitored
3 points
Monitoring enables prediction of possible effects of human activities to inform planning of conservation methods.
To determine the effect of these methods and if Alternative methods need to be considered and implemented to reduce harmful effects.
To inform political decisions as they should be based on the latest scientific data
Define planetary boundries
A safe operating level for humanity/ a threshold value for a global process that is affected by human activity. Above this value, the global process will not be stable and exceeding boundary leads to irreversible damage globally.
Name all 9 planetary boundries
Name the two core boundries
Biodiversity
Climate change
Nitrogen boundary
Land use
Fresh water
Chemical pollution
Aerosol
Ocean acidification
Ozone
Bold = Core boundary
Describe the Biodiversity / biosphere integrity boundary
has it been crossed?
It has been crossed:
Extinction in relation to natural selection; the change of habitats such as marine, tundra; coral reefs and coastal plains and its effect on indigenous species; Biodiversity monitoring; the use of gene banks; public awareness
Describe the climate change boundary
has it been crossed?
The climate change boundary has been crossed:
Greenhouse gases and their sources; the production and use of biofuels; the effect on human populations; the effect on plant and animal populations.
Describe the nitrogen boundary
has it been crossed?
The nitrogen boundary has been crossed:
The nitrogen cycle and the effects of eutrophication
Describe the land use boundary
has it been crossed?
The land use boundary has been crossed:
The conflict over land use and food production; changes to farming practice; political considerations.
Describe the fresh water boundary
has it been crossed?
The fresh water boundary has not been crossed and it is avoidable:
The need for fresh water; sources of fresh water; desalination
Describe the chemical pollution boundary
has it been crossed?
The chemical pollution boundary is unquantified:
air pollution including the effects of SO2 and N oxides.
Describe the aerosol boundary
has it been crossed?
The aerosol boundary is unquantified:
air pollution by particulates
Describe the ocean acidification boundary
has it been crossed?
The ocean acidification boundary as not been crossed and is avoidable: the effect of fossil fuel burning on oceans; fish farming.
Describe the ozone boundary
has it been crossed?
The ozone boundary has been avoided:
CFCs and the chemistry of ozone destruction; the effect of the Montreal protocols.
