3.6 Human Impact On The Environment Flashcards
Why are species at risk ?
Human activities alter ecosystem
Habitat destruction
Biodiversity crisis
What causes extinction ?
Natural process caused by poaching, disease and catastrophic change
What are endangered species?
Species of low numbers
Why are species threatened ?
Natural selection
Change/ loss of habitats
Too little genetic diversity
Isolated groups cannot interbreed
Overfishing
Agricultural exploitation
Competition
Alien species
Pollution
What is conservation ?
Management, protection, preservation of natural habitats and their ecological communities to enhance biodiversity whilst allowing suitable human activity
Why should we conserve ?
Ethical reasons
For agriculture and horticulture
Environmental changes
Medical use
How does agriculture negatively affect habitat and biodiversity ?
Hedgerow removal
Repeat growth of crops on same ground
Over grazing
What are the consequences of deforestation?
Soil erosion
Lowland flooding
Poorer soil quality
Less rainfall
Reduced biodiversity
Habitat loss
Less CO2 removed = affects atmosphere
What is over fishing ?
The rate at which fish are harvested exceeds the rate at which they reproduce
What does fishing with small nets do ?
Catches young fish that are not sexually mature so have not reproduced = Decreased genetic biodiversity
What are the methods of commercial fishing ?
Drift netting
Trawling
How does over fishing affect other wildlife ?
Affects food chain
Decreased biodiversity
Harm marine plants
What are planetary boundaries ?
Limits between which global systems must operate to prevent abrupt and irreversible environmental change
How many planetary boundaries are there ?
9
What is the climate change boundary ?
Number 1
Been crossed
Production of greenhouse gases by burning fossil fuels as well as deforestation
What is the biosphere integrity boundary ?
Number 2
Been crossed
Habitat destruction resulting in decreased biodiversity
What is the land system change boundary ?
Number 3
Avoidable
Land needed for human use leads to habitat destruction
What is the biogeochemical flows boundary ?
Number 4
Been crossed
Use of fertilisers which leads to eutrophication
What is the ozone depletion boundary ?
Number 5
Avoided
Hole in ozone layer resulting in increased UV radiation
What is the ocean acidification boundary ?
Number 6
Avoidable
High atmospheric CO2 causes ocean pH to lower = more acidic
What is the fresh water use boundary ?
Number 7
Avoidable
Fresh water needed for human consumption and agricultural use
What is the atmospheric aerosol loading boundary ?
Number 8
Not measured
Air pollution by particulates created during combustion of fuels and dust from building and quarrying
What is the chemical pollution boundary ?
Number 9
Not measured
Sulphur dioxide, SO2 and nitrous oxides cause harmful affects
What is monoculture ?
The growth of large numbers of genetically identical crop plants in a defined area
What are pesticides ?
Chemicals which kill or inhibit the growth of weeds, fungi and insects
