B7: BIODIVERSITY + HUMAN IMPACT Flashcards
What is biodiversity?
the variety of different species of organisms on earth/within an ecosystem
How does having a high biodiversity impact the stability of an ecosystem? why?
-having a high biodiversity increases the stability of an ecosystem
-because there is more than one species to rely on for food/shelter
What are some examples of human activities that reduce biodiversity?
-deforestation (less CO2 taken in, more CO2 released, destruction of habitats)
-pollution/waste (toxic, kills organisms)
-burning fossil fuels (increase in CO2 which increases global warming: affects distribution, loss of habitats)
-land use (destruction of habitats)
-hunting/poaching/over-fishing (kills organisms)
-mining/fracking/quarrying (destruction of habitats)
-agriculture (use of herbicides and pesticides)
What are the 3 types of pollution?
-water pollution
-land pollution
-air pollution
What are the causes of water pollution?
-sewage
-toxic chemicals from industry
-oil spills into water
-chemicals used on land for crops (fertilisers/pesticides/herbicides) washed into water
What are the causes of land pollution?
-toxic chemicals
-landfill sites
-nuclear waste underground
What are the causes of air pollution?
-smoke and acidic gases (eg: sulfur dioxide/CO2) from burning fossil fuels
What is acid rain caused by?
-sulfur dioxide and nitrogen oxides being dissolved in water before precipitation
What are the impact of acid rain?
-kills plant species by damaging leaves
-kills aquatic species by increasing acidity of aquatic ecosystems
-decreases soil and mineral content
Why do we use more resources and produce more waste?
-rapid growth in human population
-increased standard of living
Why do humans use land?
-landfill sites
-agriculture/farming
-building
-mining/quarrying
What is peat?
a brown soil-like material formed from partially rotted plants in acidic and waterlogged areas
What is a peat bog?
poorly drained areas made up of partially decomposed organic matter due to waterlogging
What do peat bogs store?
carbon
Why are peat bogs drained?
-so area can be used as farmland
-so peat can be used as fuel
-so peat can be used as compost
What are the negative impacts of destroying peat bogs?
-releases CO2 due to decay
-burning of peat releases CO2
-destruction of habitat decreases biodiversity
Why has large scale deforestation occurred in tropical areas?
-to clear land for cattle and rice fields
-to grow crops for biofuels/palm oil
Why has large scale deforestation occurred in temperate forests?
-to obtain wood for paper/building
-to clear land for farming
What are the negative impacts of deforestation?
-less trees to take in CO2 for photosynthesis leads to an increase in CO2 which leads to an increase in global warming
-destruction of habitats decreases biodiversity
-burning wood increases CO2 which increases CO2 which leads to an increase in global warming
-decomposition of wood leads to an increase in CO2 which leads to an increase in global warming
-soil erosion
What are the greenhouse gases and where do they come from?
-CO2 (from deforestation and burning fossil fuels)
-CH4 (from landfill and cattle farming)
-water vapour
What causes the greenhouse effect?
-sun emits short wavelength radiation (UV)
-earth heats up and emits long wavelength radiation (IR)
-greenhouse gases absorb long wavelength radiation and emit it in all directions
-some long wavelength radiation is reabsorbed by the earth and heats it up
What are the consequences of global warming?
-rising sea levels which leads to loss of habitats and floods
-extreme weather events
-higher levels of smog
-changes in distribution of animals
-changes to migration patterns
-less biodiversity (if species do not adapt to changing environment they will not survive and may lead to extinction)
-impact on agriculture and food security
How are we trying to reduce our impact on biodiversity?
-deforestation - reduction of deforestation by government legislation and programmes to protect/regenerate habitats
-water pollution - sewage management/treatment, avoiding fertiliser surface run off (amount and timing of using fertiliser)
-air pollution - reduction of carbon dioxide emissions by government legislation, Reduction of acidic gases (sulphur dioxide, nitrous oxides)
-land pollution - reduce, reuse, recycle rather than landfill
-land use (building/quarrying/farming/waste) - regulations and protection of rare habitats
-destruction of peat bogs/habitats - protection and regeneration of rare habitats, breeding programmes
global warming - government legislation and regulations , reduction of CO2 emissions
What do farmers do that decrease biodiversity?
-add fertiliser to crops (causes eutrophication when it runs off into water)
-some farmers only grow one crop
-use herbicides and pesticides
