B22 Human influences on the ecosystem Flashcards
reasons for deforestation
agriculture, growing population, building, using resources from forests
how are trees environmental buffers?
they intercept heavy rainfall and release it slowly into the soil. the roots hold soil in place
what can deforestation lead to?
soil erosion, silting up of lakes and rivers, floods, decrease in rainfall, loss of species, increased atmospheric CO2
causes of water pollution
oil, fertiliser, landfill leakage, manure/ silage from farms, radioactive waste, industrial waste, sewage, leakage from mines, urban waste (litter etc)
Sewage and effects on water pollution
nutrients in sewage (nitrates, phosphates) can make algae in water grow quickly and cause other plants and organisms to die. basically eutrophication. can also transmit diseases in poorly sanitated places
chemical waste and effects on water polution
industrial processes produce poisonous waste products (mercury, cyanide, lead) which can be released into water and poison animals/ plants. Can affect humans who drink water/ eat organisms in it
Advantages of feritlisers
1) give nitrates to soil- help plants produce protein
2) allows for intensive farming- improves productivity- many crops grown in small area
3) ^ allows more land to be left in natural state
disadvantages of fertilisers
1) only 1/2 of fertiliser is taken up by plants. the rest runs off and leaches into water. causes eutrophication
2) can get into drinking water- cause health problems e.g blue baby syndrome
3) it requires energy from fossil fuels to manufacture fertilisers- increases pollution
input methods for eutrophication define
reducing the input of nitrates and phosphates
input methods for eutrophication
1) treat sewage- very expensive- removes phosphates
2) banning use of phosphates in cleaning agents
3) direct water waste away from lakes and to seas
4) alternative methods of enhancing crop growth
output methods for eutrophication define
clean up waste bodies already suffering severe eutrophication
output methods for eutrophication
1) precipitating phosphates- clumping them together and removing them
2) aerate lakes and reservoirs- prevent oxygen depletion, encourage exposure to sunlight
3) remove plant material
4) reintroduce fish and plant species
sources of acid rain
sulphur dioxide released from volcanoes
sulphur dioxide, carbon dioxide and nitrogen oxide released from the combustion of fossil fuels
dry deposition and acid rain
falls near emission sources. when SO2 and NO oxidize in clouds
wet deposition and acid rain
goes into water. forms sulphuric acid, nitric acid. falls great distances from source
effects of acid rain
1) soil fertility decrease
2) leaching- removes calcium and magnesium from soil
3) top of trees die due to contact w/ acid
4) interfere with fish gil function
5) damages plant tissue
6) decreases species diversity
7) damage respiratory pathways
etc etc kms :))))
solutions to acid rain
1) catalytic converters- encourage pollutants to react with another
2) local application of alkali (tipping limestone into water)
3) adding supplementary nutrients to forests
4) monitoring chemical levels
Major threats to biodiversity
1) islandification
2) invasive alien species
3) pollution
4) overharvesting
5) removal of habitat
why should we preserve biodiversity?
1) food sources
2) many plants used in medication
3) biological insurance- monocultues are susceptible to pest attack
4) conserve genetic material
5) in industrial products
6) ethical reasons
7) aesthetics
8) help regulate ecosystem
ways of conserving biodiversity
1) banning/ prohibiting the capture/ killing of certain animals
2) captive breeding
3) zoos
4) national parks
5) seed banks
CITES
international body that imposes legal framework. Individual countries manage their own people. For conservation of biodiversity
WWF
an organisation that raises funds for the conservation of biodiversity
