B22 Human influences on the ecosystem

Question 1

reasons for deforestation

Answer 1

agriculture, growing population, building, using resources from forests

Question 2

how are trees environmental buffers?

Answer 2

they intercept heavy rainfall and release it slowly into the soil. the roots hold soil in place

Question 3

what can deforestation lead to?

Answer 3

soil erosion, silting up of lakes and rivers, floods, decrease in rainfall, loss of species, increased atmospheric CO2

Question 4

causes of water pollution

Answer 4

oil, fertiliser, landfill leakage, manure/ silage from farms, radioactive waste, industrial waste, sewage, leakage from mines, urban waste (litter etc)

Question 5

Sewage and effects on water pollution

Answer 5

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

Question 6

chemical waste and effects on water polution

Answer 6

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

Question 7

Advantages of feritlisers

Answer 7

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

Question 8

disadvantages of fertilisers

Answer 8

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

Question 9

input methods for eutrophication define

Answer 9

reducing the input of nitrates and phosphates

Question 10

input methods for eutrophication

Answer 10

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

Question 11

output methods for eutrophication define

Answer 11

clean up waste bodies already suffering severe eutrophication

Question 12

output methods for eutrophication

Answer 12

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

Question 13

sources of acid rain

Answer 13

sulphur dioxide released from volcanoes

sulphur dioxide, carbon dioxide and nitrogen oxide released from the combustion of fossil fuels

Question 14

dry deposition and acid rain

Answer 14

falls near emission sources. when SO2 and NO oxidize in clouds

Question 15

wet deposition and acid rain

Answer 15

goes into water. forms sulphuric acid, nitric acid. falls great distances from source

Question 16

effects of acid rain

Answer 16

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 :))))

Question 17

solutions to acid rain

Answer 17

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

Question 18

Major threats to biodiversity

Answer 18

1) islandification
2) invasive alien species
3) pollution
4) overharvesting
5) removal of habitat

Question 19

why should we preserve biodiversity?

Answer 19

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

Question 20

ways of conserving biodiversity

Answer 20

1) banning/ prohibiting the capture/ killing of certain animals
2) captive breeding
3) zoos
4) national parks
5) seed banks

Question 21

CITES

Answer 21

international body that imposes legal framework. Individual countries manage their own people. For conservation of biodiversity

Question 22

WWF

Answer 22

an organisation that raises funds for the conservation of biodiversity