topic 7

Question 1

carbon cycle main processes

Answer 1

photosynthesis
respiration
food webs
fossilisation-incomplete decomp of dom-anaerobic conditions
combustion

Question 2

changes of carbon cycle human

Answer 2

photosynthesis-deforestation+afforestation
aerobic respiration-less aerobic respiration in soil-ploughing
anaerobic-methane gas released instead-rice Padi fields + Peat Bogs
combustion of fossil fuels

Question 3

sustainable management of the carbon cycle

Answer 3

conservation of carbon stores-amazon
carbon sequestration-afforestation
CCS-
pre combustion tech-small scale-
oxy-fuel-only produces water vapour and c02-easier to extract c02 isnt mixed with other gases
post combustion-
injected into depleted oil reserves or secondary oil recovery-maintains pressure

Question 4

nitrogen cycle processes

Answer 4

fixation-nitrogen-ammonia
nitrification-oxidation of amonia ions to nitrites-nitartes
denitrrification-nitrate-nitrogen-anaerobic
leaching-nitrates high solubility
root absorption
ammonification-break down of DOM into ammonia

Question 5

human impacts of nitrogen cycle

Answer 5

haber-nitrogen+hydrogen=ammonia
needs iron catalyst+energy -expensive
agriculture-fertilisers-eutrophification
leguminous crops-increase nitrogen compounds

Question 6

sustainable management of the nitrogen cycle

Answer 6

control of Nox-catalytic converter
cultivation of legume crops
crop rotation
low tillage techniques-less soil disturbance

Question 7

phosphorus cycle processes

Answer 7

absorption by roots-symbiotic relationship with myccorhizal fungi
decomposition
sedimentation-may get lost with
mountain building and weathering-slow weathering +uplift-slow

Question 8

human impacts on phosphirus cyclse

Answer 8

minig of phos[hate rocks- guano
fertiliser use-eutrophifciation

Question 9

sustainable management-phosphoorus cycle

Answer 9

use of biological waste
crop breedding programmes-increase efficeincy iof phopshorius absorption