Carbon Cycle Pack E

Question 1

What is peat?

Answer 1

A thick layer of dark brown/black wet soil

Question 2

How much global land surface do peatlands cover?

Answer 2

3%

Question 3

How much carbon is stored in global peatlands?

Answer 3

• 550 billion tonnes
• As much as is contained in all terrestrial biomass

Question 4

How deep can peatlands be?

Answer 4

• 40cm to 4m in the UK
• Up to 10m globally

Question 5

Where are peatlands found?

Answer 5

• N Canada
• N and E Europe
• Along Amazon River
• S Chile
• UK
• Finland
• N Russia/Siberia
• DRC
• SE Asia

Question 6

What vegetation is found in peatlands?

Answer 6

• Sphagnum moss
• Rushes
• Sedges
• Bracken

Question 7

How does peat form?

Answer 7

• Plant remains are slowly compressed as more matreial is added each year
• Layers of dead matter accumulate
• Decomposition is prevented by a waterlogged environment, creating anaerobic conditions
• This limits microbial decomposition of organic matter
• Despite carbon loss by the water cycle, there is a net accumulation of carbon in undisturbed areas
• Rate at which atmospheric carbon is fixed by photosynthesis in new peat/plants greatly exceeds the loss of carbon through decomposition of leaf litter

Question 8

Why is decomposition even more limited in upland peatlands?

Answer 8

• Temperatures are cooler
• Vegetation is more acidic, deterring soil organisms

Question 9

How do peatlands exist in the tropics?

Answer 9

• Humid conditions
• Composed of the remains of rainforest trees
• Peatlands of Indonesia have low relief, impermeable rock and high rainfall
• They store 60 billion tonnes of carbon and can reach 15m deep

Question 10

What percentage of peatlands in the UK are not degraded?

Answer 10

20%

Question 11

Why are peatlands being degraded?

Answer 11

• Cutting or extracting peat to burn as a fuel for industrial use
• Extracted for the horticultural industry and sold as a nutrient rich soil and compost (until recently)
• Burnt as part of the whiskey making process in Scotland

Question 12

How is peat used as a fuel?

Answer 12

• Once dried, it can be burnt
• It is a non-renewable resource due to the long time it takes to form
• Being harvested for fuel on an industrial scale for power stations in Ireland and Scotland

Question 13

How much carbon is released from the drainage, burning, cultivation and extraction of peatlands?

Answer 13

• 2 billion tonnes of CO2 every year
• 5-10% of global carbon emissions from all human activities
• Emissions are especially high from Indonesia

Question 14

Why are peatlands being degraded in the UK?

Answer 14

• Drainage for agriculture
• Air pollution
• Moorland burning
• Invasive species
• Drained for forest

Question 15

Why are peatlands being degraded by drainage for agriculture?

Answer 15

• 1/4 of English peatland is under cultivation
• Drained for agricultural land
• Peat shrank, decomposed and became eroded by wind

Question 16

Why are peatlands being degraded by air pollution?

Answer 16

• Yorkshire peatlands subject to pollution from Manchester and Sheffield
• Led to widespread reduction in peat-forming plants, so they are more vulnerable to erosion

Question 17

Why are peatlands being degraded by moorland burning?

Answer 17

• Done to manage game
• Encourages the growth of young heather for grouse to feed on
• Damages sphagnum moss
• Too much burning exposes below as vegetation is removed, leading to erosion during heavy rainfall

Question 18

Why are peatlands being degraded by invasive species?

Answer 18

• 1/3 of English peatlands support invasive vegetation species

Question 19

Why are peatlands being degraded by drainage for forestry?

Answer 19

• Forestry Commission drained peatlands for commercial forests
• Will emit CO2 and lose soil carbon via leaching and erosion
• May be offset by growing trees

Question 20

What does the restoration of peatlands usually include?

Answer 20

• Re-establishment of plant cover dominated by peat and species
• Re-wetting of drained peatlands by raising and stabilising local water table

Question 21

How are peatlands restored?

Answer 21

• Blocking drainage channels to increase infiltration and raise water table
• Creates anaerobic and waterlogged conditions
• Raised banks or berms to prevent drainage
• Wetland plants re-established
• Adopt the peatland code, encourage investment into restoration in the UK

Question 22

How long does peat restoration take?

Answer 22

20 years

Question 23

What is the peat degradation in Indonesia?

Answer 23

• Have peat swamp forests formed by dead bits of trees that have fallen to the ground and accumulated in waterlogged conditions
• Caused by logging for timber
• Waterlogged soil is drained by creating trenches to carry logs
• As sunlight enters, peat dries out and O2 enters so decomposition starts
• Large scale damage can cause peat fires as there is no tree cover
• Ground heats up and driers out, in a positive feedback cycle

Question 24

What is the peat restoration scheme in Ireland?

Answer 24

• A good fuel material because it is easily combustible and stores lots of C
• 80% of peatland lost for domestic use
• Bord Na Mona is restoring peat lands and building wind turbines
• Restoration involves blocking previous drainage channels to create pools of water and adding sphagnum moss
• Takes 50 to 100 years
• Conflict as locals have lost their fuel source, peat cutter have lost their jobs and tradition has been lost

Question 25

What is the peat restoration scheme in Canada?

Answer 25

- In St Henry peatland, Quebec - Use moss layer transfer technique - Area is flattened and berms are built to keep water in - Donor site provides plants from the top layer - Taken to restoration site and covered with straw for protection from sun - Area allowed to flood