carbon cycle 2.1.8 - changing carbon stores in peatlands Flashcards
what is peat
Peat is thick organic soil formed from the accumulation of partially decomposed vegetation (mosses, bracken and sedges) , in waterlogged conditions.
where are peatlands found
Peat is found in areas of high soil moisture levels but low average temperatures (as that increases decomposition rates)
as well as found in locations that have higher precipitation rates than evapotranspiration rates
how is decomposition prevented
prevented due to waterlogging, which creates oxygen-deficient anaerobic conditions - limiting microbial decomposition of organic matter
name the 3 types of peatlands
- Fen peatlands
- Blanket bog
- Raised bogs
why is peat an important carbon store
There are 5 main facts that must be remembered
How much of earth’s surface is covereby peat, what country size is it equiverlent to
Why is timescale important to mention in relation to peat establishment and it being destroyed
What happens if left undisturbed
Peatlands are important because they are a Carbon sink
1. Peat sequesters more carbon than all vegetation in the world combined
2. Peat sequesters 2 x more carbon than is stored in all forests
3. Peat in the UK alone stores 3 Gtc
- Degradation of 5% of uk peatland would be the equivalent to the annual uk green house gas emissions
- Degradration of peatlands accouns for 7% of global co2 emissions
- Peatlands cover 3% of earths surface
(larger than India)
-If left undisturbed, peat can be a net accumulation of carbon overtime
-it is a carbon sink
-takes 100,000 years to established peatland, but can be destroyed instantly
explain where Fen Peat lands are found
Fen peatlands are formed where the ground water meets the surface, which is normally near springs and edges of open water
explain where Blanket bogs are found
Blanket bogs are found on flat hill tops where rainfall is high
explain where raised bogs are found
Raised bogs are found in valley bottoms, where soil is saturated due to the through-flow and overland flow from the slopes above.
what are the 4 ways peatlands are being degraded and destroyed by
- burning
- pollution
- drainage
- forestry
where and why was peatlands being burned
large areas of peat in the UK are being affected by moorland burning, in order to manage grouse hunting
where and why are peatlands being drained
1/4 of the uk’s peat is under cultivation
In East Anglia, fens are being drained for farming to produce good agricultural land, but it degraded the peat
where and why are the peatlands being affected by pollution
the peat in Yorkshire has been affected due to decades of pollution from Manchester and Sheffield, harming peat-forming plant from growing
where and why are the peatlands being affected by Forestry
peatlands are being drained by the forest commission, the soil will begin to emit carbon due to leaching and erosion
an arguement against this, is that the trees growing will capture the carbon lost
name the 3 direct threats to peatland degradation
and the one indirect threat
- agriculture- farmers want the land because they wouldn’t have to pump water to their crops
- burning- on shooting estates they burn it until it is just young heather growth
- illegal offroading - increases drainage (making gullies)
- climate change - increase of evapotranspiration over precipitiation (needs to be precipitation more so it can remain waterlogged)
what management can be done to restore this peat degradation (restoration of carbon storage through management of peatlands)
- Bare peat Restoration (jute, seeds, brash)
2.Gully management and hag re-profiling - Grip blocking(increase water tention- pools of water separated but higher soils)
- Sphagnum proporgation ( adding it to degrading peat, to encourage growth)
- Restoration of peatlands- reestablishing plant cover and re-wetting drained peat by stabilizing the water table)
- Management of peatlands ( encouraging tourists to stick to a pre-made path, to prevent trampling)
