Unit 3.1 - W&C - Peatlands Flashcards
What are peatlands?
Landscapes where layers of peat have accumulated. Globally, peatlands cover many hundreds of square km’s, with thicknesses of 10 metres or more.
What is peat?
Peat is a thick layer of black or dark brown sticky and wet soil material containing high levels of partially decomposed vegetation (mosses, rushes, sedges and bracken).
Describe the formation of peat?
The carbon-rich plant remains are slowly compressed as more material is added each year; in the UK, peat can be 2-4 metres deep.
Decomposition is prevented by waterlogging, which creates oxygen-deficient anaerobic conditions. This limits microbial decomposition of organic matter, especially in cooler upland sites.
There is a net accumulation of carbon over time in undisturbed peatland: the rate at which atmospheric carbon is fixed in new peatland plants by photosynthesis greatly exceeds the loss of carbon through decomposition.
How much carbon do peatlands store?
Peatlands store 550 billion tonnes of carbon.
Name and describe the different types of peatland in the UK.
Fen peatlands form where groundwater meets the surface – usually at springs, or the edge of open water.
Blanket peatlands occur on flat hill tops where relief rainfall is high. Raised bogs occur in valley bottoms where soils are saturated, due to the frequent arrival of throughflow and overland flow from the slopes above (as part of the water cycle).
How have peatlands been affected by human activity.
Only 20 per cent of UK peatlands are not degraded and remain in their natural state. Rates of carbon sequestration in degraded peatlands are reduced; some may become sources of carbon emissions instead.
Peat has been dried and burned traditionally in many rural areas as a fuel source for centuries or millennia.
Peat is extracted for use in garden centres, and food and drink industries, including smoked food and whisky.
How can proper management affect peatlands and their role in carbon storage?
Peatland protection and restoration helps the UK meet reduction targets for long-term greenhouse gas emissions by offsetting emissions produced by economic activity.
This is called an ecosystem services management approach. However, peat formation takes thousands of years. Even when using the best management techniques, it will take decades or centuries to restore and recreate very badly damaged peatlands.
