Unit 6 Notes Flashcards
(36 cards)
What is Peat?
A soil in which over 80% is composed of partially decomposed matter, which has accumulated under certain conditions.
What are the correct conditions for peat to form?
Climate where precipitation exceeds evaporation, waterlogged ground, drainage depressions in landscape. Oxygen deficiency, acidic conditions.
What is the distribution of global peatlands?
Mostly in the Northern Hemisphere. Canada, Northern Europe, Russia. More spatious in areas such as SA, Africa, Oceania.
What are the different types of peatland in the UK?
Fern peatlands, blanket peatlands, raised bogs.
What are Fern Peatlands?
In areas of low lying topography where groundwater meets the surface.
What are Blanket Peatlands?
Occurs on flat hill tops, with impermeable rocks, where drainage is impeded.
What are raised bogs?
Occur in topographical depressions/valley bottoms, where drainage of water from surrounding landscapes accumulates.
What are the statistics about peatlands in the UK?
Covers around 3 million hectares, 12% of land area. Stores over 3.2 Billion tonnes of carbon.
What are the examples of peatlands in the UK?
Flow country, Sutherland. Whixall Moss, Shropshire. East Anglian fens.
What is the relationship between peat and the Carbon cycle?
Occupy 3% of the global land surface. 12% of the UK’s land surface. A major carbon sink, storing over 500 gigatons of Carbon.
How much Carbon do UK peatlands store?
Over 3.2 Billion tonnes.
How does Peat form?
Forms in waterlogged areas, lacks oxygen, where water is acidic. Decomposition is restricted, so dead organic matter doesn’t decompose. Over thousands of years, peat accumulates at a rate of 1mm per year.
What has happened to peat since the end of the Devensian period?
Ireland was covered in Snow and Ice 12,000 years ago. This ice melted 10,000 years ago, as climate became warmer. This formed lakes in low lying areas.
What has happened to peat formation since the Holocene period?
Plants grew around the edges of lakes, when they died, accumulated at the bottom of the lake. During dry periods in Ireland, the climate 4,500 years ago, trees colonised bogs, and died when the climate became wetter. After hundreds of years, the area plants had filled the entire lake.
What has happened to peat in the present day?
New types of plants such as Sphagnum moss colonised the surface of the fen, as they died, accumulated, and transformed the fen. Over the years, the centre of the bog became elevated, like a dome, and was known as ‘raised bogs.’
Why is Sphagnum moss vital?
It can hold 20x its’ own weight in water, acting as a sponge, helping maintain waterlogged conditions. It takes up nutrients, releases a chemical which has antibacterial priorities.
What % of UK peatlands have been degraded?
80%.
Why have UK peatlands been degraded?
Peat cutting and extraction for fuel and horticultural use, drainage and conversion to agricultural land.
What are the examples of land use and tonnes of C02 they hold?
Cultivated Grass - 22.4 Ton NL. Improved Grassland - 8.7 Ton NL. Afforested Land - 2.5 Ton NL. Bare Peat - 0.1 Ton NL. Undamaged Land - 4.1 Ton NS.
How does cutting and burning peat impact the environment?
Releases large amounts of C02, adding more C02 into the carbon cycle.
How does using peat for Bio-culture impact the environment?
Need to dry peat to use it - destroys ecosystems. When it’s gone, you can’t get it back.
How does the drainage of peat impact carbon?
Only 4% of bogs planted with trees - small scale damage.
What are the different management strategies to manage peatland?
Blocking drainage channels, removing invasive shrub and tree species, Re-seeding damage areas with sphagnum moss.
How does blocking drainage channels impact peatlands?
Done by creating peat dams using machinery if too wet, plastic dams installed manually.
