unit 6

• what is peat?

  soil over 80% composed of partially decomposed organic matter
• what are the conditions for peat to form?

  climate where precipitation exceeds evaporation

  waterlogged ground - impermeable rock

  oxygen deficiency (anaerobic conditions)

  acidic conditions
• in the Uk, peatlands...

  cover around 3 million hectares (12% of land)

  store over 3.2 billion tonnes of carbon
• what are the 3 types of peatland in UK?

  fen peatlands

  blanket peatlands

  raised bogs
• what is a blanket peatland?

  occurs on flat hill tops with impermeable rock where drainage is impeded
• what are fen peatlands?

  areas of low lying topography where groundwater meets surface
• what are raised bogs?

  occur in topographical valley bottoms where drainage of water accumulates
• how does peat form?

  waterlogged areas lacking in oxygen and water is acidic

  decomposition is restricted so dead organic matter doesn't decompose

  peat accumulates at rate of 1mm per year and carbon is preserved
• what is a key peat forming species?

  sphagnum moss without this, peats wouldnt form
• why is sphagnum moss vital?

  hold around 2ox its own weight in water acting as sponge to maintain waterlogged conditions

  as it grows it takes nutrients from environment making water acidic

  releases chemical of sphagnum which reduces decay of dead organic matter
• how much of peat in UK has been degraded due to human activities?

  80%
• what human activities are threatening peat?

  cutting peat and burning as fuel

  cutting peat and using in horticulture

  drainage of peat and use for agriculture
• what is cutting peat and burning as fuels impact on carbon?

  increases carbon in atmosphere increasing global warming

  bare land dries out further emitting carbon

  water storage reduced water log non existent & peat decays
• what is cutting peat and using in horticulture impact on carbon?

  peat harvested for use in compost

  creates net loss as much as 22.4 tonnes of co2 per hectare
• what is the drainage of peat and use for agriculture impact on carbon?

  drained water, peat is lost

  afforested areas have 2.5 tonne co2 loss per hectare
• what are management strategies of restoring peat?

  blocking drainage channels

  removing invasive shrub and tree species
• what is blocking drainage channels impact on carbon?

  water and peat aren't lost to drains

  water levels rose massively after installation
• what is effect of removing invasive shrub and tree species on peat?

  improves quality of raised peat bogs
• what is the government policy on climate change?

  increase tree planting by planting 90-120 million trees each year

  encourage low carbon farming practices controlled release fertilisers

  restore peatlands by at least 50% of upland peat
• what is a case study of peatlands?

  whixall moss Shropshire
• what is some info on whixall moss?

  3rd largest raised bog in Britain storing 3 million tonnes of carbon

  large scale drainage in 1920s for commercial peat extraction

  1990s designated national nature reserve ending drainage & extraction