Unit 6: Carbon Cycle Flashcards
(26 cards)
What is Peat?
Peat is a soil in which over 80% is composed of partially decomposed organic matter.
It accumulates under the following conditions:
- Climate where precipitation exceeds evaporation. - link to water cycle!!
- waterlogged ground (linked to impermeable rock, and /or high water-table, and or drainage depressions in landscape
- oxygen deficiency (anaerobic conditions)
- acidic conditions
What are the 3 types of peat in the UK, and what are they?
• Fen peatlands:
- in areas of low lying topography where groundwater meets the surface
• Blanket peatlands:
- occur on flat hill tops, with impermeable rocks (many igneous and metamorphic rocks), where drainage is impeded
• Raised bogs:
- occur in topographical depressions/valley bottoms where drainage of water from the surrounding landscape accumulates
What % of the land area in the UK are covered by peat?
12
How does peat form?
Peat forms in waterlogged areas, lacking in oxygen and where the water is acidic.
In these conditions’ decomposition is restricted so that dead organic matter (DOM) doesn’t decompose.
Over thousands of years peat accumulates at the rate of about 1mm per year.
Consequently, carbon is preserved and makes up 50% of the DOM.
What are the 3 types of peat in the UK, and what are they?
• Fen peatlands:
- in areas of low lying topography where groundwater meets the surface
• Blanket peatlands:
- occur on flat hill tops, with impermeable rocks (many igneous and metamorphic rocks), where drainage is impeded
• Raised bogs:
- occur in topographical depressions/valley bottoms where drainage of water from the surrounding landscape accumulates
Why is Sphagnum Moss vital to forming peat?
- it can hold around 20 times its own weight in water, effectively acting as a sponge and helps maintain waterlogged conditions
- as it grows it takes up nutrients such as potassium and magnesium from the environment and release hydrogen ions; hence making the water acidic typically below
pH 4.5 (acidity preserves organic
matter - think pickled onions) - releases a chemical called sphagnan which has antibacterial properties and reduces
decay of organic matter
What is the impact of cutting peat and burning it as fuel?
Releases stored carbon into the atmosphere, contributing to greenhouse gas emissions.
How does draining peat for agriculture or forestry affect the carbon cycle?
Draining peat reduces its ability to store carbon and leads to increased CO₂ emissions.
What is the role of blocking drainage channels in peatland management?
Helps retain water, restores peatland ecosystems, and prevents carbon loss.
Why is re-seeding damaged areas with sphagnum moss beneficial?
Sphagnum moss helps rebuild peat layers, improving carbon sequestration.
What government policy was outlined by the Committee on Climate Change in January 2020?
Proposed changes in land use and farming to meet the UK’s Net Zero emissions target by 2050.
Why is Whixall Moss important for peatland conservation?
It is a rare lowland raised bog that stores vast amounts of carbon and supports biodiversity.
What human activities have affected Whixall Moss?
Industrial peat extraction, drainage for agriculture, and past land use have led to habitat degradation and carbon loss.
What restoration efforts have been carried out at Whixall Moss?
Blocking drainage channels, rewetting the bog, and reintroducing sphagnum moss to aid peat formation.
How does restoring Whixall Moss help with climate change?
Healthy peatlands act as carbon sinks, reducing atmospheric CO₂ levels.
What role do conservation organizations play in protecting Whixall Moss?
Groups like Natural England work to preserve and restore the site through management strategies.
What wildlife benefits from peatland restoration at Whixall Moss?
Species like curlews, dragonflies, and rare plants thrive in the rewet peatland habitat.
What are some of the restoration methods used at Whixall Moss?
• Blocking drainage channels
- Retains water to restore bog conditions.
• Rewetting the peatland
- Encourages natural peat formation and carbon storage.
• Reintroducing sphagnum moss
- Boosts peat accumulation and habitat regeneration.
• Removing invasive species
- Prevents disruption to native peatland flora.
• Controlled grazing
- Manages vegetation growth to support ecosystem balance.
What does Anaerobic mean?
Anaerobic refers to conditions or processes that occur without oxygen.
How do anaerobic conditions affect the carbon cycle in peatlands?
Without oxygen, decomposition slows down, leading to carbon accumulation in the form of peat rather than its release as CO₂.
What happens to carbon when anaerobic conditions are disrupted?
Drainage or disturbance introduces oxygen, allowing microbes to break down organic material, releasing CO₂ into the atmosphere.
How do anaerobic conditions influence the water cycle?
Waterlogged environments limit evaporation and infiltration, preserving moisture and reducing runoff.
What non-peat ecosystems rely on anaerobic conditions for carbon storage?
Mangrove swamps and deep ocean sediments also trap organic carbon due to low oxygen levels.
