BRAINCAKELong-term Carbon Sinks
Some carbon is locked away for thousands to millions of years in long-term carbon sinks. These form when dead organic matter is not fully decomposed, or when carbon is built into rock.
Peat forms in bogs where waterlogged, cold, acidic conditions keep oxygen out. Because conditions are anaerobic, saprobionts work very slowly, so partly decayed plant material, mainly sphagnum moss, builds up faster than it decomposes. Peatlands cover only about 3% of the Earth's land but hold more carbon than all the world's forests.
Fossil fuels (coal, oil and natural gas) formed from organic matter buried under sediment millions of years ago. Heat and pressure over long periods turned it into hydrocarbons. Coal formed mainly from ancient swamp plants; oil and gas formed mainly from marine plankton.
Sign in free to see the rest of this lesson, the R.E.C.I.P.E. recall steps and the quiz
BrainCake is free. Make an account in seconds and pick up where this page stops.
More in The Efficiency of Ecosystems
- The Limitations of Efficiency Calculations
- Energy Transfer and Food Chain Length
- Nutrient Recycling
- Conditions for Recycling Nutrients
- Microorganisms in the Nitrogen Cycle
- Microorganisms in the Carbon Cycle
- Short-term Carbon Sinks
- Human Influence
All 20 lessons in The Efficiency of Ecosystems · All Edexcel A-level Biology topics