Water and carbon cycles in the Arctic tundra
- Created by: Katariina
- Created on: 22-12-21 16:52
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- Water and carbon cycles in the Arctic tundra
- Water cycle in the tundra
- Stores
- Limited groundwater and soil moisture stores. Permafrost is a barrier to infiltration, perco-location, recharge and groundwater flow.
- Snow and river/lake ice accumulates in the winter months
- In the summer, extensive temporary wetlands, ponds and lakes develop because permafrost impedes drainage.
- Flows
- Precipitation: 50-350 mm (low), most as snow
- Limited transpiration because of sparse vegetation / short growing season
- Low rates of evaporation. Most of the Sun's energy in summer is expended on melting the snow. In winter, surface and soil water are frozen.
- When ice/snow and active layer of permafrost melts in the summer, river flow increases sharply
- Stores
- Carbon cycle in the tundra
- Flows
- Carbon flows in the summer months (mostly) when the active layer thaws
- Respiration: the activity of micro-organisms increases in the summer, releasing CO2
- In the winter, pockets of unfrozen soil and water in the permafrost act as sources of CO2 and CH4
- Snow cover may insulate microbial organisms and allow some de-composition
- Stores
- Permafrost is a vast carbon sink: contains 1600 GT of carbon
- Global warming: a source of carbon?
- The amount of carbon in tundra soils is 5x greater than in above-ground biomass
- During the growing season, tundra pants input carbon-rich litter to the soil
- NPP is less than 200/grams/m2/year
- Small biomass: 4-29 tonnes/ha
- Permafrost is a vast carbon sink: contains 1600 GT of carbon
- Flows
- Water cycle in the tundra
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