How do the water and carbon cycles operate in the Arctic Tundra?…
How do the water and carbon cycles operate in the Arctic Tundra?
Climate- cold and dry.
-8 months of the year are below freezing. In winter, temperatures are low as the sun is not over the horizon.
-Total amount of precipitation is around 100mm (TRF=2000mm). Nearly half of the total rainfall occur in 2 months.
Impact on Water Cycle: Too cold for evaporation and transpiration to occur. Low infiltration as ground is permafrost - although active layer thaws in summer and is then permeable. Low groundwater store as permafrost prevents infiltration, percolation,recharge and groundwater flow. River discharge is low as usually frozen but increases in summer as snow and ice melts.
Impact on Carbon Cycle: Little decomposition due to low temperatures.
Low photosynthesis and respiration as sparse vegetation. Sunlight is needed for plants to photosynthesise (often 24h darkness in winter).
Low store in biomass due to sparse vegetation cover
Low atmospheric store due to low temperatures and sparse vegetation preventing the flux of carbon to and from the atmosphere.
Large carbon store in permafrost where it can be trapped for over 500,000 years.
Tundra envrionments are located in the Northern Hemisphere.
Tundra is a type of biome where the tree growth is hindered by the short growing season and low temperatures.
flat and gently undulating due to former ice sheets eroding the land.
Impact on Water Cycle: Surface storage will be high as ground is impermeable and cannot infiltrate.
Active Layer - seasonal thawing of the surface ground Permafrost - permanently frozen ground for at least 2 consecutive years
Talik - the unfrozen ground that lies below the permafrost and between the actve layer and the permafrost
Impact on Water Cycle: permafrost is impermeable so there is little infiltration
Snow melt and thawing of the active layer increases surface storage.
Impact on Carbon Cycle: large carbon store in permafrost as microbial activity cannot occur in the cold temperatures.
the permafrost will remain a carbon sink because increased plant growth (due to warmer temperatures) will lead to more photosynthesis so reducing the atmospheric store of carbon.
the thawing of the permafrost releases carbon dioxide and methane by composers and so global temperatures increases. the permafrost continues to thaw and GHG concentrations continue to increase.
Limited growth due to low temperatures and short growing season. Mainly mosses
Impact on Water Cycle: very little transpiration
Impact on Carbon Cycle: low amounts of carbon stored in above- ground biomass, Carbon stored in roots in permafrost.
In Summer - Carbon Sink - carbon is taken in by photosynthesis
In Winter - Carbon Source - little intake of carbon as sparse vegetation and 24h darkness (so little/no photosynthesis). Snow cover insulates the ground allowing for decomoposition and unfroxen ground like lakes alos relaease Carbon.
Oil and gas were discovered in Prudhoe Bay on the North Slope of Alaska in 1968. It is the largest oil and gas field in North America.
TAPS - The Trans- Alaskan Pipeline was built during the 1970s from Prudhoe Bay in the North of Alaska to Valdez in the South. Sea ice in the BEaufort Sea meant it was too dangerous for tankers to access the port to transport the oil, so a pipeline was required.
Water Cycle Stores surface store will increase due to the thawing of the permafrost.
Biomass store decreases when vegetation is removed for construction.
Water Cycle Flows: In summer, wetlands, ponds and lakes become more extensive increasing evaporation.
Increased run-off due to melting of the permafrost
Carbon Cycle Stores: atmospheric store decreases due to the removal of vegetation
biomass store decreases as vegetation is removed for construction
soil store decreases due to the thawing of the permafrost which releases CO2 to the atmosphere.
Carbon Cycle Flows: Photosynthesis and respiration decreases due to removal of vegetation
increased respiration by decomposers
due thawing of the permafrost
Building on piles allows cold air to circulate between the ground and the floor of the building.
Building on aggregate pads substitutes the insulating effect of vegetation and reduces he transfer of heat from the building to the ground.
Drilling laterally beyond the drilling platform - oil and gas can be accessed several kilometeres from the driliing site so fewer drilling sites need to be created
TAPS pipeline has special insulation coating 10cm thick to ensure minimal damage to the permafrost.
Built abover ground so warm oil
) does not thaw the permafrost