Artic tundra

• Negative heat balance for 8-9 months of the year
• Mean temperatures of -15 degrees but can get as low as -40 degrees in the deepest winter
• Precipitation is low at about 50-350mm per year which is only 10% of what there is in the Amazon
• Short growing season of 50 days in which most plants grow up to about 15cm
• Most of tundra formed from Precambrian igneous rock = low permeability = standing pools of water in the warmer summer
• NPP is very low at only 200g/m2 per year = 16x slower than the rainforest
• The biomass carbon store is 4-29 tonnes per hectare
• Very small vegetation biomass store of only 0.6kg/m2 = 75x less than in the rainforest
• Less than 20% of carbon id stored in its plants in the tundra
• Active later is inactive for 315 days of the year (86%)
• Permafrost is a carbon sink as stores over 1600 gigatons (5/6 of all carbon in the tundra)
• Permafrost is full of DOM which has not been touched for 1000s of years
• 3.2x more carbon in DOM than in the plants above it
• Rate of decomposition is dependent on latitude = further north = slower decays e.g. North Canada
• Central Siberian plane (Russia) has flat land = vast amounts of carbon in the soil; low relief and elevation = thicker soil = more carbon