The Tundra Flashcards
location of tundra?
8 million km2 in northen canada, alaska and siberia
what is the climate like?
climate conditions in the tundra are sever
8/9 months a year the tunda has a negative heat balance
ground is permanently frozen with only top layer or so thawing durin the arctic summer
what is permaforst?
permafrost underlines much of the tundra and is a key feature of the regions water cycle
whats the winter link?
sun remains below the horizion and temperatures can get below -40 degrees
whats the summer like?
long day light hours, growing season
what are levels of precipitation like?
always low 50-350mm per year mostly snow
whats the biodiversity like? (plants and animals)
few plants and animals adapted to these conditions
biodiveristy is low
ecosystem is treeless
is there much water in the atmosphere?
no
why is transportation low?
sparsness of vegetation cover and short growing season
why is evaporation low?
much of the suns energy is melting snow so groundcover remains low
what is permafrost a barrier to?
infiltration, percolation, recharge and groundwater flow
when is there a sharp increase in river flow?
melting of snow, river ad lake ice and the most active layer of permafrost so in spring and early summer it means that there is a sharp incraese in river flow
what does the increase in river flow do?
extensive wetlands, ponds and lakes on the tundra durin summer- temporary store of liquid water due to permafrost which impedes drangidge
is permafrost a carbon sink or store?
vast carbon sink
how much cabon is the tundra estimated to store?
1600 GT of carbon
why is there so much carbon in the tundra?
accumulation of carbon is due to low temps which cause slow decomposition of dead plant material.
how much greater is carbon stored in the tundra soil then above ground biomass?
x5
whats a carbon flux?
summer months the active layer thaws
how does the carbon cycle change?
durin growing season tundra inputs carbon rich litter into the soil
in the summer activity of the micro orgnisms incraese relasing c02 into the atmosphere
in the winter pockets of unfrozen water and soil in the permaforst act as a source of carbon dioxide and methane
what is the fear around the tundra?
that due to global walming and vast menting the huge carbon sink will eventually become a carbon store
what allows so decomposition to take place?
snow cover
however what might insure that the tundra doesnt become a carbon store?
higher temp stimulate vegiation growth incraesing upatke of CO2
what are flow are stores in the tundra influenced by?
temperature, relief, rock permeability
impact of meltwater
forms million of ponds and shallow lakes
why is drainage poor?
water cannot infiltrate the soil because of permafrost depth
impact of low growing season?
photosynthesis and net primary production (NPP) are low because growing season only lasts three months
oil and gas production
oil and gas were discoverd in the tundra at prudhoe bay, by the early 1990s the north slope accounted for nearly 1/4 of the USA’s dometsic oil production
impact that production has
-permafrost is highly sensitive to changes in the thermal balance
-construction and operation of oil and gas instillations and infustratcure diffusing heat directly to the environment
-dust along the roadside creates darkness on snow surfaces therefour increasing absorption of sunlight
how do gas and oil spillages impact?
imput co2 into the atmosphere, destruction or degrading of vegitation reduced photosysnthis ect
slow growing nature of the tundra means that recovery may take years
-flooding more likley due to melting
-strip mining creates artifical lakes wich disrupts dranige and exposes permaforst
managment
-inslated ice and gravel pads to directly protect the permafrost
-building and pipelines on evaluated piles, this allows cool air to circulate beneth these structures
-drilling latterally, this allows oil and gas to be assessed from sevrel km away therefor fewer drilling sites are needed
-technology, powerful computers can more accurately detected where the oil is meaning that they don’t have to have so many drilling sites
-refrigerated support - used on transatlantic pipeline to stabalise temp of permafrost
