Arctic Tundra carbon water

What are the yearly average temperatures

-15

Why is the tundra mainly treeless

Permafrost prevents trees from anchoring their roots

What is the NPP of the tundra

200g/m2/year

Annual precipitation of the tundra

50 to 350 mm per year

What are the outputs during summer months

Snow melt and active layer thawing - large amounts of water exiting, increase in river flow.

Small amounts of evaporation and sublimation

Why are winter outputs minimal

Temperatures stay below 0, so little meltwater and lack of biodiversity means minimal outputs there

Why is there little evapotranspiration

• Sparsity of vegetation and shortness of growing season (t)

• Majority of the suns radiation goes into melting the snow, and so ground temp. remains low and inhibits convection

• Surface and soil water frozen most of the time

Why is the atmospheric store of water low

Cold temperatures cannot hold much water (humidity)

What is the main store of water in the tundra

Permafrost

Why is the groundwater store minimal

Permafrost is a barrier for infiltration percolation and groundwater flow

When is there a temporary surface water store

In the summer months, as wetlands ponds and lakes form - when snow melts, but cannot infiltrate PF

How many seasonal lakes are there in alaska

Up to 3 million

Why is the tundra/permafrost one of the most significant carbon sinks in the world

As the permafrost holds partially decomposed plant matter - locked away since the Pleistocene.

How much carbon is in tundra soils/permafrost globally

1600 GT (or 50%)

Due to global warming, what is happening to permafrost and carbon

It is becoming a store rather than a sink of carbon - as it melts, it releases CO2

By how much is the underground store of carbon larger than above ground

5 times larger

Why is plant growth limited

Low temperatures, lack of liquid water and minimal nutrient content in the soil limits plant growth (and so little photosynthesis)

How much carbon is stored in vegetation

4 to 29 tonnes per hectare (less than 20%)

Why is there seasonal variation in carbon content in the vegetation

Growing season (3 months) - rapid growth and long daylight hours - increased carbon concentration.

How does the tundra regulate itself (increase of carbon)

As global temperatures rise, there is more plant growth in warmer months - counteracting the increased emissions of CO2 from melting Pf and balancing itself.

What are the physical factors that affect flows and stores in the water cycle

• temperature

• Relief

• Rock porosity

• Rock permeability

How does temperature affect the water cycle

below zero temps ensure that water is mostly frozen as ice - summer melting releases some stored water in the active layer (seasonal variation)

Barely any evapotranspiration in winter due to cold temperatures, so meltwater (if any) stays sitting on the land.

How does rock porosity affect flows and stores of the water cycle

• Poor drainage due to thick permafrost

• Rock/soil waterlogged through the year due to extensive glacial deposits.

How does rock permeability affect the water cucle

Igneous and metamorphic rock underlie tundra - and so make the land impermeable to water.

How does relief affect the water cycle

Largely flat landscape due to years of erosion - and so water sits on the surface as pools/lakes when it does melt

What are the 4 factors affecting the carbon cycle

• Vegetation

• Temperature

• Mineral composition of rocks

• Organic matter in soil

How does temperature affect the carbon cycle

Low temperatures slow fluxes - eg decomposition and respiration

How does vegetation affect the carbon cycle

Due to dry and cold climate, vegetation grows very slowly. Therefore, NPP and photosynthesis is low - and peak carbon from vegetation is in summer when days long and growth increases.

How does organic matter affect the carbon cycle

Carbon is mostly stored as partly decomposed matter in the permafrost. Low temperatures inhibit decomposition, and majority of the carbon is locked in permafrost.

How does mineral composition of the rock affect the carbon cycle

Low moisture and temperatures mean minimal weathering - and majority igneous and metamorphic rocks, so little carbon. Minimal effect on the cycles.

How much oil is in Prudhoe bay

25 billion

In what year was the oil discovered

1968

How has the albedo been lowered by human activity

Dust has been generated - increasing the absorption of insolation (heat)

How does oil drilling impact the water cycle

increased temperatures melt PF and snow cover, producing runoff and higher river discharges - flood risk.

How has construction impacted the water cycle

Digging for gravel and sands (construction materials) interrupts drainage, and creates artificial lakes.

How much permafrost thaw have artificial lakes sen in Fairbanks

15m

Why have river discharge rates fallen

Water has been abstracted (Taken out) for industrial use.

By how much have CO2 emissions increased in Alaska since 1975

73%

Carbon cycle in tundra in the SUMMER:

• Rapid growing season, photosynthesis and respiration - release of carbon

• Plants input organic matter containing carbon into the soil

• Microorganisms in soil become active; CO2 released into the atmosphere via respiration

Carbon cycle in the tundra in WINTER:

• pockets of unfrozen ground (talik) release CO2 and CH4 into the atmosphere

• Minimal microbial activity in winter months, as snow insulates and allows for decomposition - but generally, very little

• No/little plant growth and respiration

How much CO2 is released every year by PF melting

40 million tonnes

How much methane is released by PF melting

114,000 tonnes per year

How does industry release carbon

Drilling, oil spills and gas flaring all release excess CO2 and Methane

How does industry impact vegetation/carbon in biosphere

Vegetation is removed for human activity (building, drilling). Decrease in vegetation means less photosynthesis - less CO2 removed from the atmosphere. More decomposition occurs in melted soil, and so more carbon in the atmosphere.

What are the main management strategies implemented to help the biome

• Trans-alaskan pipeline (refrigirated supports and elevated pipelines)

• Gravel pads

• Lateral drilling (drilling sideways through a single point - reduces the amount of equipment required).

• Satellite tracking (from an arial view, detecting areas that contain oil and gas - reducing mass drilling in the area with no result.)