Living world 3:

Where are cold environments?

covers 1/4 of earth. High latitude regions where cold, sinking air generates freezing winds and sunlight is low.

Mc Murdo, Antartica

very less annual rainfall. Low precipitation, 10mm-25mm each month. Lowest in October, Highest in June. Very cold, Lowest in August, highest in january

Barrow, Alaska

Very less annual rainfall. between 10-30mm each month. Lowest in March, Highest in August. Lowest temp in January, Highest in August.

Layers of soil in cold environments

active layer, permafrost, talik

Active layer

ground 25cm down, frozen in winter, thaws in summer

Permafrost

ground at/below 0 degrees for atleast 2 years. 25-100cm down. Solid and plant roots rarely penetrate it.

Talik

Unfrozen ground found below/within permafrost. Able for plant root growth.

Where is permafrost found?

Artic regions, greenland, Alaska, Russia, china. covers 22.8 million km^2 in earths N hemisphere.

Types of permafrost distribution

continuous permafrost, discontinuous permafrost

Continuous permafrost

continuous sheet of frozen material, Extends under all surfaces except large bodies of water in the area.

Discontinuous permafrost

broken up into separate areas. Some permafrost in shadow of a mountain/thick vegetation stays all year. In other areas, summer sun melts the permafrost for several weeks/months

Melting permafrost

warmed by 6 degrees during 20th century. leads to rising of water levels, increased erosion. erosion occurs when permafrost melts bc soil & sediment easily washed away w/o ice binding them together.

How plants are adapted to tundra environments

food web= producer species like low lying shrubs/mosses/lichens. Biotic & abiotic components are interdependent, low lying vegetation helps protect soil from wind erosion.

Tundra plant adaptions

permafrost, poor drainage, low insolation, strong wind

Permafrost tundra plant adaptions

- permafrost chills the ground & barrier to root growth, plants with shallow root systems survive.

Poor drainage tundra plant adaptions

- Poor drainage- summer melts active layer leaves places waterlogged, hardy organisms can survive extremely dry and wet conditions, allows them to cope with seasonal changes

Low insolation (exposure to sun rays)

- high latitude, light weak. Plants maximise photosynthesis; photosynthesis immediately starts bc plants don't need time to regrow their leaves.

eg= snow buttercup & artic poppy produces flowers very quickly, cup shaped flower faces up towards the sun.

Strong wind tundra plant adaptions

high air pressure = strong wind that blast tiny ice particles. Minimising transpiration loss to wind. Plants grow close together & near ground level/ Allows plants to trap particles of warmer air.

What is a tundra?

tree-less plain, located at polar areas at the top of the coniferous areas (don't lose their leaves in autumn).

Conditions in tundras

cold, dry, -33 degrees in winter, -3 to -8 degrees in summer, permanently frozen ground

Adaptions in tundra environments

barberry plant= shallow roots (permafrost), grows close to other plants, no trees.

Artic fox= thick coat for insulation, fur on paws, wraps tail around face/mouth, varied diet.

Musk ox= 2 layers of fur (long to protect from cold, short to trap warmth). Large/hard hooves to break ice, travels in packs.

Sami people in Alaska

experts of fishing, rear reindeer for transportation/clothes/antlers/meat, they move their houses to go to less harsh areas with more food.

Location of Alaska

NW of canada, 2million km2.

History of Alaska

Indigenous people= Inupiat & Yup'ik tribes, part of Inuit. During ice age, moved to Russia & Scandinavia, when they were joined to USA by a land bridge.

Types of opportunities in Alaska

Fishing industry, Mineral extraction, Energy, Tourism

Fishing industry =

there are 3000rivers, 3million lakes, 10686 km of Alaskan coastline.

Commercial fishing= employs 1 in 10 alaskans. Biggest fisheries in Alaska. provides 78500 jobs, adds 6 billion USD to state economy.

subsistence fishing = Native americans remain dependent on fishing for food, etc.

Mineral extraction=

1/5 states mning wealth from gold. Mines must be managed properly to minimise environmental impacts, toxic chemicals like mercury, cyanide & nitric acid. No dirty gold campaign, 50 businesses supported it; didn't buy pebble mine gold

Energy=

50 HEP supply alaskans with 1/5 of their electricity. Geothermal energy used in tectonically active parts of Alaska.

Tourism=

attracts 1-2 million annually. 60% of visitors in summer. Historical sites of Inupiat and Yup'ik heritage

types of challenges in Alaska

Climate, accessibility, buildings& infrastructure

Climate=

permafrost & short thermal season rule out crop production. Inupiat and Yup'ik coped with cold by making coats caribou skin & seal skin boots.

No settled population in Northern Interior; low temps & months without sunlight.

Accessibility=

physical processed make roads use difficult & dangerous.

Solifluction= in the summer, soil's active layer flows downhill, large amounts of soils & mud collect at the base, covering highways, cutting places off for months.

Over time, seasonal melting & re-freezing of active layer causes expanding of uneven ground surface called thermokarst.

Frost heave= pebbles & stones rise upwards to the ground.

Buildings and infrastructure=

Active layer melting, heat that building create can melt active layer. escaping heat from underside of houses led to many houses subsided. Millions of permafrost km2 damaged.

Houses built on pliers lift houses to prevent melting of active layer. pliers sunk deep into the ground.

Solutions for challenge of buildings and infrastructure

- roads built on gravel pads 1-2m deep to stop heat transfer from taking place. Utilities carried by utility corridors. Airport runways painted white to reflect sunlight to stop them from warming up on sunny days.

Alaska oil pipeline

800km trans-Alaskan oil pipeline, transports oil to Southern coast port of Valdez. 5 yrs to build. 8 billion USD to build.

Modification of the pipeline

raised of the ground on stilts 11m deep. pipeline suspension bridges to cross rivers.

Costs of the Pipeline

Bay locals only take 400 of 2000 jobs available. Oil tankers cause oil spills. 1989, oil spill skilled 5000 sea otters, seals, and eagles. Conflict with Native Americans.

Benefits of the pipeline

100,000 jobs, 1 in 7 Alaskans. Oil and Gas contributes 40 billion USD to annual state earnings. 90% of taxes raised comes from this. Route of trans-Alaskan pipeline runs underground to not disturb migration routes of tundra caribou. Pipeline insulated to protect it from freezing.