Cold Enviroments Flashcards
Cold Environments : Polar conditions
- winter temp fall below - 50°C
- Low precipitation
- Permanently covered by ice (soil frozen)
- mosses and lichen found on the fringes of ice
- found at high latitudes 60° N/s
Cold Environments : Tundra environments
- less extreme than polar. Winter temps of -20C
- Summer may reach 3-12C
- High precipitation (snow) in costal regions
- soils are frozen (permafrost) but surface melts in the summer
- soils infertile (water removes nutrients)
- soils waterlogged (trapped due to permafrost and plants)
- low growing flowering plants (bear berry, artic moss)
- low bushes and small trees (in warmer regions)
Cold Environments : Polar animals (+ adaptations)
- extreme climate => less food = > few species
- polar bears and penquins
Cold Environments : Tundra animals
-less extreme climate => more food => more species’
I.E.
-mammals Artic fox, Artic hare,
-Birds such as ptarmigans
-Insects such as midges & mosquitoes in summer
Cold Environments : Permafrost definition
Zones of continuous permanently frozen ground. It is soil or rock that remains frozen in the summer months for two or more consecutive years
Cold Environments : Periglacial definition
the term used to refer to the process and landforms associated with the zones found within cold climates which are not permanently covered by snow or ice. Periglacial environments are defined by the presence of permafrost
Cold Environments : Factors affecting permafrost
- Climate => determines both temp & moisture. Main factor
- Proximity to bodies of water => water retaines heat better than land => warmer
- Slope angle and orientation => influences amount of solar radiation. I.E. South slope in N.hemisphere will melt faster due to more sunlight
- Ground surface => dark rocks absorb more light than lighter rocks
- Vegetation => insulates ground
- Snow coverage => white snow reflect sunlight
Cold Environments : Typical climate of periglacial enviroments
- Intense frost during winter, snow free ground in summer
- long winters
- climate has daily temperatures below 0C 9 months per year
- Temperatures rarely rise above 20C in summer
- Low precipitation <1000mm per year
Cold Environments : Cause of cold and dry conditions
- Low solar radiation due to high latitudes
- Large anticyclonic continental polar air masses keep the air dry
- low evaporation due to low temps
Cold Environments : Types of permafrost and their features
- Continuous => where ground consists of 100% permafrost. Mainly found within artic circle. Depths of 500-1500m
- Discontinuous => has patches of unfrozen ground. Under N/S facing slopes at N/S pole and water bodies. It is thinner and patchier than continuous permafrost
- Sporadic => Islands of permafrost. At the fringes of discontinuous permafrost. Under colder slopes (n/s in n/s poles) or under peat bogs which insulate. Only few metres thick, v. fragmented.
Cold Environments : Physical features of the tundra (6 points)
- Pingos (open system/closed system)
- Stone polygons and nets
- Extreme conditions of frost and waterlogging => impacts soil development
- In the summer, only upper (active) layers thaw => waterlogging as permafrost forms impermeable barrier
- Soil full of moisture => Solifluction (makes mudslides even in gentle gradients)
- Low oxygen concentrations in low lying waterlogged areas => development of peat
Cold Environments : Vegetation of the tundra (4 points)
- Tundra biome has low NPP (Net primary productivity) => <250g/m2/year
- Growing season is 3 months or less => plants adapted to low light conditions, strong winds and limited moisture
- Nutrient cycling is low due to cold temp
- No trees => some dwarf exist (Dwarf birch, only few centimetres high but spread wide across ground
Cold Environments : Animals of the tundra (3 points)
- short growing season => low food (+ extreme conditions) => low biodiversity
- Low diversity => fragile ecosystem (easily upset, does not recover well)
- summer months, insects emerge => provides food for breeding birds (v.few live year round in tundra)
Cold Environments : Adaptations of the polar bear (3 points)
Fur on soles of the feet <= better grip and insulation on permanent ice
Large body & small ears <= low surface area-volume ratio
Thick layer of blubber & hollow white fur <= insulation & camouflage
Cold Environments : Caribou adaptations (3 points)
Large spreading hooves <= easier to walk on snow or boggy ground
Thick coat of hollow hairs <= gives excellent insulation
Constantly on the move => prevents overgrazing thin soils
