P1 - Unit 1B - Cold Environments Flashcards
What are features of a polar environment?
- Greenland and Antarctica
- found at high latitudes 66.5°N and 66.5°S
- partly or completely covered in glaciers and ice sheets
- average monthly temperature is always below freezing which allows snow and ice to accumulate over time
- winter temperatures often below -50°C
What’s the features of tundra environments?
- found south of the arctic circle in the northern hemisphere
- land isn’t permanently covered by snow or ice but winter temperature -34°C
- Northern Alaska, Northern Scandinavia, Northern Canada and Northern Russia
- during the short summer, low lying shrubs and mosses grow in the active layer
What’s the active layer?
The top layer of soil in an area where permafrost is present. Each summer the icy soil briefly melts before refreezing.
What’s latitude?
A line drawn from west to east on a map showing where places lie relative to the equator and poles.
What’s permafrost?
Permanently frozen ground, found in polar and tundra regions.
What’s temperature range?
The difference between the highest and lowest over a period of time.
What’s Thermal growing season?
The period of time when temperatures are above 6°C and plants can grow.
What’s Tundra?
The flat, treeless Arctic regions of Europe, Asia and North America. Lichen, moss, grasses and dwarf shrubs can grow here.
What are the characteristics of tundra climates?
- high pressure, dry climate, low temperatures all year round
- summer max between 5-15°C winter -40°C
- below freezing 8-9months of year, growing season 6-7weeks
- sun remains low in the sky, 24hours daylight in summer, 24hours of darkness in winter
- annual precipitation low under 250mm
What are characteristics of tundra soils?
- Gley soils
- small amounts of dead vegetation decay very slowly due to low temperatures and limited moisture
- permafrost below limits drainage so soil is waterlogged in summer
- cold conditions restrict bacteria action causing peat to accumulate
In cold environments why is soil relatively low in nutrients?
Few decomposers can live in the cold climate so little dead organic matter is broken down so fewer nutrients are returned to the soil.
Why do herbivores like the caribou migrate?
In the summer they go north cause it’s the growing season and in winter they go south to get vegetation when it’s not available north
How does tundra plant cover affect the permafrost in the summer?
Plants growing on the surface absorb solar energy, protecting the permafrost and preventing it from thawing. The permafrost keeps melted water near the surface, where plants need it.
How could damage to tundra vegetation affect world climate?
-Tundra is one of the earths three major carbon sinks because during the short summer plants take in CO₂ for photosynthesis. Plants normally give of CO₂ when they decompose however because of the long, freezing winters plants can’t decompose quickly so they remain there for thousands of years which is keeping the CO₂ out of the atmosphere. However as the tundra melts this is at risk.
Why do cold environments have low biodiversity? And why are only a small amount of mammal species supported by the tundra environment?
Because it takes very specific traits to survive in the climate. This low biodiversity leads to species being at threat if just one change happens in the food chain.
Mammals need a lot of energy just to live and hunt and there isn’t tonnes of producers at the bottom of the food chain so when you get to the top there’s even less energy.
