All parts of the polar regions (climate, soils, water, plants, animals and people) are depedent on each other. If anyone of them changes, everthing else is affected.
- Cold, dry climate means low biodiversity in both the Arctic and Antarctica
- Ocean currents and wind create gaps in the sea ice which increases light levels in the water. This means algae and other producers can produce more food causing populations of fish (e.g. cod) to increase which then supports consumers such as seals, penguins and polar bears.
- If temperatures increase (e.g. due to climate change) more sea ice melts in the summer. Animals such as seals and polar bears rely on sea ice for breeding and hunting so if it disappears these animals are threatened.
- In the Arctic tundra, cold temperatures cause plants to grow and decompose slowly. This means the soil is low in nutrients further reducing growth rates. In the summer, the surface layer of the soil thaws and plant cover increases. Plants absorb heat from the sun and prevent the permafrost below from thawing. Slow melting of the upper layer provides liquid water for plants.
- In Antarctica, there are very few plants. Phytoplankton in the sea are the most important producers and form the basis of all food chains. (e.g. phytoplankton > krill > fish > penguins). Phytoplankton depend on nutrient-rich currents of seawater rising to the surface from deep underwater; if this doesn’t happened the whole ecosystem would be threatened.