Given the particular aspect of a very slow rate of vegetation growth and regeneration, if polar and alpine tundra is disturbed, serious consequences may result, especially during late spring and summer when the surface layers are thawing. During this time vegetation, particularly on sloping ground is vulnerable to disturbance and erosion through run off. Tundra is vulnerable to trampling, especially from vehicles, oil spills and overgrazing. In winter problems arise from compaction of the snow cover from trampling, by skiers and skidoos and other vehicles, as compacted snow does not protect the vegetation like natural snow cover and can cause a shortening of the growing season as melting regimes in the spring are altered. Mining and its associated activities are a threat to the Tundra regions.
Tundra occurs mainly in the northern hemisphere (20 million Km2), covering a probable 20% to 25% of the earth's land surface.