Avalanches can be effected on land by snow banks in you backyard.
Effects of Avalanches: The effects of an avalanche can be destruction of buildings/roads (e.g. ski lodge), Death or injury of person (frostbite, broken limbs etc.), Death or injury of animals...
Loss of life, damage of property, disrupt transportation corridors. In a severe winter, avalanches can close mountain highways!
The effects of an avalanche can be loss of animal habitats, people on snowboards or snowmobiles can be killed... and there could be loss of trees
If it is biodegradeable, then it just becomes "part" of the land. If it is not biodegradeable, it justs sits there.