Trampling by Humans and Animals

Pedestrian trampling has been known to favor select elements of affected vegetation types (in particular, grasses) for at least 200 years in Europe, although in comparison to vehicle disturbance, relatively small areas are affected. Pioneering field botanists, such as the late Nicholas Polunin, reported similar responses in the Arctic. During investigations of Inuit settlements on Baffin Island in the early 1930s, he observed that "the sealskin tents of the settlement are pitched on slight, bouldry slopes near the water, the most notable feature . . . being the virtual lack of higher vegetation on the much trampled areas between the tents, and the grassiness of the terrain in most areas around" (Polunin, 1948). Despite the small scale, these effects can persist indefinitely. In terms of species composition, campsites last used c.800 years ago differ little from contemporary settlements.

Polunin also noted analogous impacts from ungulate grazers: "Away from the settlement, caribou may eat and trample the more luxuriant lichens in healthy areas during their winter feeding, which may result in such a degree of denudation that the plants take many years to recover" (Polunin, 1948). Similar effects have been well documented in other parts of the Arctic to the effect that both humans and animals (in particular, caribou (Rangifer spp.)) have had significant immediate and lasting effects on vegetation and soils. In some areas, such as Iceland, heavy grazing by sheep and horses has led to massive desertification over the centuries. More recently, large numbers of semidomestic reindeer in northern Fennoscandia and northwest Siberia have raised concerns about potential overgrazing.

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