Vegetation changes at sub-xeric urban forest edges in Finland – the effects of edge aspect and trampling

Abstract

The relative strengths of the effects of forest edges and recreational use on understorey vegetation were studied at sub-xeric boreal urban forest edges in the greater Helsinki region, Finland. The study was performed at northern, eastern, southern and western edges, and vegetation sample plots were placed on, next to and away from paths with different trampling intensities 0–107 m from the forest edges. We found that human trampling altered vegetation more than the effects of forest edges. Vegetation changed dramatically on paths and the effects of path edges were seen in seemingly untrampled vegetation at least up to 4 m from the path edge. However, our results suggested that the effect of the edge may penetrate up to 50 m into forest interiors. Changes in vegetation composition indicated that the effects of the edge were stronger at eastern, southern and western than at northern edges.