Indirect Impacts of Soil Trampling on Tree Growth and Plant Succession in the North Cascade Mountains of Washington

The purpose of this study was to establish what effects soil trampling impacts may have had on tree growth and plant community succession at subalpine elevations in the North Cascade Mountains of Washington. While soil penetrability of an impacted site was not different from that of control sites, other soil characteristics were significantly different. Species diversity was greater at the impacted site, which was characterized by associations between soil characteristics and vegetation that were unlike those found at control sites. Mixed ordination analyses of the floristic and soil data indicated that past trampling impacts on soils may have had long-term effects on the successional development of the plant community. The impact of turn of the century mining operations on tree growth was significant at the time of impact but had no long-term effect after mining activities ceased. Recommendations for the management and reclamation of disturbed sites at subalpine elevations are given.