Effects of rock climbing on the vegetation of the Niagara Escarpment in southern Ontario, Canada

The cliffs of the Niagara Escarpment support unique and diverse plant communities. Although recreational rock climbing has become extremely, popular in North America over the past two decades, little is known about the effect of this sport on the natural biota. We examined the ecological effects of rock climbing on vascular plant, bryophyte, and lichen communities along the Niagara Escarpment in southern Ontario. We made comparisons among randomly, selected climbed and unclimbed rock outcrops by, sampling from three positions: plateau (or cliff edge), cliff face, and talus (or cliff base). Density,, percent cover, species richness, and species diversity, of vascular plants were lower on climbed outcrops than on unclimbed outcrops. In addition, the proportion of alien plants was three times greater in climbed areas than in unclimbed areas. The frequency and richness of bryophyte species were also significantly, lower in climbed areas. The frequency, of lichens was the same on climbed and unclimbed cliffs, but species richness was significantly, lower in climbed areas, and community, composition differed between climbed and unclimbed areas. Our results suggest that rock climbing has significant negative effects on all aspects of the vegetative community, on cliffs. Therefore, we recommend that conservation plans be modified to include specific Policies regarding recreational rock climbing for lands containing exposed cliffs. For example, we suggest that the establishment of new climbing routes be banned in protected areas along the Niagara Escarpment.