The effects of rock climbing on cliff‐face vegetation

Abstract

AbstractQuestionWhat are the effects of rock climbing on diversity, abundance and composition on cliff‐face vegetation along environmental and use gradients typical of modern climbing?LocationNew River Gorge National River, WV, US.MethodsWe compared species richness, abundance and composition of vascular plants, bryophytes and lichens on 79 pre‐established rock climbs and 32 unclimbed ‘control’ sites across potential climb‐use intensity and cliff structure using linear models, residual analysis and NMDS ordination.ResultsDifferences in species richness and abundance associated with potential climb‐use intensity and cliff structure were variable across taxonomic groups. Linear models indicated that cliff angle was the strongest explanatory variable of species richness and abundance for all three taxonomic groups. Once the effects of biophysical variables were modelled, analysis of the residuals indicated that potential climbing‐use intensity had a small but negative effect on species richness and abundance of vascular plants (range 3–6%), no effect on bryophytes (0%) and a substantial effect on lichens (range 10–12%). Similarly, NMDS ordination indicated that cliff angle, canopy height and aspect were the primary drivers of species composition. We observed no change in community composition due to climbing.ConclusionsOther studies have observed significant impacts of climbing on vegetation at the base of cliffs. Here, we observe that potential climbing‐use intensity has some impact on species richness and abundance of vascular plants and more significant impacts on lichens, however cliff angle is a fundamental control on cliff vegetation. Because of the challenge in sampling steep and overhanging cliffs, we recommend that climbers be directly involved in the assessment, monitoring and management of cliff resources in order to ensure that the full range of biophysical conditions of cliff ecosystems are considered.