Visitor Impact Monitoring: What, Why, and How?

Eroding trail treads, denuded campsites, stressed wildlife, and damaged tree saplings are some common signs of visitor-induced resource impacts in national parks and other protected areas. From an areal perspective, most visitor impacts add up to only a small fraction of park areas and as a result typically impinge on few plants or animals. However, such impacts are a legitimate management concern since they often affect areas that are ecologically or culturally significant—the very reason these places were designated as part of the protected area system in the first place. Although not necessarily widespread, biophysical impacts at the site level are often intense, consequently affecting the quality of visitor experiences and incurring maintenance costs.In addition, since recreation sites and trails are often dispersedly distributed, some forms of visitor impact, such as trail degradation, dispersal of invasive species, and wildlife disturbance, can have landscape-level effects (Knight and Gutzwiller 1995; Hammitt and Cole 1998; Buckley 2004)