Date of Award


Degree Type


Degree Name

Bachelor of Science Honours


Faculty of Communications, Health and Science

First Advisor

Dr Jackie Alder


This thesis examines the environmental impacts of mountain bikes on trails in the southwest of Western Australia and the preferences, perceptions, trail use and demographics of mountain bike riders in that region. This information is important for resource managers and trail developers to ensure that the trails that are provided and planned for mountain bike use in the region are environmentally appropriate and acceptable to users. The environmental impacts were examined through biophysical studies, which investigated soil loss, soil compaction and vegetation damage on and adjacent to mountain bike trails over a period of six months. A mountain bike racing trail (Lowden, WA) and a trail designed for recreational mountain biking (Marrinup, WA) were monitored. A self-administered questionnaire was used to obtain information about user preferences, user perceptions, trail use and demographics. The results of these studies were integrated and the implications for trail design, conclusions and recommendations were derived. Overall, the biophysical studies found limited trail impacts, in particular there was little soil loss on the trails, few impacts on areas adjacent to the trails and no trail widening. Racing impacts differed from those of recreational riding. Occasional loosening of the trail surface and minor temporary damage to the adjacent vegetation were observed after racing and not on the recreation trail. Trail features (curves and straight stretches), slope and soil characteristics should be taken into consideration when designing a trail to ensure low erosion and maintenance. The main findings of the user survey indicated that mountain bike riders prefer natural settings and trails with a firm surface. They support a code of conduct and are aware of environmental and management issues associated with trail use. Differences have emerged between racing riders and recreational riders. Racing riders prefer technically demanding and challenging trails with downhill sections, curves and jumps, whereas recreation riders prefer trails that are less challenging, but are well marked and have drinking water provided. All riders agreed that more mountain bike trails are needed in the study area. This study concluded that mountain bike trails in the southwest of Western Australia can be environmentally sustainable and acceptable to trail users. Slope and soil characteristics must be major considerations in the siting and design of trails. Environmental impact can be minimised if trails are designed specifically for racing or recreational purposes.