Analysis of the geo-environmental effects of Trail races and MTB races within the scope of the Garrotxa Volcanic Zone Natural Park, Girona

Abstract

Sports activities developed in natural environments have proliferated in recent years. Trails and races for mountain bikes (BTT) and mountain races within protected areas are some of the most recent activities and little is known about the geo-environmental impacts they can generate. In this work, the impacts of two activities, of this type that are carried out within the Natural Park of the Garrotxa Volcanic Zone have been analysed. The race that runs through the heart of La Fageda and the Tramun (BTT) race. 10 control stations (EC) were established at different points along the routes, 5 for each type of race. In each EC, the rates of soil erosion, transfer and compaction, stoniness, stick marks, ruts and the uprooting of vegetation were measured, before and after the races. The ECs that presented higher erosion values were those located on steep slopes, narrow sections and poor and unstable soils, with small, unconsolidated informal corridors and with continuous processes of soil loss and uprooting. No significant erosion impacts were observed on consolidated tracks and paved roads. On the other hand, in the tracks opened by the races or in unstable tracks, both in terms of soils and steep slopes, an erosion that is difficult to recover due to natural processes has been generated, with soil losses, slope instability and impact to the vegetation.