In total there are more than 250 mountain bike routes in the Netherlands with a total length of more than 5,000 kilometers. Of these routes, 225 go through a protected nature reserve to a greater or lesser extent. The total area of disturbed nature reserve in the Netherlands is therefore 17,735 hectares, comparable to 25,000 football fields.
Karen Krijgsveld, researcher at Wageningen Environmental Research, conducts extensive research into human disturbance of birds. Last year, she and others published a hundreds-page report on the disturbance of birds through recreation for Vogelbescherming Nederland.
Mountain biking as a form of recreation is also discussed in that report. “The speed and unpredictability, especially in generally less crowded places, means that mountain bikers cause more disruption than other cyclists,” the researchers write. “Nowadays, forest trails are increasingly being built specifically for mountain bikers. While it leads to a further increase in trail density, it also prevents mountain bikers from cycling haphazardly through the forest, which is probably ultimately an improvement for forest birds.”
Then those mountain bike trails must be built close to existing trails in order to spare the still undisturbed parts of the forest, says Krijgsveld. “If a new mountain bike trail is built in a place where there is no trail yet, it will add extra disturbance to an area that is already very heavily disturbed.”