Is mountain biking environmentally harmful?

A brewing controversy in Cleveland Metroparks:should an agency whose mission is to conserve natural resources allow mountain biking?

Is this outdoor recreational activity more destructive than paved trails, natural surfaced trails that are poorly placed, or equestrian trails? Cleveland Metroparks in this case is coming down against the idea of mountain biking. Meanwhile National Park rules may change to allow mountain biking.

Having been around parks for many years, and seeing many different types of trails and activities, my personal opinion is that if properly managed, this type of trail is just as compatible with natural resources conservation as a bridle trail, paved trail, or even hiking trails with natural surfaces.

Bicycles can undoubtedly cause erosion issues, but so can other unregulated uses. People need to be in contact with nature. If mountain biking excites them, they ought to be able to engage in their chosen outdoor recreation. Bike trails can be created in an environmentally sustainable manner. As long as it is done right, I am all for it.