The Haut-Jura forests are not threatened but they are the object of multiple attentions to avoid the decline, in the long term, of certain species and certain forms of forests. The forest biodiversity is, in fact, a victim of the disappearance of very old trees and of dead wood as well as of the development of the wood industry (energy, construction). Clear cuts can locally condemn the presence of forest habitats and remarkable species. As for the multiplication of the accesses to the forest heart for timber extraction, it opens up dangerous breaches for motorized sports.