MITIGATION MEASURES TO REDUCE HABITAT FRAGMENTATION BY RAILWAY LINES IN THE NETHERLANDS

Rail infrastructure contributes to the fragmentation of wildlife habitats in the Netherlands. Plans for a large-scale extension of the Dutch railway network and an intensification of track use have made this problem even more serious. The most important fragmentation effects of railway lines for fauna are the loss of habitat, mortality, barrier formation and disruption in general. As a result habitats are reduced or become isolated from each other. This means that the chance of survival of (sub)populations is decreased. A large range of measures may contribute to a reduction of the fragmenting effect of rail infrastructure. These measures, as this article shows through practical examples, include: a restoration or development of a (substitute) habitat, placing wildlife fences as protection against railway lines, constructing fauna passageways and sound-reducing provisions. Railways also offer opportunities for defragmentation. By taking nature-oriented measures along railway lines, they may have the function of habitat, refuge or corridor. Mitigating measures in rail projects are on the one hand aimed at minimizing the fragmenting effect of railway lines, and on the other hand at utilizing the opportunities for defragmentation in an optimal way. The knowledge regarding the precise scale of fragmentation by railway lines in the Netherlands is still incomplete. A study that was started in 1996 will have to fill this gap in expertise.