Fragmentation and Road-Infrastructure in The Netherlands: From History to Future

G.J. (Hans) Bekker

In the highly populated Netherlands, intensive landuse and a huge road network have resulted in a highly fragmented landscape. The impact on several fauna species is great. In the 1970s, action groups began to ask for attention to be given to the problem of fragmentation by infrastructure. The first measures taken along motorways were for the badger Meles meles, an endangered species in the Netherlands. Much has been learned during this period about the process, the technical and ecological possibilities, and the approach to defragmentation in the Netherlands. The experiences are used in policy, research items and a wide variety of measures. Some of these learning points are described in this paper. The process included much discussion and it appears that people from different disciplines need each other. Communication between and information to all participants of the process are vital. Various authorities have translated the experience into objectives and programmes. The policy now in the Ministry for Transport, Public Works and Water Management is to avoid from the start any new fragmentation. Where avoidance is impossible the damage by fragmentation should be mitigated, and when mitigation is not enough, the loss of nature must be compensated. A range of measures has been implemented: simple pipes, redesigned culverts, ecoducts and so named walls of tree-stumps as a modification to existing constructions beneficial to animals. Some measures became a standard feature in the design of new roads, while special projects were set up to equip existing roads with these facilities for all kinds of species. At the moment there is a plan until 2002 to avoid problems and to solve the main problem points caused by existing roads. Research is necessary to realize these measures. Research concerning the impact of roads and traffic on all kinds of species is needed to predict the effects in EIAs and to translate the ecological knowledge into methods and measures. It is a fact that most of these measures are used by animals: tracks have been seen on sand beds. The effectiveness of measures on the development of populations of target species around a new highway is unsure. It is obvious that an evaluation of the policy must also be carried out.

Keywords: Habitat fragmentation, mitigation, compensation, badger pipes, ecoducts, road infrastructure