English summaries

English abstracts
volume 114
issue 3, May 2013

- Non perishable: recommendations for a new nature policy
- F. Berendse, B.H. van Leeuwen, B. Arts, T. Bade & S.M.M. Kuks
- The Dutch government asked the Council for the Environment and Infrastructure to provide an advice about a new nature policy plan. A small committee with representatives from science, agriculture, water management and trade and industry prepared this advice. The main conclusion of the Council is that the Nature Policy Plan of 1990 should be continued. A sufficient area of land and water and continuity of policy and management are the key factors that determine whether we will be able to provide a sustainable future for the diversity of wild plant and animal species in The Netherlands. Special attention is given to sustainable financing of the management of natural areas by linking the costs and profits that nature can deliver. The advice emphasises the need to maintain strong social support for nature conservation in the coming decades when the distance between people and nature will increase even further. For this purpose large investments are urgently needed, both in nature nearby densely populated areas and in nature education on primary schools.
- Towards a vital nature network in The Netherlands
- P.C. Schipper & A.C.P. van Montfort
- For every part of the Dutch national nature network we assessed three properties -robustness, resilience and biodiversity- in individual parts of the network in order to evaluate this nature network. The valuation takes place in two steps, first an estimation of the perspective was created by merging the aspects resilience and robustness. Ultimately, this leads to an appreciation of the EHS: areas of international importance, of national importance, or of regional interest.
  
  Marked regional differences between biodiversity and perspective of natural areas were found. Ten regions with large clusters of natural areas and robust regional networks could be distinguished. They are divided in two groups. Six regions have nature reserves with a predominantly positive perspective and four regions have nature reserves whithout favourable perspective. In these four regions a tension between nature conservation policy and water policy is the cause of the unfavourable perspective.
  
  The idea to use a network of nature reserves to protect nature is a good concept and still works. Evaluations of the nature policy however indicate that the 1992 biodiversity objectives were not achieved. The nature network has to be a vital network. So far the underlying processes in the landscape have been too little taken into account.
  
  The coastal area delivers the most important contribution to the national nature network, on the Pleistocene sandy soils large cores of natural areas with a favourable perspective occur, but in the lower part of The Netherlands -the river area, the fen area and seaclay areas- the perspective of many natural areas is unfavourable. This will place the functioning of the whole national network under threat, because the cohesion between nature reserves eventually will disappear.
- Effectiveness of nature conservation in The Netherlands
- J.P. Bakker & J. Wiertz
- The international responsibility for nature conservation interest in The Netherlands is concentrated in semi-natural landscapes, and hence requires active management to prevent natural succession to forest. Management of existing biotopes by grazing and haymaking and creating new ones by top soil removal and rewetting is often successful. Both are, however, also often frustrated by atmospheric deposition, acidification, drainage and fragmentation of abiotic processes and species interactions. Conservation efforts could be more effective when working at the regional level including groundwater flow, thus scaling up from locality to landscape and from species to food web. Within a nature reserve, a combination of management practices such as grazing, hay making and laissez-faire is most cost-effective.
- The use of environmental DNA (eDNA) to monitor biodiversity
- J.E. Herder, J.J.C.W. van Delft, E. Bellemain & A. Valentini
- Analyses of Environmental DNA is a new approach for monitoring biodiversity. The method is based on the limited persistence of the DNA left behind by species in their environment. This environmental DNA (eDNA) can be detected in water samples, thereby indicating or confirming a species’ presence. In this article we present an overview of the various habitats where eDNA has been successfully used for species detection. We show the results of pilot studies carried out in the Netherlands on the freshwater fish Misgurnus fossilis, dragonflies Aeshna viridis and Leucorrhinia pectoralis and the mammals Neomys fodiens and Microtus oeconomus. We focus on case studies in which eDNA has been used to monitor endangered species. Furthermore, we describe DNA metabarcording by which a list of species is generated from an environmental sample. Finally, we take a look into the future by suggesting areas where more research is needed. We think that this new tool can give an enormous boost to data collection both in monitoring and biodiversity studies, thereby contributing to the conservation of species.
  
  Analyses of Environmental DNA is a new approach for monitoring biodiversity. The method
  
  is based on the limited persistence of the DNA left behind by species in their environment.
  
  This environmental DNA (eDNA) can be detected in water samples, thereby indicating
  
  or confirming a species’ presence. In this article we present an overview of the various
  
  habitats where eDNA has been successfully used for species detection. We show the results
  
  of pilot studies carried out in the Netherlands on the freshwater fish Misgurnus fossilis,
  
  dragonflies Aeshna viridis and Leucorrhinia pectoralis and the mammals Neomys fodiens and
  
  Microtus oeconomus. We focus on case studies in which eDNA has been used to monitor
  
  endangered species. Furthermore, we describe DNA metabarcording by which a list of
  
  species is generated from an environmental sample. Finally, we take a look into the future
  
  by suggesting areas where more research is needed. We think that this new tool can give
  
  an enormous boost to data collection both in monitoring and biodiversity studies, thereby
  
  contributing to the conservation of species