Nature conservation should be concerned with the wider sustainable processes

and conditions in ecosystems rather than being narrowly fixated on some species of special interest. Together, the five regions containing unique species cover about 40% of the country’s surface. This fact does not imply that the other 60% has no conservation value. For example, few of the characteristic species traced in this study are exclusive to a single region; most of them also occur, though rather sparsely, in other parts of the country. Following the methodological principles of robustness and generalizability, we looked for congruence across the distribution patterns of five species groups and selected only those regions where at least two of the groups were represented. As a consequence, the riverine region in the south of Gelderland for example, was not included in our selection;

KPT-8602 although it contains several characteristic moss species. The TSA HDAC supplier number of characteristic species in each region varied. The small LIMB region hosts by far the highest number of characteristic species. However, the species occurring there are not of great international importance. Being submarginal species in the Netherlands, their distribution is much larger in southern or central Europe. The FEN region, in contrast, is not characterized by many species but is very important from an international perspective, as many of these species depend largely on the Netherlands for their existence (Reemer et al. 2009). Dutch policy on nature conservation Adenosine should therefore concentrate more of its efforts on this

area. This example highlights the need for an evaluation at a higher (Europe-wide) level to assess the importance of different species and regions. Acknowledgements We are grateful to Nienke van Geel for digitizing the climate maps and to Jolijn Radix, Marja Seegers, and Anouk Cormont for constructing the map of Dutch landscape age. We thank Peter de Ruiter, Nancy Smyth and two anonymous reviewers for their comments on the manuscript. Open Access This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. Appendix 1 See Table 5. Table 5 Mean values (±SD) of the 33 possible discriminatory environmental variables used in the stepwise discriminant analysis for the different biogeographical regions with characteristic species Variables DUNE (n = 64) FEN (n = 115) SAND (n = 221) SE (n = 226) LIMB (n = 26) Elevation (m) 1.7 ± 3.4 0.5 ± 3.7 16.6 ± 15.4 16.6 ± 11.6 89.2 ± 51.8 Groundwater table in spring (m below sea level) 0.7 ± 0.3 0.4 ± 0.2 0.9 ± 0.4 0.8 ± 0.2 1.7 ± 0.4 pH 6.2 ± 0.5 6.1 ± 0.5 5 ± 0.5 5.6 ± 0.5 6.3 ± 0.4 Nitrogen deposition (mol/ha per year) 1564.4 ± 636 1960 ± 418 2295.