Roadmap voor herstel Weerribben-Wieden: Effecten laag-dynamisch water- en natuurbeheer

Nationaal park Weerribben-Wieden - een biodiversiteishotspot - is qua omvang en ecologische kwaliteit het belangrijkste laagveengebied in Nederland. Verschillende habitattypen uit de verlandingsreeks (zie Kooijman et al. dit nummer) staan echter ook hier (sterk) onder druk door te hoge nutrientenaanvoer, onvoldoende basenaanvoer, atmosferische stikstofdepositie en afnemende openheid. Dit artikel gaat dieper in op deze problemen en de effectiviteit van de verschillende beheers- en inrichtingsmaatregelen die zijn toegepast in het park. - National Park Weerribben-Wieden is a hotspot of biodiversity in which the ecological quality has improved over the past 20 to 30 years. However, several habitat types are still under pressure as a result of high nutrient supplies, insufficient base supply, atmospheric nitrogen-deposition and afforestation. Due to these factors, the park suffers from two main problems: slow development of young terrestrializing vegetations and accelerated succession of older stages such as rich and poor fens. Although the current management of these older stages (consisting of sod-cutting, deforestation, summer-mowing and digging gullies) seems quite successful in Weerribben-Wieden, this management is inadequate to guarantee the area and quality of rich and poor fens in the long run. In addition, new formation of young terrestrializing vegetations is essential to guarantee a diversity of different successional stages in future. Although terrestrialization is starting up again, it will take decades to develop new rich fens. For this reason, active ecohydrological management is highly desirable to improve water quality by increasing the base supply and reducing nutrient supply. In the meantime, it is very important to maintain, or even expand, the current well-developed populations of rich and poor fens