Details

Autor(en) / Beteiligte

• van Haperen, Anton M. M

Titel

Een Wereld Van Verschil: Landschap En Plantengroei Van De Duinen Op De Zeeuwse En Zuid-Hollandse Eilanden

Ort / Verlag

ProQuest Dissertations & Theses

Erscheinungsjahr

2009

Link zum Volltext

• ProQuest

Quelle

ProQuest Dissertations & Theses A&I

Beschreibungen/Notizen

• Landscape and vegetation of the dunes on the islands of the South-West Netherlands not only differ from each other; compared with the Holland and Flemish mainland coast they have a peculiar character as well. Although established long ago, these features have never been properly described and explained. Therefore this book covers the vegetation of the dunes on Voorne, Goeree, Schouwen and Walcheren, the abiotic differences among these dune areas and the role of man in it.Geobotanical explorationFloristic similarities and differences at the island level (chapter 4): The number of Red List species found in the dunes of the different islands since the mid-19th century is largest in Voorne (130). On Walcheren, Schouwen and Goeree this number ranges from 87 to 95. Dune areas with comparable species diversity do not always include the same species. In all dune areas half of the Red List species found there are pioneer and grassland species. The islands differ distinctly in the number of Red List species that has disappeared over the years. More species have disappeared from the Walcheren dunes than from the other islands (43% and 28-30% respectively). Also, clear differences can be seen in particular species groups. Hygrophytic species declined most strongly on Walcheren. Species of dry and eutrophic grasslands declined especially on Voorne, Walcheren and Schouwen. Dune grassland plants maintained themselves remarkably well on Goeree. The same holds for thicket and forest plants on Voorne.Dune slack vegetation (chapter 6): Wet and humid dune slacks contribute significantly to the botanical diversity of dunes in the South-West Netherlands. Especially the pioneer stages are rich in rare and endangered species. Within the plant communities of the wet and humid dune slacks three groups can be distinguished, whereby hydrological regime and chemical buffering are the main determining factors. The communities of calcareous soils that are under the influence of groundwater (basophilic mesoseries: CentaurioSaginetum and Junco baltici-Schoenetum nigricantis) have the largest species diversity and accommodate the largest number of Red List species.Within the Junco-Schoenetum a clear differentiation between communities of the calcareous coastal dunes and those of the exposed soils of the former tidal flats in the enclosed estuaries is manifest in the South-West Netherlands. The Junco-Schoenetum of the slacks in the calcareous coastal dunes has the highest species diversity. Differences in species diversity and species composition are connected with differences in environmental conditions. In the coastal dunes inflowing basic groundwater plays a larger role. Here, it leads to more humid conditions and the calcium-rich and bicarbonic groundwater creates better conditions for buffering in the developing humus layer as well. Hence, species preferring moist and neutral humus find better environmental conditions here.The dune areas themselves also differ markedly from each other with respect to plant community occurrence. On Voorne, plant communities of dune slacks are most rich in species. This goes for both the slacks that inundate for a longer period in the wet season (hygroseries) as well as calcium-rich slacks primarily influenced by inflowing groundwater (basophilic mesoseries). Both slack types are presently hardly developed on Walcheren, but likely were more common here in previous years. Calcium-poor slacks influenced by groundwater (acidophylic series) do not occur on Voorne. Those mainly occur on Goeree (inland dunes only), Schouwen (inland and coastal dunes) and Walcheren (inland and coastal dunes).Humid mesotrophic grassland (chapter 7): Various types of humid mesotrophic grassland can be found in and along the dune coast of the South-West Netherlands, with a large number of remarkable species. These mesotrophic grasslands occupy different landscape ecological positions and differ from each other depending on the way in which the acidity in the top soil layers is buffered. (Abstract shortened by ProQuest).