Wetlands of recent Dutch embankments

Abstract

Wetlands of new embankments are characterized with respect to soil and hydrological regime and the processes of desalination and vegetation succession. Soil-and height gradients, the lack of local drainage and the generally low nutrient content provide conditions for dynamic mesoseries (groundwatertable low in summer, saturated in winter) and locally for stable mesosen·es (relatively high in summer, saturated in winter).Relations between vegetation and herbivores (geese, ducks, cattle) are discussed.

Remote locality of the littoral Carex extensa (Cyperaceae) in Hungary — long distance dispersal from coastal to inland salt marshes

“…The outer part ('embankment area') has been transformed dramatically as a consequence of declining ground water level and salt accumulation in the upper horizons of the soil. The effects of these changes were similar of those of the embankments in the Netherlands (Beeftink 1975;Joenje & Verhoeven 1993) and in other Hungarian plain landscapes (Molnár & Borhidi 2003); the transformation of habitats rich in Schoenus nigricans at Lake Fertő was described and analysed by Lájer (2006). In the course of secondary succession, the vegetation became closer to that of salt marsh and meadow communities, with pioneer swards on the open soil surfaces (Fig.…”

Long-Term Effects of Tidal Exclusion on Salt Marsh Plain Species at Estero de Punta Banda, Baja California

“…In contrast with the salination process that results from tidal restriction in arid estuaries (e.g., Alexander and Dunton 2002;Zedler and West 2008;Ritter et al 2008;this study), in humid climate estuaries embankment generally results in a desalination process, as wetlands receive fresh water input mainly from precipitation and drainage (Joenje 1974;Joenje and Verhoeven 1993). In quickly desalinating areas, a rapid increase of biomass and the appearance of many species have been reported.…”

“…In quickly desalinating areas, a rapid increase of biomass and the appearance of many species have been reported. For example, in the Lauwerszee-polder, The Netherlands, in a single year the number of species increased from 30 to over 150 (Joenje 1974); clay sediments become better aerated, and percolating precipitation water washes the salt downwards allowing the development of vegetation (Joenje and Verhoeven 1993).…”

“…These structures facilitate the drainage and canalization of wetlands, to increase the area for industrial activities, agriculture and forestry (Kennish 2001;Hansson et al 2005). Water control structures in coastal marshes can reduce (Beeftink 1975;Alexander and Dunton 2002) or increase freshwater input into salt marshes (Adams and Bate 1994;Davis and Froend 1999;Álvarez-Rogel et al 2007), alter water levels (Beeftink 1987), or restrict tidal inundation (Joenje 1974;van Noordwijk-Puijk et al 1979;Joenje and Verhoeven 1993;Leeuw de et al 1994;Ritter et al 2008). The resulting hydrologic changes not only have an immediate compositional impact on wetland vegetation but also affect ecosystem-level processes, such as primary production and biomass accumulation (Roman et al 1984; Barrett and Niering 1993;St.…”