Salt marshes in the Netherlands Wadden Sea: rising high-tide levels and accretion enhancement
Dijkema, K.S.; Bossinade, J.H.; Bouwsema, P.; De Glopper, R.J. (1990). Salt marshes in the Netherlands Wadden Sea: rising high-tide levels and accretion enhancement, in: Beukema, J.J. et al. (Ed.) Expected effects of climatic change on marine coastal ecosystems. Developments in Hydrobiology, 57: pp. 173-188
In: Beukema, J.J.; Wolff, W.J.; Brouns, J.J.W.M. (Ed.) (1990). Expected effects of climatic change on marine coastal ecosystems. Developments in Hydrobiology, 57. Kluwer Academic Publishers: Dordrecht/Boston/London. ISBN 978-94-010-7397-4; e-ISBN 978-94-009-2003-3. 221 pp. https://dx.doi.org/10.1007/978-94-009-2003-3, more
In: Dumont, H.J. (Ed.) Developments in Hydrobiology. Kluwer Academic/Springer: The Hague; London; Boston; Dordrecht. ISSN 0167-8418, more
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| Authors | | Top |
- Dijkema, K.S., more
- Bossinade, J.H.
- Bouwsema, P.
- De Glopper, R.J.
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| Abstract |
Sea-level rise will become a worldwide threat to coastal marshes by affecting the marsh vegetation through an increased number of tidal floodings and an increase in wave energy. The survival of salt marshes depends on the accretionary balances in both the marsh zone itself and the pioneer zone in front of the marsh. The pioneer zone, which is transitional to the tidal flats, is situated on a level which is most affected by wave action. Moreover, it lacks the protection of a closed vegetation cover. In the Netherlands Wadden Sea more than half of the foreland salt marshes (which are man-made) showed an accretional deficit in this pioneer zone during a period with rising high-tide levels. This will lead to cliff formation and marsh erosion from the seaward edge. Sea-edge erosion has been observed for most of the barrier-island salt marshes in the Wadden Sea. In the salt-marsh zone itself mostly a positive accretionary balance occurs due to the effect of the vegetation cover on sedimentation and erosion protection. The vertical accretion rate of the man-made foreland marshes is high enough to compensate for a future sea-level rise of 1 to 2 cm per y. The outlook for the barrier-island salt marshes is bad if the sea-level rise will increase to values of 0.5 to 1.0 cm per y, which might be expected for the next century. The response of marsh vegetation and sedimentation to year-to-year changes in mean high-tide levels complicates the effects of a long-term sea-level rise and needs more study. A general conclusion is that management techniques to prevent negative effects of sea-level rise have to direct most attention to the pioneer zone where marsh growth starts. Further field studies on the processes of sedimentation and plant establishment in both man-made and natural pioneer zones may provide a base for future management. |
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