Biological and abiotic factors influencing the settlement and survival of Salicornia dolichostachya in the intertidal pioneer zone
Tóm tắt
During the last two decades a decrease of salt marsh area of at least 6% was found along the mainland coast of the Dutch Wadden Sea. However, it was not clear what determined the seaward boundary of the pioneer vegetation in this area. In the period 1993–1995, abiotic and biological variables were monitored along a transect from the mudflat to the low salt marsh in two sites, the Negenboerenpolder and the Noordpolder. At the Negenboerenpolder site the pioneer zone extended further from the dike and had a dense cover with vegetation when compared to the Noordpolder site. The observed difference in extension of the pioneer zone could not be attributed to differences in tidal frequency, sedimentation rate or nutrient availability. During the winter a dramatic loss in seed numbers was found at both sites. This loss decreased from mudflat to low marsh. The mud/sand ratio, on the other hand, increased from mudflat to low marsh and was higher in the Negenboerenpolder. The shear strength of the top soil layer measured with an in‐situ erosion flume was correlated to the mud/sand ratio and increased with an increasing mud content of the soil. The strength of the soil seems to be the key factor for the settlement and survival of Salicornia dolichostachya in the pioneer zone.
Tài liệu tham khảo
Armstrong, W., Wright, E.J., Lythe, S and Gaynard, T.J. 1985. Plant zonation and the effects of the spring-neap tidal cycle on soil aeration in a Humber salt marsh. Journal of Ecology 73: 323–339.
Beeftink, W.G. 1985. Population dynamics of annual Salicornia species in the tidal salt marshes of the Oosterschelde. Vegetatio 61: 127–136.
Boumans, R.M.J. and Day Jr., J.W. 1993. High precision measurements of sediment elevation in shallow coastal areas using a sedimentation-erosion table. Estuaries 16: 375–380.
Caldwell, M.M., Richards, J.H., Manwaring, J.H. and Eissenstat, D.M. 1987. Rapid shifts in phosphate acquisition show direct competition between neighbouring plants. Nature 327: 615–616.
De Glopper, R.J. 1986. Rijkslandaanwinningswerken; werkwijze en enkele onderzoeksresultaten. pp. 23–32. In: De Glopper, R.J. (ed.), Wadden en Landaanwinning. Flevobericht 252. Rijksdienst voor de IJsselmeerpolders, Lelystad, The Netherlands.
De Leeuw, J., Apon, L.P., Herman, P.M.J., De Munck, W. and Beeftink, W.G. 1992. Vegetation response to experimental and natural disturbance in two salt-marsh plant communities in the Southwest Netherlands. Netherlands Journal of Sea Research 30: 279–288.
Dijkema, K.S. 1997. Impact prognosis for salt marshes from subsidence by gas extraction in the Wadden Sea. Journal of Coastal Research 13: 1294–1304.
Dijkema, K.S., Bossinade, J.H., Bouwsema, P. and De Glopper, R.J. 1990. Salt marshes in the Netherlands Wadden Sea: rising high tide levels and accretion enhancement. pp. 173–188. In: Beukema, J.J., Wolff, W.J. and Brouns, J.K.W.M. (eds), Developments in Hydrobiology, Expected effects of Climatic Change on Marine Coastal Ecosystems. Kluwer Academic Publishers Dordrecht, The Netherlands.
Groenendijk, A.M. 1986. Establishment of a Spartina anglica population on a tidal mudflat: a field experiment. Journal of Environmental Management 22: 1–12.
Houwing, E.J. and Van Rijn, L.C. 1998. In-situ erosion flume (ISEF); determination of bed shear stress and erosion of a kaolinite bed. Journal of Sea Research 39: 243–253.
Howes, B.L., Dacey, J.W.H. and Goehringer, D.D. 1986. Factors controlling the growth form of Spartina alterniflora: Feedbacks between above-ground production, sediment oxidation, nitrogen and salinity. Journal of Ecology 74: 881–898.
Huiskes, A.H.L., Stienstra, A.W., Koutstaal, B.P., Markusse, M.M. and Van Soelen, J. 1985. Germination ecology of Salicornia dolichostachya and Salicornia brachystachya. Acta Botanica Neerlandica 34: 369–380.
Jefferies, R.L., Davy, A.J. and Rudmik, T. 1981. Population biology of the salt marsh annual Salicornia europaea agg. Journal of Ecology 69: 17–31.
Kamps, L.F. 1962. Mud distribution and land reclamation in the eastern Wadden shallows. Rijkswaterstaat Communications 4: 1–73.
Londo, G. 1975. De decimale schaal voor vegetatiekundige opname van permanente kwadraten. Gorteria 7: 101–106.
Mitchener, H. and Torfs, H. 1997. Erosion of mud/sand mixtures. Coastal Engineering 29: 1–25.
Smit-Van der Waaij, Y., Houwing, E.J., Van Duin, W.E. Dijkema, K.S. and Smit, J.P.C. 1995. Salt marshes and sea-level rise: Boundary conditions for the growth of Salicornia dolichostachya. Institute for Marine and Atmospheric Research (IMAU), Utrecht University, IMAU-report R95–26, The Netherlands.
Snow, A.A. and Vince, S.W. 1984. Plant zonation in an Alaskan salt marsh. II. An experimental study of the role of edaphic conditions. Journal of Ecology 72: 669–684.
Tyler, G. 1967. On the effect of phosphorus and nitrogen, supplied to Baltic shore-meadow vegetation. Botanical Notiser 120: 433–447.
Van Eerdt, M.M. 1985. The influence of vegetation on erosion and accretion in salt marshes of the Oosterschelde, The Netherlands. Vegetatio 62: 367–373.
Wiehe, P.O. 1935. A quantitative study of the influence of the tide upon populations of Salicornia europaea. Journal of Ecology 23: 323–333.