Plants and algae

The Belgian part of the North Sea (BNS) forms a unique ecosystem with a wide range of plants and algae. Various vegetation zones developed due to the varying influences of salt, sand, wind, currents and tides. These abiotic factors often require various physiological and morphological adjustments from the vegetation present in order to be successful.

The Belgian seabed, due to a lack of light and sandy subsoil, is mainly uncultivated. Artificial hard substrates such as breakwaters and offshore structures, on the other hand, are easier to colonise and often contain an abundance of algae. Only short-lived vascular plants such as European searocket (Cakile maritima) and sea sandwort (Honckenya peploides) can be found on the tide line and on the dry beach. Further inland, near the dune line, there is more variation. For example, the seaward slope often supports a lush vegetation consisting of low shrubs and heather plants. The landward slopes are drier and scarcely covered with drought-resistant plants such as mosses, lichens and grey hair-grass (Corynephorus canescens). The Zwin, the Yser estuary and the Bay of Heist form special vegetation zones along our coast, as these areas are home to mud flats and salt marshes. The vegetation has been adapted to a saline environment by frequent flooding with sea water.

However, coastal vegetation is under pressure from all sides. There is increasing competition from invasive alien plant species (Provoost et al. 2004), but pollution and the trampling of vegetation by various human activities are also a threat. Good management and adequate legislation are therefore very important. For example, the European Habitats Directive designates special protection zones for the protection of fauna and flora.

In the context of good management and policy, the correct inventory and monitoring of vegetation is of great importance. Different methods can be used for this purpose. On a 'small' scale, the choice is often made to determine the abundance of vegetation in a certain area on the basis of, for example, the Braun-Blanquet or Tansley scale. Mapping larger areas is currently done by remote sensing.

Plants and algae