Coastal Management Assessment commissioned by the Agency for Maritime and Coastal Services
In the period 2021-2023, INBO conducted a monitoring of the flora and vegetation of twelve dune areas, totaling 338 ha. This was commissioned by the manager of those areas, the Agency for Maritime and Coastal Services of the Flemish government.
The vegetation of the study area includes a large part of the marram grass dunes on our coast, as well as the associated, very characteristic foredune species. The foredune is the high first ridge of dunes on the seaward side. The marram dunes undergo little shifting and are therefore generally not in a favourable state of preservation. Upright scrub and forest occupy about half of the area of the dunes surveyed. The forests are mainly abel plantations with limited ecological value.
On the basis of repeated mapping we infer a net expansion of the special species, both in population size and species number. A clear increase is seen among species of the foredune, of moss dune and dune grassland, and among dune valley species. An important cause of this is probably climate warming, but nature conservation and management also clearly have a positive effect. We observe a decrease especially in high beach species and a number of sensitive, often more moisture-loving grassland species. For the latter, grazing, overgrowth and possibly desiccation are a problem.
Furthermore, we mapped about 70 non-native, often invasive plant species. Especially woody non-native species such as rugosa rose, oleaster species, Ligustrum ovalifolium, Tamarix gallica and Lycium are a problem and overgrow native vegetation. The European project LIFE DUNIAS is committed to controlling them, which has reduced their area in the meantime.
Controlling alien invasive plant species is therefore an important focus of management recommendations. Furthermore, we advocate the expansion of dune grassland, the priority European protected habitat type 2130. In the marram grass dunes, management should lead to greater dynamics, something to which the removal of alien invasive species can certainly contribute. Finally, we propose to take measures to reduce disturbance on the beaches. This includes both rest disturbance and overcrowding by recreation, as well as more large-scale disturbance through regular re-profiling of bathing beaches.
Image above: Sam Provoost