PROJECT DESCRIPTION
BACKGROUND
Dune complexes in Natura 2000 network sites in the southwest of the Netherlands comprise calcareous and decalcified dry dunes, older dune slacks, salt marshes, beach plains and new dunes. It is the only coastal area of the Netherlands where natural processes are still active on a large scale. The Dutch dunes form an almost continuous broad area along the coast and contain many habitats listed in the Habitats Directive, including grey dunes (a priority habitat), white dunes, humid dune slacks, dune forest, and salt marches. Humid dune slacks are of great importance for many rare plant species, such as fen orchid (Liparis loeselii). However, dune habitats are threatened, primarily as a result of reduced dune dynamics and, as a consequence, the increased speed of succession. The planting of forests and a decline in rabbit numbers are the most important factors in explaining this rapid succession. The expansion of exotic shrubs and trees such as black cherry (Prunus serotina) and white poplar (Populus alba) is another, more recent factor.
OBJECTIVES
The main aim of the Dutch dune revival project was to enlarge and restore dune habitats and increase the presence of rare and characteristic species in three well-known Dutch dune complexes in the Natura 2000 network in the southwest of the country: Voornes Duin, Duinen Goeree & Kwade Hoek and Kennemerland-Zuid. The project aimed to set back succession to an earlier stage to create good conditions for the development of species-rich grey dunes and white dunes, as well as humid dune slacks, by removing scrub, forest, and grassy vegetation. In areas with narrow-mouthed whorl snail (Vertigo angustior), activities were planned so that populations of this species were not endangered. Depending on the speed of succession after removal of the vegetation, the areas will be mown and/or grazed to secure permanent recovery of the relevant habitats. In Kennemerland-Zuid, the aim was to remove sand at five locations near to the sea to obtain active blowing dunes, which create good conditions for the development of new humid dune slacks.
RESULTS
The Dutch dune revival project conducted habitat restoration on nearly 190 ha of white dune, grey dune and dune slack habitats. The restoration measures included an innovative concept for re-allowing wind dynamics at one of the sites, which could lead to a new best practice for dune restoration. The project treated invasive non-native species on 2 190 ha, and prepared for recurrent management through capacity building activities. A key project success was the innovative restoration of the wind dynamics at Zuid-Kennemerland. Wind-mediated sand drift is considered a crucial element for conserving white dune and dune slack habitats. The restoration of these habitats at Zuid-Kennemerland provides a good demonstration of a large-scale restoration, involving the removal of sand to create five large openings (blow holes) in the first row of dunes, to re-allow natural wind dynamics and therefore wind-mediated sand drift. The profiles of the openings were digitalised using a laser so that the exact desired profile could be dug. For an optimal effect, large areas of vegetation were removed, so the remaining parabola dunes were no longer fixed by plant roots and so could become mobilised. Before digging on the dunes, a specialist company had to clear old ammunition (dating from WWW II).
The effect was closely monitored by associated beneficiary PWN (Waterleidingbedrijf Noord-Holland), who confirmed that wind dynamics are taking effect and sand has started drifting. A working group was set up to evaluate the best recurrent management method, as it is not possible to remove all plant root systems and re-sprouting occurs. This new concept, involving the restoration of wind dynamics, could become the new best practice for dune restoration. It is serving as an inspiration to international nature managers and as an example for the Atlantic biogeographical region. Because of this activity, the project won a Best Practice trophy at the Atlantic Biogeographical Seminar in 2016; it was also nominated for a Natura 2000 award in 2014.
Restoration activities were also completed in the southern areas of the Dutch dune complex, at Voornes Duin and Duinen Goeree & Kwade Hoek. Here, grey dune and dune slack were restored by sod cutting and mechanical scrub removal, to tackle the main issues of succession to scrub vegetation and excessive nitrogen deposition. Fencing was also erected and a year-round grazing programme was started with Highland cattle.
The project removed three invasive non-native species: Prunus serotina, Cotoneaster and Mahonia from dune habitats. Experiments were conducted to evaluate the best approach to their control, though for Prunus serotina no real 'solution' was found. Nevertheless, the project succeeded in removing all seed trees and performed several rounds of aftercare. The key to the long-term success of this activity over the coming years, as set out in the After LIFE plan, will be to make sure that new seedlings do not grow into seed trees. The project put in place the capacity to prevent this happening, through the provision of equipment, the establishment of an expert group and by putting in place a network of volunteers to conduct scrub clearance and seedling removal.
The project directly implements the EU Habitats and Birds Directives, and the EU Biodiversity Strategy to 2020. The project beneficiaries actively participated in the Natura 2000 Biogeographical Process in the Atlantic Region.
Further information on the project can be found in the project's layman report and After-LIFE Conservation Plan (see "Read more" section).
An ex-post visit was carried out by the external monitoring team in 2018, 1.3 years after the project’s completion. This confirmed that a total of 199.58 ha of dune habitat types had been successfully restored, five openings had been created in the first dune row in Kennemerland-Zuid, and that invasive non-native species had been removed from 740 ha of dune habitats, so easing the burden of future control and management. In Kennemerland-Zuid, the numbers of 15 typical dune plant species, selected as indicator species by the project, doubled between 2015 and 2017, including eight reappearances. At Voorne and Goeree, Red Listed plant species increased steeply between 2009 and 2015, and positive developments for typical breeding birds also occurred. The project partners and stakeholders were considered to have cooperated very efficiently to achieve these results. The ex-post visit confirmed that natural dune processes and dynamics had returned, especially in Kennemerland-Zuid. The openings in the first dune row resulted in wind patterns that drive mobile dunes, which are gradually 'walking' over the area. Without further human interference, these processes will continue and dune dynamics will be close to natural. This supports many pioneer species that are typical for these habitats, but are endangered in the Netherlands. The project created corridors between white and grey dunes, to increases resilience of these habitats and their species. Succession will now allow vegetation patches to move around, such that all the target habitats, together with their typical species, will profit in the long-term.
The restored dune zone will act as a more effective barrier to possible sea level rise or floods coming from high seas, which are likely to be exacerbated by climate change. The area is also a source for drinking water, making flood control especially important. In terms of long-term funding, the national fund Programmatic Approach Nitrogen will fund the necessary management actions in the north, and it is being explored for the south. Budgets from within the beneficiaries will be mobilised to manage the sites as part of their mandates.
