Cosyns, E.

Zwaenepoel, A.

Open Marine Archive

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area in Flanders and makes the river basin 5 times more secure against floods. The project area is a part of 
the Natura2000 network 
LIFE+ Scalluvia (2013-2017) will substantially and permanently improve the state of conservation of 80 ha 
of alluvial forests with Alnus glutinosa and Fraxinus excelsior (Alno padion, Alnion incanae, Salicion albae) and 10 
ha of creeks (natural eutrophic lakes with Magnopotamion or Hydrocharition).
To improve the water quality and quantity for the forests and creeks, the wastewater from the town has 
been deviated for water treatment and adjustable dams will make the water level of the alluvial forests 
controllable  The construction of a special five level fish passable flood control dam will let fish migrate 
from and to the river Scheldt  The banks of the creeks will be reconstructed in an ecological manner and 
burrowing fish species will be removed. The forest itself will be cleared from invasive or exotic species and 
from former ponds and lodges  To improve the structure and the amount of dead wood, some big remaining 
poplars will be ring-barked and scrubs will be planted  
The habitat restoration will benefit the re-establishment of European bitterling, spined loach, blue throat, 
common kingfisher, little bittern, and purple heron. The Scalluvia area will acquire the protection status of 
Flemish nature and forest reserve 
The benefits of the Polders van Kruibeke to society are enormous  Flood control is the most important 
service. To build the flood control area, more than 600 ha have been expropriated and closed for public for 
more than 10 years  In 2014 the area was partly reopened for the public 
Recreation is since another important service to society and leads to acceptance  With Scalluvia, we invite 
people to (re)discover the area. After consulting the stakeholders, infrastructure for hikers, bikers and 
fishermen was built. Collective maintenance actions to experience nature, a smart phone game for animated 
walks, a play forest, field classes, training of guides, and guided walks constitute special topics.
To inform people about the area, time capsules are built  A time capsule is a place within the area where 
visitors can rest and receive information on the past, present or future of that place  Ample information is 
available through social and written media 
Furthermore, we experience with site-specific art, as nature often inspires and art can be the perfect 
way to invite people to visit and discover nature  We actually test the developed vision on the relationship 
between art and nature with two site-specific art works.
However, none of these measures may jeopardize the challenging nature goals or the functioning of the flood 
control area  In every action we continuously balance nature goals, flood control and the demand for 
recreation.
www scalluvia eu 
WORKSHOP 
Vegetation succession in the Zwin estuary 2010-2014. Effects of natural processes and nature 
management 
Eric Cosyns,  Arnout Zwaenepoel 
West-Vlaamse Intercommunale, BRUGGE, Belgium
Introduction
Since 1987 we observe a progressive silt accretion of the mud flats and salt marshes of the Zwin. This 
situation led to a dramatic decrease in area occupied, amongst others, by the habitat type 1310 - Salicornia 
and other annuals colonizing mud and sand, and habitat type 1330 Atlantic salt meadows  Meanwhile, a 
Halimione portulacoides salt marsh community became dominant in the lower areas, whereas Elymus athericus 
did in more elevated areas  That resulted in a dramatic loss of plant and bird biodiversity  
The Flemish regional nature and forest agency aims at restoring this rich biodiversity by carrying out the 
large-scale LIFE program ZTAR - Zwin Tidal Area Restoration This program includes amongst others:
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ral presentation abstracts in alphabetical order 
• Sod cutting and removal of the dominant Elymus athericus in an 8 ha area (removing the upper 20 cm of 
soil) in order to rejuvenate the salt marsh.
• Re-introduction of cattle, i e  cows and sheep, for seasonal low density grazing of the salt marsh  
However, there are many setbacks and problems associated with salt marsh restoration that require careful 
long-term monitoring  Information on all components of the salt marsh ecosystem should be understood 
and monitored, from sedimentation and tidal influences, to behaviour patterns and tolerances of both flora 
and fauna species  A better understanding of processes and patterns can help to suggest more sound and 
practical nature management and restoration efforts for this area  Therefore one of the interventions was 
to set up a vegetation survey 
Material and methods
In 2010 we started monitoring the vegetation succession along 14 transects with a total length of 332 m  We 
continuously sampled vegetation along these transects using 2 x 2 m relevs  Monitoring was carried out at 
T0 = sept  2010, sept  2013 & sept  2014  Transects were set up under different management regimes: low-
density cattle grazing (100 m, 4 transects), sheep grazing (38 m, 2 transects), sod cutting (62 m 2 transects), 
no management or under natural succession (132 m, 6 transects).
Results & discussion
Under natural conditions we observed a rapid and strong decline of pioneer habitat (Eu-1310) in favour of 
Glauco-Puccinellietalia maritimae communities in the lower salt marsh  However also the latter showed a net 
loss of cover  Overall Elymus athericus became more dominant in the salt marsh  This may be the result of a 
still ongoing silt accretion and the corresponding increase of nitrogen in the topsoil 
Extensive, seasonal grazing is able to slow down this natural succession, thereby maintaining a higher plant 
diversity  Trampling creates small gaps that favour pioneer species whereas grazing alters light concurrence and 
litter accumulation  Sod cutting and topsoil removal is a drastic measure pushing back vegetation succession 
to the initial pioneer state  As diasporas of target species are well available we expect the development of 
the desired EU-habitats to be realistic 
CONTRIBUTED LECTURE 
Realization of a cross-border Natura 2000 European protected area and the Dutch ‘Nature 
Protection Act’
Ir E. Hoogendam and mr E.E.M.J. Haverkorn van Rijsewijk
The extension of the Zwin reserve with 120 hectares, 10 of them being Dutch territory, is laid down 
in the ‘Treaty Scheldt Estuary Development Outline 2010’ between the Flemish Region and the State of the 
Netherlands  As part of the preparation one cross-border Environmental Impact Report with an appropriate 
assessment has been drawn up  The border between Flanders and the Netherlands runs right through the 
Zwin 
As a result of the work on the Zwin creek, during a first period after the construction, changes willtake place 
in the mosaic of habitat types (H1310A, H1320, H1330A, H1330B). For some habitat types, this will lead  to 
a temporary areal loss  During the next phase those habitats willreturn, although nature does not bother 
about the Flemish-Dutch border  Looking at the Zwin nature reserve as a whole, within a period of ten years 
the habitat types concerned will have increased with a surface larger than the initial loss in the Netherlands  
As a matter of fact, in connection with the extension, 120 hectares of nature reserve will have been added  
However, considering the picture from both national perspectives, as the legislation demands, gives rise to a 
complicated situation 
The workshop will take a closer look at the differences between the ecological line of approach and the 
legal point of view 


Vegetation succession in the Zwin estuary 2010-2014. Effects of natural processes and naturemanagement

http://www.vliz.be/imisdocs/publications/317480.pdf

Vegetation succession in the Zwin estuary 2010-2014. Effects of natural processes and naturemanagement

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