influence on the area of open pioneer vegetation. Thus, grazing can be an efficient
tool for increasing biodiversity in grass-encroached dune areas, but the youngest
and oldest stages of the dune landscape have the best opportunities.
15.3.2 Rewetting and Sod Cutting in Dune Slacks
Three cases will be discussed with respect to dune slack restoration, where sod
cutting and rewetting was carried out and where the results have been monitored
for 12–18 years. Two examples are from the Dutch Wadden Sea islands (Koegelwieck, Terschelling and the Moksloot area, Texel) and one example from the
Holland coast.
In the Koegelwieck valley on the island of Terschelling sod-cutting experiments have been present since 1954 and various stages of vegetation development
are present in a chronosequence.
In the Moksloot area a groundwater abstraction facility has been terminated in
1993 and large scale sod-cutting has been applied to restore typical dune slack
vegetation (Grootjans et al. 2001).
In the Holland dune area (Meinderswaal valley) sod cutting has been applied
after the introduction of new groundwater abstraction techniques (see Box 15.1),
which led to a considerable rewetting and restoration of the hydrological system.
15.3.2.1 Koegelwieck, Island of Terschelling
The dune slack in the Koegelwieck area is about 100 years old. It is a large
secondary dune slack on the island of Terschelling, which was formed because of
massive sand blowing in the early twentieth century and became vegetated around
1910. It is mainly fed by precipitation water, except during winter and early spring,
when calcareous groundwater enters the slack from an inland dune massive
Table 15.2 Effects of grazing in various parts of Dutch dune areas
Dune zone
Organic matter
pH
Open pioneer vegetation (%)
a
Grazed
Not grazed
H foredunes
Low
7.4 (0.3)
80
45
H middle dunes
Intermediate
5.0 (0.5)
13
9
H hinter dunes
High
4.1 (0.1)
75
55
Wadden islands
High
4.2 (0.3)
60
13
a Data on the effect of grazing were obtained from vegetation surveys between 2001 and 2008
(Holland coast) and between 1992 and 2008 (Wadden Sea islands)
244
A. P. Grootjans et al.
tool for increasing biodiversity in grass-encroached dune areas, but the youngest
and oldest stages of the dune landscape have the best opportunities.
15.3.2 Rewetting and Sod Cutting in Dune Slacks
Three cases will be discussed with respect to dune slack restoration, where sod
cutting and rewetting was carried out and where the results have been monitored
for 12–18 years. Two examples are from the Dutch Wadden Sea islands (Koegelwieck, Terschelling and the Moksloot area, Texel) and one example from the
Holland coast.
In the Koegelwieck valley on the island of Terschelling sod-cutting experiments have been present since 1954 and various stages of vegetation development
are present in a chronosequence.
In the Moksloot area a groundwater abstraction facility has been terminated in
1993 and large scale sod-cutting has been applied to restore typical dune slack
vegetation (Grootjans et al. 2001).
In the Holland dune area (Meinderswaal valley) sod cutting has been applied
after the introduction of new groundwater abstraction techniques (see Box 15.1),
which led to a considerable rewetting and restoration of the hydrological system.
15.3.2.1 Koegelwieck, Island of Terschelling
The dune slack in the Koegelwieck area is about 100 years old. It is a large
secondary dune slack on the island of Terschelling, which was formed because of
massive sand blowing in the early twentieth century and became vegetated around
1910. It is mainly fed by precipitation water, except during winter and early spring,
when calcareous groundwater enters the slack from an inland dune massive
Table 15.2 Effects of grazing in various parts of Dutch dune areas
Dune zone
Organic matter
pH
Open pioneer vegetation (%)
a
Grazed
Not grazed
H foredunes
Low
7.4 (0.3)
80
45
H middle dunes
Intermediate
5.0 (0.5)
13
9
H hinter dunes
High
4.1 (0.1)
75
55
Wadden islands
High
4.2 (0.3)
60
13
a Data on the effect of grazing were obtained from vegetation surveys between 2001 and 2008
(Holland coast) and between 1992 and 2008 (Wadden Sea islands)
244
A. P. Grootjans et al.