Kieshofer
Moor and
Karrendorfer Wiesen: Mire
and salt grassland restoration
"Kieshofer
Moor" and
"Karrendorfer
Wiesen" are two excamples of successful
restoration projects in the immediate vicinity
of Greifswald. Both sites were subject to numerous
studies and long time observations.
The
“Kieshofer Moor” was
originally an open, oligo-mesotrophic and acidic
mire with typical species of bog vegetation. Drainage in the
early 19th
century led to the establishment of forests on the mire and the
decrease of mire
vegetation. Revitalisation started in 1980
with the removal of trees on about 5 ha in the centre of the mire
inducing a
rapid, but only short-term spread of Sphaghnum, Eriophorum
and other mire species.
Due to
still too low water level trees could re-establish, requiring permanent
maintenance of the site.A first dam built in 1988
hardly improved the
situation. Only a new and more solid dam built
in 1993 led to permanent
rewetting of the mire. In
1994 90 % of the mire was flooded.
Floating mats of Lemna
established between dead trees, giving a
disastrous picture. But since then, a mire vegetation with e.g. Sphagnum
fallax, S. fimbriatum, S. palustre, Eriophorum vaginatum
and E. angustifolium
expanded. Today, large parts of mire again accumulate peat.
The
„Karrendorfer Wiesen“ are
situated at the shore of the Greifswalder
Bodden, a bay of the Baltic Sea. The site is characterised by
about 1
m of peat in the underground. Surprisingly peat formation in the past
took place high above the mean water level of the Baltic Sea. The
main reason is compaction of the biomass due to grazing cattle.
In
combination with episodic flooding, decomposition of plant material is
strongly reduced. The slow increase of the sea level due to isostatic
movements of the area further stimulated this process. Such mires
are
described as coastal transgression mires, the peat as salt meadow
peat. Intensive
diking stopped flooding of the
Karrendorfer Wiesen in the
early 1970s. This allowed intensified farming, but boosted
decomposition of peat and thus lowered the surface of the
area.
Today
parts are below mean sea water level. In the early 1990s authorities
therefore stimulated the removal of the
dikes. About 360 ha are now again influenced by flooding, in total the
Karrendorfer Wiesen include 700 ha of salt meadows.
Due to
still too low water level trees could re-establish, requiring permanent
maintenance of the site.A first dam built in 1988
hardly improved the
situation. Only a new and more solid dam built
in 1993 led to permanent
rewetting of the mire. In
1994 90 % of the mire was flooded.
Floating mats of 
The
„Karrendorfer Wiesen“ are
situated at the shore of the Greifswalder
Bodden, a bay of the Baltic Sea. The site is characterised by
about 1
m of peat in the underground. Surprisingly peat formation in the past
took place high above the mean water level of the Baltic Sea. The
main reason is compaction of the biomass due to grazing cattle. 
In
combination with episodic flooding, decomposition of plant material is
strongly reduced. The slow increase of the sea level due to isostatic
movements of the area further stimulated this process. Such mires
are
described as coastal transgression mires, the peat as salt meadow
peat. Intensive
diking stopped flooding of the
Karrendorfer Wiesen in the
early 1970s. This allowed intensified farming, but boosted
decomposition of peat and thus lowered the surface of the
area.
Today
parts are below mean sea water level. In the early 1990s authorities
therefore stimulated the removal of the
dikes. About 360 ha are now again influenced by flooding, in total the
Karrendorfer Wiesen include 700 ha of salt meadows.
