Restoration of mires in
Estonia
Mati Ilomets
Institute of Ecology
Tallinn University
M. Iljin 1952. Conquest of the Nature. Eesti Riiklik
Kirjastus, Tallinn, 142 lk. Translation from Russian
• Endlessly diverse is the nature - in this its
beauty, its power, but in this its hardship for
transformations
• Here we have to know everything, to foresee
everything if people wish to replace the old state
with the new one – with the WISE one
Distribution of peat-covered land in Estonia
0
25
km
50
Estonia 1952
• According to state amelioration scheme
some 1,55 milj ha of land will need
drainage
Estonia 1992
• Some 1.2 mil. ha of peatlands
and paludified areas are drained
– ca 360 000 ha for agriculture
– ca 450 000 ha for forestry
– ca 20 000 ha for peat excavation
– But what has happened with the rest 370
000 ha?
Distribution of main mire types in Estonia in 1950
(after Laasimer, 1965) and in 2012 (after Paal,
Leibak, 2013)
Mire type
1950
% in excell. + very
good state in
2012
2012,
in excell. + very good
state
ha
N
Poor fens
152 000
5
7 800
361
Rich fens
74 900
21
15 600
1 073
Floodplain fens
83 000
3
2 420
109
1 500
45
670
227
76 200
38
29 100
1 290
3 000
36
1 090
77
Open bogs
250 000
50
124 500
1 023
Total
640 600
28
181 180
Spring fens
Mixotrophic fens
Heath moors
Restore or not to restore?
Ca-rich fens
Gradient of specific electricity (μS cm-1) in the pore
water of spring fen
700
Tufa-forming spring fen
Affected by drainage
600
500
400
300
200
100
0
P30
P31
P11
ECMay 09
P4
P38
ECNov 09
P8
P9
ECMay10
P10
Mosses, Paraspõllu site
DCA
Experimental site
Methods
•
•
•
In spring 2009 five experimental blocks by
10 x10 m were established with 6
piesometers per block
water level rise was ca 20-30 cm by
damming shallow ditch (50 cm deep)
Sample quadrates 1x1 m in three rows and
3 cut-down levels – Treatment 1, 2, 3
respectively
•
•
•
Row 3
21
Row 2
14
Row 1
7
1
20
13
6
6
4
2
19
18
12
11
5
4
17
10
3
5
16
15
9
8
2
1
3
1
Four years factorial succession of T1, T2, T3
3
T2-1
T3 -2
Axis 2
Treatment 1 (T1) – tussocks cut
off entirely e.g. from the bottom of
the tussock;
Treatment 2 (T2) – half of
tussock height cut off (leaves, leaf
embryos, litter removed);
Treatment 3 (T3) – standard hay
mowing (leaves, shoots, litter
remowed);
Control 1 & Control 2 (C1 & C2)
– no intervention.
Car dav
Mean bryophyte coverage (%) in 2012 after
four years
Mol caer
T2-1
T3-2
Sch fer
T3-2
T3-3
T3-2
T1-1
T2-2
T3-3
T3-3
Car pan
T2 -2
T1-1
T2-3
T2 -1
T2-3
T3-1
Jun effT1 -3 T1-2 T1 -1
T2-2
-2
Axis
4
T3-1 T2-3
T3-1
T1
T2
T3
C1
C2
Row 1
(qudrate
s 1-7)
9.4
5.0
4.9
0.2
0.7
Row 2
(quadrat
es 8-14)
11.4
8.0
3.1
0.2
1.0
Row 3
(quadrat
es
8.4
8.5
3.5
0.2
0.1
T1-2
T3-1
T1-3
T1-2
T3-3
T1-3
T2-3
T2-2
T2-1
T1-1
T1-2
T1-3
-3
Cover (%) of Molinia caerulea
25
35
20
25
TREAT2
TREAT1
30
15
10
20
15
10
5
5
0
2008
2009
2010 2011
YEAR
2012
0
2008
2013
35
2009
2010 2011
YEAR
2012
2013
2009
2010 2011
YEAR
2012
2013
40
30
30
20
C1
TREAT3
25
15
10
20
10
5
0
2008
2009
2010 2011
YEAR
2012
2013
0
2008
Some results
• Rising up the water level and cut down the
tussocks is most effective intervention to
supress Molinia;
• Half-cutting of tussocks gives advantage to
Carex davalliana and Schoenus ferrugineus to
expand;
• Mowing and litter remowing with simultaneous
rise up of water level may supress Molinia and
favour invasion of Carex panicea and Juncus
effusus.
Revegetation of abandoned peat-fields
In Estonia we have some 8000 ha of peat-fields abandoned
mostly in 1970-ties and 1980-ties
Active revegetation following North-American
approach
Location of study sites
Viru,
2009
Ohtu 18. mai, 2006. a.
Ohtu
2007
ja
2009
S. angustifolium, S. ,magellanicum, S.angustifolium+S.magellanicum, 2009-2012
Ohtu, successional vectors
A1
M1
3
S.rub
Dac glom
Pin syl
Er vag
AM1
Axis 2
1
S.ang
Aul pal
Calam
AM0
A0
M0
S.magell
M2
Pol str
AM2
-1
M3
Cal v Pleur sc
AM3
Ox pal
Bet pub
S.fusc
A2
A3
-3
-3
-1
1
Axis 1
3
S. angustifolium,S. magellanicum and the mixture, successional vectors at two
water level regime 1= 12-30 cm; 2 = 35-50 cm
Ohtu, pure S.angustifolium and mixture with S.magellanicum
9
0
0
2
1
A
︵
︶
4
Dac glom S. rub
︵
︶
0
1
0
2
9
0
0
2
2
A
︵
1
M
A
2
Pin s y l
Axis 2
2
M
A
︵
︶
︶
Pol s tr
Cal v
Calam
Bet pub
Pleur s c
︶ Ox pal
9
0
0
2
1
M
A
︵
Er v ag
A ul pal
1
1
0
2
1
M
A
︵
︶
1
1
0
2
2
A
︶
9
0
0
2
2
M
A
︵
S.ang
0
1
0
2
2
A
︵
0
0
1
0
2
2
M
A
︵
S. magell
︶
S.f us c
︶
︵
︶
1
1
0
2
1
A
︵
0
1
0
2
1
A
-2
︶
-4
-3
-1
1
3
Axis 1
5
Some results
• Success and vectors of revegetation are
highly dependent on hydrology
• Sphagnum diaspores consist propagules
of many plant species
• Fertilisation is needed (P, N, also K)
How to assess the restoration success?
Results of self-restored
Sphagnum-dominated system.
•
•
•
•
Study sites:
Kõrsa and Raessaare – two
damaged peatlands where the
transition from bare peat to
Sphagnum-dominated system has
been lasted ca 30 years.
The control sites:
Hummock communities on the
untouched Ruunasoo and Nigula
bogs.
Kõrsa site
Raessaare site
1968
Raessaare cranberry
plantation in 1972
... and 30 years later
R4
R5
2004
R6
Nigula bog
Biomass accumulation at the Kõrsa, Raessaare
and Nigula sites
•
•
Total amount of “new biomass” varies between 4085 g dm-2, the amount of organic matter in the
hummock’s acrotelm on the old bog (Nigula) is
about 200 g dm-2.
Considering that re-vegetation started some 20-25
years ago, the annual accumulation rate of the “new
biomass“ is about 2.0-3.5 t ha-1 (in average 2.7 t
ha-1), on a bog ca 2.5-7.5 t ha-1. It was not
dependent on site conditions or Sphagnum
species.
Plant cover in the ordination space - NMS general relativization
Kõrsa (K), Raessaare (R) as sites
with self-restored Sphagnum
carpet and Ruunasoo (B) as
natural bog hummocks: water
level and conductivity gradients
determine the species distribution.
The three sites are well separated.
Plant cover analyses on hummocks in
the ordination space – Canopy
and conductivity determine the
distributional pattern of analyses
in the ordination space
For conclusions
The results demonstrate that, nevertheless
the self-restored sites can be well revegetated, the species richness can’t be
achieved the level of a natural bog even
after 30 years.
Likely the formation of a functional acrotelm
needs longer time.
Acknowledgements
• The support from Estonian Environmental
Investment Centre and Estonian Ministry
of Education and Science (grant
0280009s07) is acknowledged
Thank you!
Thanks to my collegues!
From back – Laimdota Truus, Kairi Sepp,
Raimo Pajula!