Indications of compaction in relation to subsidence on peatlands used for accacia crassicarpa plantation in Indonesia
The 14th International Peat Congress
Pe atlands in Balance
Stockholm, Sweden
June 3-8, 201 2
International Peat Society I IfI,TG セitc@
14th International Peat Congress
.....m." .....""'.."''''
abstract No. 115
INDICATIONS OF COMPACTION IN
FOR ACCACIA Ln.f"""
TO
ON PEATLANDS
PLANTATION IN INDONESIA
of Agriculture, Bogor
Department Soil Science
Land Resources,
Agricultural University;
Campus, 1
Bogor, mo,oneSla, +620251
dannawan_soil@yahoo.com
Dwi
Baskoro and
Nugroho;
of Soil Science and
Resources,
Faculty of Agriculture, Bogor Agricultural University
Land subsidence will always
when peatlands are drained.
subsidence is
predicting Carbon emission from
One year subsidence monitoring as well as
measurement of bulk
and size
of the organic materials was
out at several
of peatlands in
used for
crassicarpa plantation. The subsidence rate during
the
was found to be
since the land
were
to alternately
down. Peat
above water table are
by fine
that general
corresponded
higher bulk
but the higher bulk density is
to be
straightforwardly interpreted as an indication of compaction, because it depends on the historical
...U«11I">.... of the peatlands.
Keywords: Emission,
...""U Tl/1,,,,
1
SubSidence, re(manas
INTRODUCTION
to agriculture as well as to
forest in
"""r,,,n" of tropical
become a
environmental
with
to carbon emission to
atmosphere.
are
many publications presenting data of the emission obtained from mathematical estimates
use
subsidence as a
parameter.
that
involves consolidation, compaction,
decomposition (Andriesse, 1988) and
ofland materials, it is of great importance to fully
rI""r,oh.... rI how far the subsidence would
Understanding
and rate
subsidence will give
contribution
material
to
the
and hence
understanding
emission.
ll.UVU''';.....
work (Kool et
Measurement of compaction is not an
to correlate
increasing bulk density (BD), theret,oremeasuring
of peat layer is
done for this
the other
compaction likely correlates with
of organic
material
of peat,
the finest the
the highest compaction would happen.
1
International Peat Congress
locations Sumatra Island, Indonesia.
location is in
plantation area directly
810
from
peatland
deep peat.
location is Jambi
also within an
cracicarpa plantation on a moderate peat depth which area was previously logged.
third is
located in
Sumatra
on shallow peat depth which area is denuded and has
subjected to
burnings and over
from the surrounding.
at three
one plot
the
neighboring pristine peatland forest, at one plot in
location
an additional plot
within a
and two plots in the third location. The monitoring
was run a year at 1
interval. At plots, the
surface level was measured
perforated
tube as poles inserted vertically through the
and anchored the ------J
mUtleral sediment.
this perforated PVC water table was monitored as
Measurement ofBD was done at plots of the subsidence monitoring
first location
one plot in second and third locations. The BD samples were collected from
pits using topdown open
box with 10 em x 10 em x 10 em dimension. Sampling was done
depthwisely
to around water table.
were collected for ,,,"nr'rt>
into sizes of UPセャ@
by
samples with 0.1 M Sodium pyrophosphate
followed by sequential wet
respective
of sieves.
"VUI'.Hll:Z.
AND DISCUSSION
1 shows that subsidence rates
plantations on deep peat over a year
was unclear.
plot
9 years plantation shows a subsidence of about 2 em after a year. In
the contrary plot'ofthe 6
plantation
a
surface level instead of subsidence.
Rising and
surface
alternately happen and is
for all the measurement
..."'.........'15 that
pristine
Among
considered to have
with
process, it seems that the
(peat)
parameter
a
significant correlation. The correlation is even quite
forest plot.
possible
explanation of this correlation is that the increasing and
soil moisture content to a
considerable extent made peat material to swell and
respectively.
plantations on the shallower peat
2 and 3 show
subsidence rates of the A.
over a year were slightly higher than that of the
However, between the plots there are
significant variations.
lowest extent of subsidence the deep
is likely due to a steady
water table
is kept
5080 em
the surface. A sharp fall
surface is detected
2
14th International Peat Congress
at the plot of new ly started plantation from a condition of an over drained and burnt peatland. The
drop happen just follow significant lowering of t he water table (Fig. 3 a). This anomaly is hard to
explain but it may be attributed to a sharp increase in decaying process of wood remnants below
the surface by termites during the low water table period.
9 years A. crass/carp a Plantation on Deep Peat
300
250
1]
·4
·6
サᄃセ@
150 ァ[ZMセ@
·8
·10
· 12
· 14
· 16
18
·20
'"
"
200
セZエ@
100 'I!I
•
•
Month
.
•
"
'"
50
0
Rainfa ll
Wa te r Table
A. Crass ica rpa plot 1 A. Crassica rpa plo t 2
.
A. Crassica rpa p lo t 4
Soil M oisture
... A. Crassi ca rpa plot 3
(0)
6 years A. erossicorpo Plantation on Deep Peat
0
2 0
:[
4
g
e:
6
'C
8
N セ@
.D
セ@
300
.. -- - -.-
..
10
12
1 4
16
18
·}O
",. .,.. ._ ,
....... .
.... .
-
• • •
50
•
o
Month
Water Tabl e
セ M A_ c rassicarp a plot 1 da n 2 (b)
Rai nfa ll
So il Moisture
..... .... A. crassica rpa .p lo t 3
Pristine Forest
. 4
800
700
I, 600
.
'"
soo
セ@
,?E;if
............. /
400 eセウ@
/
300
· 14
200
· 16
=3:"'
Nセ@
0:
100
18
·20
セ@
_
r&1 ...... セ
N@ ''''',:::.''':! ..... セ . . .... L セ セG@ ....•,. ..... エ セG@
o
Month
Ra infa ll
.. .... .. .. W at er Table
- . - Soil M oisture
- .. - Pri stine Fo res t
Ie)
Figure 1. One year subsidence monitoring on A. crassicarpa planted deep peat and of adjacent pristine forest.
3
14th International Peat Congress
A. Cfassicarpa Plantation on Moderate Peat
Secondary Forest
(ex logged·over area)
650
o \ \
0\ } Z 3...... 4 セGU@
\ \ ...... ""
__
セGR@
...
セ@
·10 I M
セ
GMB
..
N@
·12
c
セ@
\
·4
-
_
M ᄋ セw。エ・イ
Rainfall
セMe
350
.\. . . .'. . _.⦅M N セNML@
.g .
AN[Zセ@
E u
セ@
f
::: 1セ@
.... セ@
10
t!
50
·50
·50
·12
Month
Month
... . .... Pipe A
450
..................1.'
6
セ@
セ@
9 10 11 12 13
r",,},
v
.()'
':;:'
c)
..., |セャ@セ@
':0
Depth (em)
C'
c)
':0
.:,
0;:'
"
0 ,
0:,
(e)
Figure 4. Bulk density and particle size fraction of A. crassicarpa planted deep peat and of adjacent pristine forest.
5
14th International Peat Congress
I ;:z;;ssicarpa Plantation on Shallow Peat
(ex over drained and burnt area)
A,Crassicarpa Plantation on Moderate Peat
(ex loggedover area)
I
· 0.14
c::=J \QPVセ@
0.12
e-
, ,
· 010
0.06'" _
· 0.04
O.Ol
L
UPNャセ@
セ@
UHQャセ@
I
0.00
r
セ
80%
70W 1
セ@ 60%·
_ 50% J
lOOO.1000p
⦅^
J
9Q'!"
c::=J 1000.1061'
· 0.08"§
j'
100%
40%
30%
lO%
10%
,
1
0.l5
c::=J \QPセL@
O.lO
」Z]jャPᄋセ@
0.151
lOOO1000I'
0.10"
5000·l000!,
0.05
>50001'
.....
_
Figure 5. Bulk density and particle size fraction of A. crassicarpa planted moderate and shallow peat.
Fig. 4 shows that BD values of the upper parts of the pristine forest plot are about 0.160.20 g cnf
crassicarpa, The reason is unclear but strongly
indicates that interpretation ofBD values of peatlands with respect to compaction cannot be
straightforward but need to check for historical disturbance or change to the lands, The use of
mathematical fonnulation such as shown in Hooijer et at. (2011) to calculate compaction using
difference ofBD values between the upper and the lower parts would, therefore, be uncertain,
3 that is higher than that of the plots of the A,
CONCLUSION
The subsidence rate during the year was found to be uncertain since the land surfaces was found
to alternately rise and down,
Peat materials above the water table are dominated by fine fractions that in general corresponded
with higher bulk density but the higher bulk density is difficult to be straightforwardly interpreted
as an indication of compaction, because it depend on the historical change of the peatlands.
ACLNOWLEDGEMENTS
We thank PT. Bukit Batu Hutani Alam, PT. Sekato Pratama Makmur , PT. Wirakarya Sakti, PT.
Sebangun BUlni Andalas, Sinar Mas Forestry Management and APP Indonesia for giving
pennission to conduct this research on their plantation forest concession areas and financial
support..
6
14th International Peat Congress
REFERENCES
Andriesse, J.P. 1988. Nature
248pp.
soils. FA peat soils. F AO JJW.l,",Yl1,
Hooijer, A., Page, S., Jauhiainen, J.,
A. and Anshari, G. 2011.
1J"'IW.a.LlU;) reducing uncertainty and implication
Subsidence and Carbon loss
for
emission reduction ODt:IOlllS. Jj'V;':;"'V"''-''
Pe atlands in Balance
Stockholm, Sweden
June 3-8, 201 2
International Peat Society I IfI,TG セitc@
14th International Peat Congress
.....m." .....""'.."''''
abstract No. 115
INDICATIONS OF COMPACTION IN
FOR ACCACIA Ln.f"""
TO
ON PEATLANDS
PLANTATION IN INDONESIA
of Agriculture, Bogor
Department Soil Science
Land Resources,
Agricultural University;
Campus, 1
Bogor, mo,oneSla, +620251
dannawan_soil@yahoo.com
Dwi
Baskoro and
Nugroho;
of Soil Science and
Resources,
Faculty of Agriculture, Bogor Agricultural University
Land subsidence will always
when peatlands are drained.
subsidence is
predicting Carbon emission from
One year subsidence monitoring as well as
measurement of bulk
and size
of the organic materials was
out at several
of peatlands in
used for
crassicarpa plantation. The subsidence rate during
the
was found to be
since the land
were
to alternately
down. Peat
above water table are
by fine
that general
corresponded
higher bulk
but the higher bulk density is
to be
straightforwardly interpreted as an indication of compaction, because it depends on the historical
...U«11I">.... of the peatlands.
Keywords: Emission,
...""U Tl/1,,,,
1
SubSidence, re(manas
INTRODUCTION
to agriculture as well as to
forest in
"""r,,,n" of tropical
become a
environmental
with
to carbon emission to
atmosphere.
are
many publications presenting data of the emission obtained from mathematical estimates
use
subsidence as a
parameter.
that
involves consolidation, compaction,
decomposition (Andriesse, 1988) and
ofland materials, it is of great importance to fully
rI""r,oh.... rI how far the subsidence would
Understanding
and rate
subsidence will give
contribution
material
to
the
and hence
understanding
emission.
ll.UVU''';.....
work (Kool et
Measurement of compaction is not an
to correlate
increasing bulk density (BD), theret,oremeasuring
of peat layer is
done for this
the other
compaction likely correlates with
of organic
material
of peat,
the finest the
the highest compaction would happen.
1
International Peat Congress
locations Sumatra Island, Indonesia.
location is in
plantation area directly
810
from
peatland
deep peat.
location is Jambi
also within an
cracicarpa plantation on a moderate peat depth which area was previously logged.
third is
located in
Sumatra
on shallow peat depth which area is denuded and has
subjected to
burnings and over
from the surrounding.
at three
one plot
the
neighboring pristine peatland forest, at one plot in
location
an additional plot
within a
and two plots in the third location. The monitoring
was run a year at 1
interval. At plots, the
surface level was measured
perforated
tube as poles inserted vertically through the
and anchored the ------J
mUtleral sediment.
this perforated PVC water table was monitored as
Measurement ofBD was done at plots of the subsidence monitoring
first location
one plot in second and third locations. The BD samples were collected from
pits using topdown open
box with 10 em x 10 em x 10 em dimension. Sampling was done
depthwisely
to around water table.
were collected for ,,,"nr'rt>
into sizes of UPセャ@
by
samples with 0.1 M Sodium pyrophosphate
followed by sequential wet
respective
of sieves.
"VUI'.Hll:Z.
AND DISCUSSION
1 shows that subsidence rates
plantations on deep peat over a year
was unclear.
plot
9 years plantation shows a subsidence of about 2 em after a year. In
the contrary plot'ofthe 6
plantation
a
surface level instead of subsidence.
Rising and
surface
alternately happen and is
for all the measurement
..."'.........'15 that
pristine
Among
considered to have
with
process, it seems that the
(peat)
parameter
a
significant correlation. The correlation is even quite
forest plot.
possible
explanation of this correlation is that the increasing and
soil moisture content to a
considerable extent made peat material to swell and
respectively.
plantations on the shallower peat
2 and 3 show
subsidence rates of the A.
over a year were slightly higher than that of the
However, between the plots there are
significant variations.
lowest extent of subsidence the deep
is likely due to a steady
water table
is kept
5080 em
the surface. A sharp fall
surface is detected
2
14th International Peat Congress
at the plot of new ly started plantation from a condition of an over drained and burnt peatland. The
drop happen just follow significant lowering of t he water table (Fig. 3 a). This anomaly is hard to
explain but it may be attributed to a sharp increase in decaying process of wood remnants below
the surface by termites during the low water table period.
9 years A. crass/carp a Plantation on Deep Peat
300
250
1]
·4
·6
サᄃセ@
150 ァ[ZMセ@
·8
·10
· 12
· 14
· 16
18
·20
'"
"
200
セZエ@
100 'I!I
•
•
Month
.
•
"
'"
50
0
Rainfa ll
Wa te r Table
A. Crass ica rpa plot 1 A. Crassica rpa plo t 2
.
A. Crassica rpa p lo t 4
Soil M oisture
... A. Crassi ca rpa plot 3
(0)
6 years A. erossicorpo Plantation on Deep Peat
0
2 0
:[
4
g
e:
6
'C
8
N セ@
.D
セ@
300
.. -- - -.-
..
10
12
1 4
16
18
·}O
",. .,.. ._ ,
....... .
.... .
-
• • •
50
•
o
Month
Water Tabl e
セ M A_ c rassicarp a plot 1 da n 2 (b)
Rai nfa ll
So il Moisture
..... .... A. crassica rpa .p lo t 3
Pristine Forest
. 4
800
700
I, 600
.
'"
soo
セ@
,?E;if
............. /
400 eセウ@
/
300
· 14
200
· 16
=3:"'
Nセ@
0:
100
18
·20
セ@
_
r&1 ...... セ
N@ ''''',:::.''':! ..... セ . . .... L セ セG@ ....•,. ..... エ セG@
o
Month
Ra infa ll
.. .... .. .. W at er Table
- . - Soil M oisture
- .. - Pri stine Fo res t
Ie)
Figure 1. One year subsidence monitoring on A. crassicarpa planted deep peat and of adjacent pristine forest.
3
14th International Peat Congress
A. Cfassicarpa Plantation on Moderate Peat
Secondary Forest
(ex logged·over area)
650
o \ \
0\ } Z 3...... 4 セGU@
\ \ ...... ""
__
セGR@
...
セ@
·10 I M
セ
GMB
..
N@
·12
c
セ@
\
·4
-
_
M ᄋ セw。エ・イ
Rainfall
セMe
350
.\. . . .'. . _.⦅M N セNML@
.g .
AN[Zセ@
E u
セ@
f
::: 1セ@
.... セ@
10
t!
50
·50
·50
·12
Month
Month
... . .... Pipe A
450
..................1.'
6
セ@
セ@
9 10 11 12 13
r",,},
v
.()'
':;:'
c)
..., |セャ@セ@
':0
Depth (em)
C'
c)
':0
.:,
0;:'
"
0 ,
0:,
(e)
Figure 4. Bulk density and particle size fraction of A. crassicarpa planted deep peat and of adjacent pristine forest.
5
14th International Peat Congress
I ;:z;;ssicarpa Plantation on Shallow Peat
(ex over drained and burnt area)
A,Crassicarpa Plantation on Moderate Peat
(ex loggedover area)
I
· 0.14
c::=J \QPVセ@
0.12
e-
, ,
· 010
0.06'" _
· 0.04
O.Ol
L
UPNャセ@
セ@
UHQャセ@
I
0.00
r
セ
80%
70W 1
セ@ 60%·
_ 50% J
lOOO.1000p
⦅^
J
9Q'!"
c::=J 1000.1061'
· 0.08"§
j'
100%
40%
30%
lO%
10%
,
1
0.l5
c::=J \QPセL@
O.lO
」Z]jャPᄋセ@
0.151
lOOO1000I'
0.10"
5000·l000!,
0.05
>50001'
.....
_
Figure 5. Bulk density and particle size fraction of A. crassicarpa planted moderate and shallow peat.
Fig. 4 shows that BD values of the upper parts of the pristine forest plot are about 0.160.20 g cnf
crassicarpa, The reason is unclear but strongly
indicates that interpretation ofBD values of peatlands with respect to compaction cannot be
straightforward but need to check for historical disturbance or change to the lands, The use of
mathematical fonnulation such as shown in Hooijer et at. (2011) to calculate compaction using
difference ofBD values between the upper and the lower parts would, therefore, be uncertain,
3 that is higher than that of the plots of the A,
CONCLUSION
The subsidence rate during the year was found to be uncertain since the land surfaces was found
to alternately rise and down,
Peat materials above the water table are dominated by fine fractions that in general corresponded
with higher bulk density but the higher bulk density is difficult to be straightforwardly interpreted
as an indication of compaction, because it depend on the historical change of the peatlands.
ACLNOWLEDGEMENTS
We thank PT. Bukit Batu Hutani Alam, PT. Sekato Pratama Makmur , PT. Wirakarya Sakti, PT.
Sebangun BUlni Andalas, Sinar Mas Forestry Management and APP Indonesia for giving
pennission to conduct this research on their plantation forest concession areas and financial
support..
6
14th International Peat Congress
REFERENCES
Andriesse, J.P. 1988. Nature
248pp.
soils. FA peat soils. F AO JJW.l,",Yl1,
Hooijer, A., Page, S., Jauhiainen, J.,
A. and Anshari, G. 2011.
1J"'IW.a.LlU;) reducing uncertainty and implication
Subsidence and Carbon loss
for
emission reduction ODt:IOlllS. Jj'V;':;"'V"''-''