of harvesting. However, the number of fallen trees did not decrease, and as a result,
the harvesting period was shortened even further to 4 years. In addition, fertilizer
was applied during planting to prevent fallen trees and enhance yield.
Based on the above trials and errors, plantation companies have established their
planting techniques on peatlands. Additionally, these trial and error experiences have
led to strong opposition to laws issued since 2014 to maintain the GWL of 40 cm
(ex. P.71/2014). Thus, it has been argued that at the GWL of 40 cm, plantation trees
would die or fall because their roots would be submerged in water before they
become mature. Conversely, it is also true that by lowering the groundwater table
significantly, the soil moisture content would also drop, drying out the soil and
causing peat fires.
3.11.3 Peat Soil Protection
Peat is a vulnerable material, and in the natural state, it has a high infiltration
capacity, hydraulic conductivity, low bulk density, and bearing capacity.
When plantation trees are cut down, log extraction activities cause severe compaction and degradation of the peat, which significantly affects the forest plantation
business’s sustainability. Soil compaction due to pressure on the peat surface by
heavy equipment can easily lead to significant surface irregularities and
microtopographic changes caused by soil erosion. The impact on peat characteristics
changes the peat structure, especially the peat bulk density, porosity, and millimetersized pore volume. As the peat bulk density increases due to the soil compaction and
infiltration capacity and the hydraulic conductivity decreases, and groundwater flow
and nutrient transport dynamics are changed. Additionally, the occurrence of ground
surface irregularities and reduced infiltration due to compaction can lead to partial
waterlogging and finally make planting extremely difficult.
To avoid these problems, the trials and errors of the plantation companies in
Indonesia have led to the introduction of relatively lightweight machines; the heavier
machines are strictly regulated so that they can only be moved along a certain route.
When the logs are extracted, these heavy machines must move in a straight line and
return in the same straight line. Thus, they are not allowed to move freely over the
peat. Moving branches and leaves out of the plantation after felling has been
prohibited to allow the retention of nutrients in the peat soil. The removal of
plantation tree stumps has also been banned, which would damage the peat soil
ground surface.
As described above, WSL-MTI has been focusing on the preservation of
peatlands by paying close attention to the process from planting, harvesting to log
extracting.
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T. Kato et al.
the harvesting period was shortened even further to 4 years. In addition, fertilizer
was applied during planting to prevent fallen trees and enhance yield.
Based on the above trials and errors, plantation companies have established their
planting techniques on peatlands. Additionally, these trial and error experiences have
led to strong opposition to laws issued since 2014 to maintain the GWL of 40 cm
(ex. P.71/2014). Thus, it has been argued that at the GWL of 40 cm, plantation trees
would die or fall because their roots would be submerged in water before they
become mature. Conversely, it is also true that by lowering the groundwater table
significantly, the soil moisture content would also drop, drying out the soil and
causing peat fires.
3.11.3 Peat Soil Protection
Peat is a vulnerable material, and in the natural state, it has a high infiltration
capacity, hydraulic conductivity, low bulk density, and bearing capacity.
When plantation trees are cut down, log extraction activities cause severe compaction and degradation of the peat, which significantly affects the forest plantation
business’s sustainability. Soil compaction due to pressure on the peat surface by
heavy equipment can easily lead to significant surface irregularities and
microtopographic changes caused by soil erosion. The impact on peat characteristics
changes the peat structure, especially the peat bulk density, porosity, and millimetersized pore volume. As the peat bulk density increases due to the soil compaction and
infiltration capacity and the hydraulic conductivity decreases, and groundwater flow
and nutrient transport dynamics are changed. Additionally, the occurrence of ground
surface irregularities and reduced infiltration due to compaction can lead to partial
waterlogging and finally make planting extremely difficult.
To avoid these problems, the trials and errors of the plantation companies in
Indonesia have led to the introduction of relatively lightweight machines; the heavier
machines are strictly regulated so that they can only be moved along a certain route.
When the logs are extracted, these heavy machines must move in a straight line and
return in the same straight line. Thus, they are not allowed to move freely over the
peat. Moving branches and leaves out of the plantation after felling has been
prohibited to allow the retention of nutrients in the peat soil. The removal of
plantation tree stumps has also been banned, which would damage the peat soil
ground surface.
As described above, WSL-MTI has been focusing on the preservation of
peatlands by paying close attention to the process from planting, harvesting to log
extracting.
128
T. Kato et al.