22.1 Introduction
Peatlands are water-saturated lands that provide a variety of ecosystem services and
biodiversity (Rieley et al. 2008). Riau Province has peatland areas sizing up to 4.04
million hectares or 56.1% of the total peatland area in Sumatra (Murdiyarso et al.
2004). Nowadays, human activities such as the establishment of drainage are
increasing, causing peatlands to degrade significantly (Page and Baird 2016; Koh
et al. 2011; Huijnen et al. 2016). In general, undisturbed peatlands in natural
conditions consist of almost 90% water and the remaining other 10% constitutes
the residues of wet and moist decomposed plant materials. Improper drainage system
in peatlands causes the groundwater level to drop dramatically, rendering the
peatland dry and making it susceptible to frequent fire (Hooijer et al. 2012; Ritzema
et al. 2014).
Peat soil is a type of soil that has the ability to absorb high amount of water.
Therefore, the sustainability of peat soils and other environmental services is largely
determined by appropriate water management, indicating that a good practice of
water management is necessary. The utilization of peatlands must be done wisely to
avoid damage, especially in the form of fire during a drought in peatlands. Land
clearing practices followed by the construction of drainage canals, especially on the
peat dome, have led to excessive drainage and serious peat degradation.
Degraded peatlands need to be restored through the appropriate restorative
management strategies and techniques (Hobbs and Cramer 2008; Aronson et al.
2010). The restoration efforts with hydrological management by revitalizing drainage through canal blocking may become a key strategy to reduce peatland degradation. Rewetting peatland by regulating the groundwater level (GWL) is aimed at
maintaining peat as a wetland ecosystem that will remain moist even in the dry
season, and thus minimize the risk of fire. High moisture levels will maintain the peat
structure and reduce the risk of peat fire, but conversely the low moisture levels will
result in a fragile and flammable peat structure (Syaufina 2008).
Peatland is formed by an arrangement of organic material layers including leaves,
branches, twigs, or roots in a waterlogged environment with low level of oxygen and
high acidity for a long time. Peat is composed of organic layers whose thickness may
reach up to dozens of meters (Konsorsium Central Kalimantan Project 2008).
Drainage canal construction, or often referred to as a canal, has been carrying on
for quite a long time in the area of Sungai Tohor Village, Tebing Tinggi Island, Riau,
Indonesia, and rendered the peatlands dry. The canal construction may become the
primary cause of this dried peatland, making it susceptible to fire. Forest fire
becomes one of the disturbances in the forest, disrupting various functions and
benefits of the peat forest, especially its hydrological function. Fire affects the
peatlands. It will deplete the organic matter in peat soils, impacting the thickness
of the peat. Fire will heat the air on the surface of the ground, resulting in the
decrease of relative humidity of peat soils and promote the rate of water evaporation
(soil water). This was observed during the big fire occurrence in a prolonged dry
season of 2014. An effort was implemented in 2015 to prevent future fire in this area
614
S. H. Silviana et al.
Peatlands are water-saturated lands that provide a variety of ecosystem services and
biodiversity (Rieley et al. 2008). Riau Province has peatland areas sizing up to 4.04
million hectares or 56.1% of the total peatland area in Sumatra (Murdiyarso et al.
2004). Nowadays, human activities such as the establishment of drainage are
increasing, causing peatlands to degrade significantly (Page and Baird 2016; Koh
et al. 2011; Huijnen et al. 2016). In general, undisturbed peatlands in natural
conditions consist of almost 90% water and the remaining other 10% constitutes
the residues of wet and moist decomposed plant materials. Improper drainage system
in peatlands causes the groundwater level to drop dramatically, rendering the
peatland dry and making it susceptible to frequent fire (Hooijer et al. 2012; Ritzema
et al. 2014).
Peat soil is a type of soil that has the ability to absorb high amount of water.
Therefore, the sustainability of peat soils and other environmental services is largely
determined by appropriate water management, indicating that a good practice of
water management is necessary. The utilization of peatlands must be done wisely to
avoid damage, especially in the form of fire during a drought in peatlands. Land
clearing practices followed by the construction of drainage canals, especially on the
peat dome, have led to excessive drainage and serious peat degradation.
Degraded peatlands need to be restored through the appropriate restorative
management strategies and techniques (Hobbs and Cramer 2008; Aronson et al.
2010). The restoration efforts with hydrological management by revitalizing drainage through canal blocking may become a key strategy to reduce peatland degradation. Rewetting peatland by regulating the groundwater level (GWL) is aimed at
maintaining peat as a wetland ecosystem that will remain moist even in the dry
season, and thus minimize the risk of fire. High moisture levels will maintain the peat
structure and reduce the risk of peat fire, but conversely the low moisture levels will
result in a fragile and flammable peat structure (Syaufina 2008).
Peatland is formed by an arrangement of organic material layers including leaves,
branches, twigs, or roots in a waterlogged environment with low level of oxygen and
high acidity for a long time. Peat is composed of organic layers whose thickness may
reach up to dozens of meters (Konsorsium Central Kalimantan Project 2008).
Drainage canal construction, or often referred to as a canal, has been carrying on
for quite a long time in the area of Sungai Tohor Village, Tebing Tinggi Island, Riau,
Indonesia, and rendered the peatlands dry. The canal construction may become the
primary cause of this dried peatland, making it susceptible to fire. Forest fire
becomes one of the disturbances in the forest, disrupting various functions and
benefits of the peat forest, especially its hydrological function. Fire affects the
peatlands. It will deplete the organic matter in peat soils, impacting the thickness
of the peat. Fire will heat the air on the surface of the ground, resulting in the
decrease of relative humidity of peat soils and promote the rate of water evaporation
(soil water). This was observed during the big fire occurrence in a prolonged dry
season of 2014. An effort was implemented in 2015 to prevent future fire in this area
614
S. H. Silviana et al.