Lógica de control de bomba

Preliminary results of elemental carbon analysis on peats from Danau Sentarum and Rasau Jaya are depicted in Figure 2. This analysis shows that carbon contents from forested peatland in Danau Sentarum are substantially higher than that from open peatland in Rasau Jaya. However, the laboratory results of carbon contents from peatlands in Danau Sentarum and Rasau Jaya did not show statistically signifi cant differences (Armiyarsih 2005). This indicates that all peatlands are important sites for carbon storage. And the importance of carbon storage in peatlands is greatly determined by peat depths and varying degrees of peat growths.

Figure 2. Carbon contents in top layer (50 cm) from forested peatlands (N and K) of Danau Sentarum, and open peatlands (B and K) from Rasau Jaya (Source: Armiyarsih 2005).

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In the absence of human disturbance and under wet climatic condition, the rates of tropical peat and carbon are often accumulated faster than boreal and temperate peats. In Central Kalimantan, the rate of peat accumulation in the Sebangau River is ~ 0.4-2.2 mm yr-1_{, and the rate of long-term carbon accumulation is estimated}

to be 56 g C m-2 _yr-1_{. This data is derived from a 980 cm core, with a basal date of}

around 20,000 14_{C yr BP (Page et al. 2004). The rate of peat accumulation in Danau}

Sentarum is fairly slow, ranging from 0.2-0.4 mm yr-1_{, comparable to the rates of}

boreal, artic, and temperate peat accumulation, about 0.2-1.0 mm yr-1_{(Aaby and}

Tauber 1975; Gorham 1991).

It is important to mention here that the origin of peat is an important factor that infl uences peat growth. The growths of peat originating from kerangas or kerapah seem to be slower than those of from freshwater and mangrove forests. In addition, rapid peat loss in Danau Sentarum might also occur because of logging, fi re, and prolonged dry seasons. As the removal of forests in Danau Sentarum catchments area becomes so intensive, this region more frequently dries, turning an aquatic, waterlogged environment into terrestrial, bushland environment. In Rasau Jaya Region, where peatland agriculture takes place, rapid peat loss occurs due to fi re and over-drainage. The amount of carbon loss from every cm peat layer is estimated to be between 3 and 6 tons C ha-1_.

Peatland forests in Danau Sentarum play many functions. Timber, wildlife, and non-timber forest products (especially wild honey, resins, and rattan) are commonly extracted by local communities. In addition, peatland is absolutely important for regulating water quantity and quality. Peat is known to be able to retain a lot of water, up to 1000% of its dry weight. In Danau Sentarum, peatland and other swamp forests play a signifi cant role in providing foods (seeds and nuts) for fi sh. Humic acids released from peat may also be essential for enriching nutrient availability in this oligotrophic environment. These food webs and nutrient cycles are thought to be important for maintaining fi sh population in Danau Sentarum National Park. Local communities state that the loss of peatland forests is linearly associated with the decline of fi sh catches in Danau Sentarum National Park. Over-exploitation in peatland forests in Danau Sentarum National Park seems to be a major cause of livelihood decline (Anshari 2004). A model that depicts a link between the destruction of peatland forest and livelihood decline is described in Figure 3.

In open peatland of Rasau Jaya, the use of fi re during seedbed preparation has caused substantial peat loss, and over-drainage caused rapid peat subsidence. Every year, it is estimated that between 2 and 5 cm of peat layer may be lost by fi re, and the rate of peat subsidence is at least 1 cm yr-1_{. The abandoned peatland is then infested}

by ferns. According to Anshari (2003), ash derived from the fi re on fern biomass does not substantially improve peat soil fertility. This may explain why farmers leave the site after one cycle of farming. Also, these open peatlands, which are recently colonized by fern species, have lower water capacity than forested peatlands. As a result, open peatlands seem to function as a water depleting ecosystem, especially in dry season (Anshari 2003). The result of water content analysis, using ring samples, shows high values in forested peatlands in Danau Sentarum (544-818%), and low values in open peatlands in Rasau Jaya (282-325%). Under these circumstances, present peatland agriculture practice is not sustainable.

Gusti Z. Anshari and Armiyarsih | 119

Efforts to control the decline of forested peatland in Danau Sentarum and to introduce wise practices in peatland agriculture have been tried. To slow the rate of peat loss and subsidence, it is important to ban the use of fi re in peatland agriculture, and at the same time to maintain a high water table. It is widely known that fi re use in peatland agriculture aims to produce ash that would improve peat soil fertility. Alternatives to ash, lime and ocean mud could be used. Lime is not locally available, expensive and detrimental to soil and water. Ocean mud is a good ameliorant to improve peat soil fertility. Studies show that ocean mud could mix with peat fractions and improve peat soil fertility by increasing pH and base saturation, and adding some macro- and micronutrients (Pujianto 1993; Maulidia 1995; Suyadi 2003; Rianto et al. 1996; Latief 2003). There are some diffi culties in this practice. First, ocean mud is relatively heavy, causing a major problem for poor farmers to transport the material to the farm. Second, the ocean mud is collected from the beach, quite far from the peatland agriculture site (about 70 km away). Third, there is still lack of promotion of this practice, and there is no market value to ocean mud. As a result, it is diffi cult for policymakers to determine an appropriate price to adopt this practice (Anshari et al. 2003).

Figure 3 shows that Danau Sentarum National Park is not carefully managed in terms of securing local community livelihoods. At present, the management authority of the park is under the Department of Forestry (i.e. BKSDA Kalimantan Barat). This central government agency has little capacity and budget to manage this wetland of international importance. As the management authority is centrally granted, local governments (both the West Kalimantan province and Kapuas Hulu district) avoid taking part in the management of Danau Sentarum National Park. As a result, mismanagement of the park creates a condition of open access, which provides opportunities for outsiders to come and exploit park resources. All timber extraction in Danau Sentarum is inspired and sponsored by outsiders who have the potential to destroy the integrity of the park’s ecosystem. As the infl uence of global markets increases, local communities in Danau Sentarum National Park have also been short of institutional mechanisms to protect their long-term interests, and get more interested in short-term gains. Most members of these communities tend to act on the basis of individual gains. The destruction of peatland and other park resources clearly diminish livelihoods of local communities, particularly the poor. In line with natural resource destruction, poor management leads to local elites securing natural resources to protect their individual interests. In the near future, some locals will set fi re to land, plant commercial crops, and then claim it as a private property. This strategy can be seen everywhere in the tropics, especially when land tenure is not clearly defi ned, local institution is weak, and customary laws are not enforced.

120 | Carbon Decline