dicinal purposes, and agarwood (Aquilaria malaccensis), which, in response to a fungal infection produces a highly prized resin, used for incense and perfumes), firewood, the regulation of diseases such as malaria, West Nile virus, lyme disease and diarrhoeal diseases (Allan et al. 2003; LoGiudice et al. 2003; Ezenwa et al. 2006; Pattanyak and Wendland 2007; Vittor et al. 2006, 2009; Yasmine 2010).
Buffer zone against tsunamis Te December 2004 tsunami caused incomprehensible damage and devastating losses in human life in Aceh, with over 150,000 people dead or missing, over 500,000 left homeless, 127,000 houses destroyed and a similar number damaged, 230 km of roads destroyed (World Bank 2005), damage to over 37,500 hectares of land and 90% of surface corals damaged or destroyed (FAO/WFP 2005).
Aceh’s coastal peat swamp forests of Tripa, Singkil and Klu- et acted as efficient, natural, protective buffer zones, behind which hardly any casualties were recorded. Only those com- munities living directly on exposed, non-forested coastal stretches of the swamps suffered any casualties. Kuala Tripa, the small coastal village at the north-western tip of the Tri- pa swamp, was affected, as were several other villages in the adjacent sub-districts of Kuala and Darul Makmur. A total of 493 people died along this stretch of coastline, all from exposed and unprotected villages along the shoreline itself (Aceh Pedia 2010).
In recognition of the role that forested areas like Tripa, Kluet and Singkil play in preventing settlement and encroachment of human populations in vulnerable coastal areas, the Indonesian government’s Post-tsunami Master Plan (Republic of Indonesia 2005) specifically called for the development of a coastal green- belt buffer zone.
Regulation of coastal shorelines Te coastal peat swamp forests are on peat domes that main- tain a high water table, preventing sea water intrusion into the swamp itself (Wösten et al. 2006, 2008). When peat swamps are drained for plantations, and the peat dries and oxidizes, it shrinks, resulting in subsidence of around five centimetres per year in the first few years, according to even the most conserva- tive scenarios, which then stabilizes at around two centimetres a year (Wösten and Ritzema 2002; Hooijer et al. 2006). Subsid- ence near the coast leads to the serious problem of increasing land salinity, which will eventually preclude agricultural produc- tion, even on the oil palm plantation areas themselves. With global sea levels also predicted to rise (IPCC 2007), this poses serious risks of coastal erosion and increases the potential im- pact of future disasters like the 2004 tsunami.
Total potential value of primary forest on peat and non-peat lands compared to other land uses To evaluate various spatial planning scenarios in relation to the potential for economic development it is important to de- termine the value of various land uses. For the purpose of this study, they are presented as the net present value for several of the main land-use options. Te area where orangutans occur can be separated into two main habitat types: forest on peat- lands (Tripa) and forests on mineral soils (Batang Toru), and
Newly planted oil palm trees (Nick Lyon/Cockroach Productions)
the results are presented for these types separately (Figure 5). For forests on non-peat lands the range of net present values for forest in terms of avoided deforestation ranges from USD 3,711-11,185 /ha for a 25 year period. Tis value is higher than that for all other land uses assessed (agroforestry, sustainable logging, coffee, etc), but overlaps with that of oil palm (NPV USD 7,832 /ha). For forests on peatlands the range of values for avoided deforestation (USD 7,420-22,094 /ha over a 25- year period) are again higher than all other land uses and also nearly entirely exceeding the range of values for oil palm plan- tations (USD 7,832 /ha over 25 years).
Tese values can subsequently be used to reflect upon past land use changes in areas where orangutans occur and on potential future scenarios. Because the vast majority of the orangutan distribution is in the Leuser Ecosystem (78%), the focus is on that area.
Past During the 1985-2007 period, deforestation in the Leuser Ecosystem was 297,512 ha, of which 30,681 ha was on peat soil and 266,831 on mineral soil. Tis amounts to an overall 11.7% loss of forest; 20.1% of forest on peat soil and 11.2% of forest on mineral soil. Te values for forests on mineral soils are relatively low because almost half of these forests are above 1,000 m where 3.7% of the forest was lost between the 1985-