occurring at an alarming rate both within and outside protected areas (Nelleman et al. 2007; Gaveau et al. 2009; Laumonier et al. 2010) and only 29% of the island is still covered in forest (WWF 2010). Between 1985 and 2007, 49.3% of all forests on the island were lost. In the provinces of Aceh and North Sumatra the fig- ures were 22.7% and 43.4%, respectively. Although the annual- ized percentage of forest loss was highest during the 1985-1990 period for both provinces (Aceh 2.0%, North Sumatra 4.2%) and decreased during 1990-2000 (Aceh 0.7% and North Suma- tra 1.2%), forest loss increased again from 2000-2008/9 (Aceh 0.9%, North Sumatra 2.3%: WWF 2010, (Map 8)). Tis trend of increased recent deforestation is not unique to Sumatra, but is observed for the whole of Indonesia where annualized deforesta- tion was high for the 1990-2000 period (1.75%), decreased for the 2000-2005 period (0.31%) and then increased from 2005- 2010 (0.71%, FAO 2010).
If only the most important orangutan habitat is examined – i.e. forest below 1,000 m – for the 1985-2007 period, the rate of loss was even higher, at 28% and 49% for Aceh and North Suma- tra respectively. When only the most species-rich forests (below 500 m) are considered, forest loss between 1985 and 2007 was 36% for Aceh and 61% for North Sumatra. For the carbon- rich peat swamp forests the loss was 33% for Aceh and 78% for North Sumatra (Figure 1).
Road development Development of Sumatra’s transport infrastructure, especially roads, is seen by many in Indonesia as a prerequisite to increas- ing economic growth (Saroso 2010). But it is also one of the most serious threats to Sumatran orangutan habitat and to the viability of remaining wild populations. Construction of new roads opens up access to previously inaccessible areas and leads to the expansion of human activities along their length. By facilitating the movement of people into new areas, roads di- rectly result in damaging activities such as hunting, logging and
Figure 1: Forest loss from 1985-2007 for the whole island of Sumatra, and Aceh and North Sumatra separately. Calcula- tions were based on Laumonier et al. (2010) and WWF (2010).
30
A truck filled with iron ore travels a newly opened road through the forest in South Aceh (Perry van Duijnhoven)