The Leuser Ecosystem spans the provinces of Aceh and North Sumatra on the island of Sumatra in Indonesia. Over 35 times the size of Singapore, this majestic and ancient ecosystem covers more than 2.6 million hectares of lowland rainforests, peat swamps, montane and coastal forests, alpine meadows and cultivation areas. Globally recognized as one of the richest expanses of tropical rainforest found anywhere in Southeast Asia, the Leuser Ecosystem is also one of Asia’s largest carbon sinks.

The last place on Earth

The Leuser Ecosystem is the last place on earth where sumatran orangutans, rhinos, elephants, and tigers co-exist in the wild. Sadly all four of these species are now classified by the International Union for Conservation of Nature (IUCN) as Critically Endangered. The Leuser Ecosystem is the only remaining habitat left in Sumatra large enough to sustain viable populations of these species.

A publication in leading international journal of science listed the Leuser Ecosystem as “one of the world’s foremost irreplaceable areas”.  

Conservation efforts date far back

Efforts to conserve the Leuser Ecosystem date as far back as the early 19th century, when the traditional leaders of Aceh lobbied the colonial government to protect their natural heritage, ranging from the mountains all the way down to the coast. More recent laws have served to strengthen the protection of the Leuser Ecosystem and placed the responsibility for managing its protection and restoration with the Aceh Provincial Government (Article 150 of National Law on Governing Aceh No. 11/2006).

Furthermore, the Leuser Ecosystem has special legal status as a National Strategic Area for its Environmental Protection Function (26 of 2007 Juncto 26/2008). The Leuser Ecosystem Area (KEL) has been designated a Biosphere Reserve by MAB - UNESCO, as a buffer zone for the Gunung Leuser National Park. 

The environmental and economical benefits of the Leuser Ecosystem are inextricably linked. The Leuser Ecosystem is an essential asset for the economic development of Aceh providing a total economic value of at least 350 million US dollars per year.

The Leuser Ecosystem acts as a life-support system for approximately four million people in Aceh. The primary ecosystem services are the freshwater provision and disaster mitigation. The forests of the Leuser Ecosystem act like a sponge to soak up the downpours of the rainy season and spread out the release of water downstream more evenly across the months.

This regulates the water supply to prevent prolonged droughts ensuring a reliable source of fresh water for sustaining the local rice-growing cultures, other agriculture, and fisheries as well as for drinking, bathing and transportation. The ecosystem also provides non-timber forest products such as rattan, bamboo, and wild fruits, which are harvested by local communities.

Immense environmental value

Deforestation in this environmentally sensitive area is exacerbating the devastation caused by flooding and landslides. The removal of forest cover leads to heavy rainfall carrying mud and debris into water systems, which in turn washes out roads, floods villages, and inflicts significant economic damage on both local communities and downstream industries. Moreover, the Leuser Ecosystem holds immense environmental value on both national and international scales due to its critical role in climate regulation and carbon storage.