Gunung Leuser National Park

Gunung Leuser National Park is one of the largest and most ecologically significant protected areas in Indonesia, located in the northern part of the island of Sumatra. Covering an area of approximately 7,900 square kilometres, the park straddles the provinces of Aceh and North Sumatra. It forms a core component of the Leuser Ecosystem, one of the richest expanses of tropical rainforest in South-East Asia, and is celebrated for its exceptional biodiversity and role in global conservation.

Location and Geography

Situated within the rugged Barisan Mountain Range, Gunung Leuser National Park features a diverse topography that includes steep mountains, dense valleys, river systems, and lowland plains. About 40 percent of its area lies above 1,500 metres in elevation, and its highest point, Mount Leuser, rises to about 3,119 metres above sea level. The park’s terrain encompasses various forest types, from lowland dipterocarp forests to montane and sub-alpine vegetation, as well as peat swamps and freshwater lakes.
The park acts as a vital watershed for northern Sumatra, feeding numerous rivers that supply water for agriculture, fisheries and human consumption. Its mountainous areas create varied microclimates, supporting distinct ecological zones and sustaining both tropical lowland and montane species.

Biodiversity and Ecosystems

Gunung Leuser National Park harbours an extraordinary diversity of flora and fauna. It is estimated to contain thousands of plant species, including many that are endemic to Sumatra. Notable plant species found here include the world’s largest flowers, Rafflesia arnoldii and Amorphophallus titanum, both of which produce enormous and rare blooms characteristic of Sumatran rainforests.
The park is one of the few remaining places on Earth where Sumatran orangutans, Sumatran tigers, Sumatran elephants, and Sumatran rhinoceroses coexist in the wild. This remarkable overlap of four critically endangered large mammals makes Gunung Leuser globally significant for conservation biology. Other species include clouded leopards, sun bears, macaques, gibbons, hornbills, kingfishers, and a vast array of amphibians, reptiles and insects.
The wide variety of habitats—from high-altitude forests to swampy lowlands—supports intricate ecological relationships. Rivers and wetlands inside the park act as breeding grounds for many aquatic organisms, while the dense forest canopy provides food and shelter for frugivorous birds and mammals.

Historical Development and Protection

Gunung Leuser was first recognised as a protected area in the early 20th century under Dutch colonial administration. It was officially declared a national park in 1980, consolidating earlier conservation zones into a single unit. In 2004, it became part of the Tropical Rainforest Heritage of Sumatra, a UNESCO World Heritage Site that also includes Kerinci Seblat and Bukit Barisan Selatan National Parks.
The park is named after Mount Leuser, a prominent peak within its boundaries. Over the years, it has become a key site for research, environmental education, and ecotourism. Numerous international and local organisations collaborate to safeguard its forests and promote sustainable development in surrounding communities.

Conservation Importance and Threats

Gunung Leuser National Park is often described as the “lungs of Sumatra,” owing to its vast forest cover and critical role in maintaining the island’s ecological balance. It provides essential ecosystem services such as carbon sequestration, soil conservation, and water regulation.
However, the park faces numerous threats:

• Deforestation and habitat fragmentation caused by illegal logging, agricultural expansion, and infrastructure development, especially for palm-oil plantations.
• Poaching and wildlife trade, which target endangered species like orangutans and tigers.
• Encroachment and human settlement, leading to conflicts between wildlife and local communities.
• Climate change, altering rainfall patterns and increasing the risk of landslides and forest fires.

Conservation efforts aim to strengthen protection, restore degraded forests, and improve law enforcement. Wildlife corridors are being established to connect fragmented habitats and ensure the survival of wide-ranging species.

Ecotourism and Community Participation

Ecotourism serves as an important conservation and economic tool in Gunung Leuser National Park. The most popular entry point is Bukit Lawang, a riverside village renowned for orangutan viewing and rainforest trekking. Another key gateway is Ketambe, located in the Aceh region, which offers a quieter and more pristine wilderness experience.
Visitors can engage in guided treks, river tubing, camping, and wildlife observation. Responsible tourism initiatives encourage minimal impact on the environment while generating income for local communities. Involving local residents in ecotourism, park management, and conservation education has proven vital for long-term protection of the ecosystem.

Ecosystem Services and Human Benefits

Beyond its biodiversity, Gunung Leuser provides essential ecosystem services to millions of people living in northern Sumatra. It regulates water flow, prevents soil erosion, and reduces flood and drought risks. The forests act as natural carbon sinks, contributing to climate stability and supporting Indonesia’s environmental commitments.
For surrounding communities, the park offers resources such as medicinal plants, forest products, and cultural inspiration. It holds spiritual significance for many indigenous groups, representing a living link between human culture and natural heritage.

Significance and Future Outlook

Gunung Leuser National Park remains a cornerstone of tropical rainforest conservation in Asia. Its protection is not only crucial for the survival of endangered Sumatran species but also for maintaining ecological balance across the region. Continued collaboration between government agencies, conservation organisations, scientists, and local communities is essential to address the growing pressures of deforestation and development.