Gunung Leuser National Park is one of the largest protected forested areas in southeast asia, this national park encompasses a range of environments from coastal lowland to volcanic peaks. Most Sumatran wildlife species are represented in the ares, though tigers, elephants and rhinos are in evidence mainly through mud tracks, trumpet calls and rustling bushes than actual sightings. The Alas river, which traverses much of the park’s length, is often the best vantage point for viewing the park’s flora and fauna. Ecologically sensitive river rafting operation are a good option for visitors, combining whitewater excitement with river-level views of forest life and just outside the park boundaries, daily activities at river settlements. The Bohorok wildlife research station and orangutan rehabilitation center lies at the park outskirts.
The Gunung Leuser National Park (Gunung Leuser National Park) is located in northern Sumatra, Indonesia, covers approximately 1,094,692 hectares (ha) (1 ha is about the size of a football pitch), and straddles the borders of the two provinces of Nanggroe Aceh Darussalam and North Sumatra. The Gunung Leuser National Park takes its name from the towering Mount Leuser, whose peak stretches to 3,404m. The park was originally established as a 142,800 ha Indonesian Nature Reserve in 1934 (ZB No. 317/35), and after a series of additions and classification changes was formally established as a National Park in 1980 (811/Kpts/Um/II/1980).
Together with Bukit Barisan Selatan and Kerinci Seblat National Parks, the Gunung Leuser National Park forms the Tropical Rainforest Heritage of Sumatra UNESCO World Heritage Site (TRHS). The World Heritage status was inscribed in 2004, along with the previously attributed status of being recognized as a Biosphere Reserve in 1981 and an ASEAN Heritage Park in 1984. Here exists a complex, amazingly species rich and fragile environment, with a delicately balanced network of animal and plant life. The Gunung Leuser National Park is the core of many endangered species’ remaining habitat. The area is considered to be of huge environmental importance, and the unique flora and fauna are in critical need of conservation and protection. The Gunung Leuser National Park is also part of one of the WWF’s 200 Global Ecoregions of conservation importance for world biodiversity.
The Gunung Leuser National Park lies within the 2,634,874 ha Leuser Ecosystem (LE). This region was established after comprehensive research conducted in the 1980s and 90s, which showed that the borders of the national park were insufficient to maintain the requirements of the rich biodiversity present in northern Sumatra. Thus, in 1995, the LE was legally recognized through a Ministry of Forestry Decree (No. 227/KPTS-II/1995), and also a Presidential Decree in 1998 (No. 33/1998). In 2008, it was established as a national strategic area by a government regulation (No. 26/2008).
Flora of Gunung Leuser National Park
Approximately 8,500 plant species grow in the beach, swamp, lowland, mountain and alpine ecosystems of the Leuser Ecosystem, with no less than 4,000 of these growing in the Gunung Leuser National Park itself. The region represents one of the best remaining expanses of lowland dipterocarp forest across Indonesia. The trees reach 40-70m in height and are home to a great number of plant and animal species. The dipterocarp trees tend to produce exceptionally large amounts of fruit at the same time every two to five years. This is known as mast fruiting. During these years there is a vast surplus of edible fruits available for forest animals, much of which remains untouched. In normal fruiting seasons there is far less fruit than in masting periods, meaning that fruit dependent animals, such as orangutans, have to cover large distances to find enough food to survive.
The forests are home to an enormous variety of plant species, due to the soil diversity and differences in altitude. The rafflesia flower (Rafflesia arnoldii) is the world’s largest individual flower, and is found only on Sumatra and the neighbouring island of Borneo. The rafflesia flower can weigh as much as 11kg when fully grown, with its dark pink and red petals growing up to 1m long and 2.5cm thick. It is a parasitic plant and lacks any leaves, stems or roots, instead obtaining nutrients from host plants to which it attaches itself. Its rather morbid common name is the ‘corpse flower’ as it is said to emit a very pungent smell, used to attract pollinating insects within the dense forest. Casuarinas trees, wild nutmeg, camphor, nibung palms, rotan, mangrove trees, and pandan plants can all be found in the beach and swamp forests, and along the rivers grow exotic species such as Pometia pinnata. In the lowland forests, trees such as meranti, keruing, camphor and damar, along with several wild fruit trees such as durian, mango, wild banana, citrus fruit and wild jack fruit growing in abundance. The mountain and alpine woods are home to several species of moss and wild flowers such as gentians, primulas, strawberries, herbs, and wild orchids. The rafflesia flower can also be found in these forest.
The damar tree (Agathis sp.) is particularly useful to people, as it grows to great heights (greater than 20m) and can be harvested for its resin. The resin can be burned and used for starting fires and as a pleasant smelling incense. The wood of the tree is also very valuable, and timber sales can generate important revenue for local people. It also plays an important role in the local ecosystem, supporting the growth of a certain type of strangling fig. During fruiting season there can be four to five orangutans, along with several gibbons, Thomas leaf monkeys, macaques, squirrels and rhinoceros hornbills feeding in a single tree at the same time!
Fauna of Gunung Leuser National Park
Approximately 350 bird species are known to live in the Gunung Leuser National Park, with 36 of the known 50 species endemic to Sundaland (a biodiversity hotspot area comprised of the western half of the Indo-Malayan archipelago) being found in the park. 194 species of reptiles and amphibians and 129 of the 205 species of mammals of Sumatra live in the Gunung Leuser National Park. The forests are thought of as the last stronghold for a number of highly endangered mammals, supporting quite possibly the last remaining viable populations of Sumatran orangutan (Pongo abelii), Sumatran tiger (Panthera tigris sumatrae), Sumatran elephant (Elephas maximus sumatranus) and Sumatran rhinoceros (Dicerorhinus sumatrensis sumatrensis).
The Leuser Ecosystem is the only place on earth where these Critically Endangered species coexist and loss of this habitat will almost undoubtedly result in their extinction in the wild. Besides the orangutan, there are a number of other primate species frequently sighted throughout the Gunung Leuser National Park: the lar gibbon (Hylobates lar), the siamang (Symphalangus syndactylus), the Thomas leaf monkey (Presbytis thomasi), the long-tailed macaque (Macaca fascicularis) and the pig-tailed macaque (M. nemestrina).
One may also be lucky enough to catch a night-time glimpse of the elusive greater slow loris (Nycticebus coucang), an endangered and little known primate relying on the integrity of the Gunung Leuser National Park for its survival. Other fascinating mammals include the Malayan sunbear (Helarctos malayanus) which roams the forest in search of figs and honey, and perhaps the most easily identifiable bird in the park, the hornbill (Family Bucerotidae). Hornbills fly amongst the canopy and can sometimes be seen sharing a tree with orangutans.