Burni Bias and Pepanyi

A(i)Site contains one or more globally threatened species

Burni Bias and Pepanyi are important habitats for globally threatened plants, with two Critically Endangered, two Vulnerable and one Endangered species recorded at the site. There are also several species endemic to the North Gayo region which have not been accessed for their conservation status, but are likely to be threatened. The site also holds populations of North Gayo endemic slipper orchids Paphiopedilum bungebelangi and Paphiopedilum lunatum, which are highly susceptible to extinction due to their economic value as commercial ornamental plants. Other information like culturally important plants have not been studied in this region, but the forest itself is a site of traditional hunting area.

Burni Bias and Pepanyi are inactive volcanoes covered by submontane to montane forests in the northern part of the Gayo Plateau, Aceh Provinces, Sumatra. The two summits are Burni Bias (2020 m asl) and Burni Pepanyi (2025 m asl). The landscape of both summits has an elevation range from 1300 to 2025 m asl. The area is impacted by the rapid conversion for agricultural and associated activities (Robiansyah et al. 2023, Mustaqim et al. 2024a) and is not under formal protection from the Indonesian government. The area is traditionally owned by Gayonese and routine traditional hunting depends on the existence of forests. With two montane bogs occurring in this area (e.g. Mustaqim et al. 2024b), the forests are important in providing water for the surrounding ecosystems including consumed water.

This site contains important populations of threatened species which are endemic to the northern Gayo highlands, i.e. Magnolia banghamii (CR), Nepenthes lavicola (CR), and Horsfieldia atjehensis (VU). Castanopsis argentea (EN) and Pinus merkusii (VU) are also recorded at the site. There are significant populations of northern Gayo endemic species that are potentially threatened, including Rhododendron frey-wysslingii and Impatiens bungeilang. Several range-restricted orchid species are present at the site, including Gayo endemics Dendrobium gayoense, Paphiopedilum bungebelangi, and Paphiopedilum lunatum, and Sumatran endemic Coelogyne ovata. Important habitats in this site include the submontane to montane forests and the regionally threatened montane bogs which are usually rich in orchids.

Burni Bias and Pepanyi forests belong to the Sumatran montane forest ecoregions (Olson et al. 2012), one area with the highest biodiversity in the world. For vascular plants, Barthlott et al. (2005) scored 8 to 9 out of 10 for diversity zone, which means that there are 3000 to 5000 plant species per 10,000 km square. Two types of habitats are present namely the montane forests and montane bogs. The forests are marked by the frequent presence of the oak family, including the threatened Castanopsis argentea. The montane bogs vegetation consists of Ericaceous-dominated shrubbery and is inhabited by large amount of the highly threatened Nepenthes lavicola. Forests below 1800 m asl have been changed to agricultural landscapes and settlements. Burni Bias and Burni Pepanyi are two old inactive volcanoes and the rock formations belong to young volcanic deposits alongside the more popular Burni Geureudong and, the active volcanoes, Burni Telong in the north (Survey of India Offices 1944).

The two summits are highly threatened by ongoing habitat conversion for agricultural activities, settlements, roads, and tourism (Gayo et al. 2018, Robiansyah et al. 2023, Mustaqim et al. 2024). The forest loss on both summits is ongoing, leaving forests as remnants on extreme sites like the steep slopes of cliffs. Areas shown by Global Forest Watch data as forest are in reality coffee plantations with the non-native shade tree species such as avocado or Leucaena leucocephala. Also, the map shows visible forest losses in the higher elevations (Global Forest Watch 2025). The forest fragments in Tensaren, near the summit of Burni Pepanyi, is a habitat of the endemic and globally Vulnerable (VU) Thomas’ langur (Presbytis thomasi) (2024, pers. obs.) and Malayan sun bear (Helartcos malayanus, VU) (Scotson et al. 2017).

In recent times, there seems to have been no direct harvesting of wood for commercial timber. Only small trees are chopped for use as agricultural tools. The forests are important for water catchment areas, used for irrigation and drinking water by people nearby, and also act as green corridors for the vast amounts of nearby coffee plantations. The drinking water comes from a small montane bog in Burni Bias.

Wendy Mustaqim, Universitas Samudra, Indonesia

Enggal Primananda, National Research and Innovation Agency, Indonesia

Iyan Robiansyah, National Research and Innovation Agency, Indonesia

Laura Jennings, Royal Botanic Garden Kew

Liam Trethowan, Royal Botanic Gardens, Kew

Date of first assessment: 27th Feb 2025