Justification
This species is a large tree that naturally thrives in lowland forests in various provinces and localities of Indonesia, Malaysia, and the Philippines. It has an estimated extent of occurrence (EOO) of 3,785,608.444 km² and is known to occur in 42 locations based on currently available information. While the population size is not currently known, the species is facing continuous decline due to habitat-threatening activities such as urbanization, small and large-scale logging, shifting agriculture, and unsustainable farming practices, as well as over-exploitation for its vital purposes.
Despite these threats, it is currently assessed globally as Least Concern (LC) due to its numerous occurrences, wide distribution, and expected abundance. However, to prevent the species from being pushed into a threatened category in the future, its conservation, both in situ and ex situ, is important.
Geographic Range Information
This tree species typically thrives in low-lying forests (Merrill 1923). The species is native to Indonesia, Malaysia, and the Philippines, with known locations in several regions of these countries, including West Sumatra, Jambi, North Sumatra, South Sumatra, Banten, East Kalimantan, and Central Sulawesi in Indonesia; Sabah in Malaysia; and Camarines Sur, Romblon, Leyte, Samar, Sorsogon, Palawan, Dinagat Islands, Antique, Masbate, and Oriental Mindoro in the Philippines. The estimated extent of occurrence (EOO) for this species is 3,785,608.444 km2. According to available herbarium specimens, the species has been observed in 42 different locations throughout the three Southeast Asian countries (GBIF 2023).
Population Information
There is no information on the population size of the species. However, a decline is suspected due to continuous loss of primary forests within its distribution range.
Habitat and Ecology Information
The species is a large tree that occurs in lowland forests of Indonesia, Malaysia, and Philippines (Merrill 1923, GBIF 2023). It is scattered in rainforests, often on calcareous soil or on limestone rocks; at elevations from 150 - 900 m (Useful tropical Plants 2014). Based on collected herbarium specimens the species is a slender erect tree that grows to about 18-20 m tall (Elmer 1911, GBIF 2023). Its trunk was observed to be 12-15m high. Its wood is hard and whitish, suitable for building houses (Blume 1849). Its habitat and ecology is insufficiently known and there is no information on its phenology as well. Thus, further research, exploration, and inventory are needed to further understand and assess the species.
Threats Information
It is primarily threatened by land conversion and habitat degradation brought by commodity-driven deforestation, shifting cultivation, urbanization, and forestry related activities. A significant loss of natural forests was reported in its localities based on the analyaed data from Global Forest Watch (2023). As of 2020, loss of natural forest in Indonesia was recorded as follows: 38,800 ha in East Kalimantan, 7,930 ha in West Sumatra, 6,280 ha in North Sumatra, 7,240 ha in South Sumatra, 10, 700 ha in Central Sulawesi, 24,100 ha in Jambi, and 57.4 ha in Banten. Lastly, the forest cover loss in the Philippines is as follows: 2,880 ha in Antique, 13,600 ha in Camarines Sur, 2,700 ha in Dinagat Island, 36,700 ha in Leyte, 6,880 ha in Masbate, 21,500 ha in Oriental Mindoro, 163,000 ha in Palawan, 5,290 ha in Romblon, 35,900 ha in Samar, and 4,570 ha in Sorsogon. Interventions and conservation actions are highly recommended to prevent further tree cover loss and population decline.
Use and Trade Information
The species is harvested from the wild for mainly local use as a medicine and possible as a source of wood. The seeds of this genus might be one of the several species that are harvested for commercial use of their seed as a source of chaulmoogri oil (most commonly harvested from Hydnocarpus kurzii). Although there is no specific information for this species, the seeds of many members of this genus contain cyanogenetic glycosides. In very small quantities this has been used medicinally, having been shown to stimulate respiration and improve digestion, it is also claimed to be of benefit in the treatment of cancer. In excess, however, it can cause respiratory failure and even death. Also, the seeds of this species contain a fatty substance, which is extracted and used topically as a treatment against skin-diseases. The white wood is very hard, but apparently not used. When it attains suitable dimensions, the wood of species in this genus is often used locally for house building (poles), temporary heavy construction, posts, fences, interior finishing, panelling and door and window frames (Sahoo et al. 2014, Useful Tropical Plants 2022).
Conservation Actions Information
The population of the species is protected in situ because of its presence in declared protected areas (PAs). In Indonesia, these are Kerinci Seblat National Park and Ujung Kulon National Park. In the Philippines the species occurs in protected areas namely, Mts. Iglit-Baco Natural Park, Bulusan Volcano Natural Park, Dalanas River Watershed Forest Reserve, Samar Island Natural Park, Palawan Flora, Fauna and Watershed Forest Reserve (Parcel 1), Mt. Mantalingahan Protected Landscape. Although these PAs are supported by law, conservation of the species' population is not guaranteed due to several threats which may cause rapid population decline. In addition, the species is not listed in the Philippine Red List and therefore not protected by law against illegal collection or extraction from Philippine wild populations (DENR-BMB 2017). Thus, species-specific conservation programmes, including cultivation in botanic gardens for ex situ conservation are recommended to ensure its continuous survival.