Xanthostemon fruticocus is a large tropical tree, also known as the ‘Sierra Madre mangkono’, which is endemic to the Philippines – found nowhere else on Earth. The most recent IUCN assessment of this species lists it as Endangered with a range restricted to only three locations in the remote municipalities of the province of Isabela.
This tree is almost exclusively found in ultramafic forest formations. In its natural habitat it grows very slowly due to the nutrient deficient, heavy-metal rich soils on which it lives. Most ultramafic soils in the Philippines, including those in Dinapigue Isabela have been covered with mining operations which has resulted in the natural habitat of this species being dramatically reduced in the last 100 years.
Despite its slow growth, this tree reproduces very quickly – flowering at a very early age while still a mere short shrub. This early reproduction means that even in the immediate vicinity of mining operations seedlings and small saplings can be found growing in profusion, however these are not safe from destruction. Large, mature individuals of this species are becoming increasingly scarce in the wild.
This is one of the five ironwood (Xanthostemon) species endemic to the Philippines. The valuable wood is considered the hardest of the Philippine timbers – this is how it earned its name as the ironwood tree. The wood is best used in the making of high-quality furniture such as chairs and tables. Despite total bans on logging this species being implemented in the Philippines illegal poaching is still very common. The hardness of the wood gives it its value but also offers some protection against logging however local people continue to cut trees of a smaller diameter, primarily for piles and posts. Being an ultramafic species its survival is always threatened by mining activities. This tree was only published as a new species in 1998 when it was named by the late Filipino botanist, Leonard Co.
Building local knowledge is important for the long-term conservation of this species. Local communities will be equipped with the skills to grow the species in community nurseries. Selling saplings will also provide an additional and sustainable source of income. Working with local authorities, local ordinances for the protection of the species will be prepared. Natural populations will also be increased through reinforcement planting and facilitating natural regeneration. In order to raise awareness and public knowledge of the importance of conserving this and other threatened Philippine tree species, educational material will be created and shared.