The enigma of Yakal disease
Channel: Luntian Farm
Date: 2019-09-20

Shorea astylosa is generally referred to as yakal, a broad and somehow confusing denomination which encompasses diverse species. The tree appears in the Red List by the International Union for Nature Conservation (IUCN), which classified Shorea astylosa as Critically Endangered. 

Since the assessment by IUCN dates back to 1998, the situation might have worsened further. Actually, Shorea astylosa’s geographic range is limited, being endemic to the Philippines, where its habitat has all but disappeared. In fact, yakal trees are a species of the lowland dipterocarp forest, an ecosystem almost lost in the country. 

In an effort towards in situ conservation of a severely threatened species, we introduced yakals in Luntian Farm. Since August 2014 we have planted seventy trees of this species. However, the introduction of Shorea astylosa in the new habitat has showed mixed results. Albeit a few trees grew fairly well, mortality has been very high: out of seventy, 34 died (49%). 

The identification of factors that may impinge on the successful introduction of this species in habitats different from the lowland primary evergreen dipterocarp forest, where yakals used to grow, is essential to establish successful conservation models. We propose here three hypotheses on possible threats that our yakals may have faced in their new habitat, at the foot of the Sierra Madre range, where Luntian Farm is.