Nepenthes Muluensis - Ecology

Ecology

As its name suggests, N. muluensis was originally known only from Mount Mulu. Since its description it has also been found on several other mountains in Sarawak (including Mount Api, Mount Murud, and Bukit Batu Lawi) and one in southwestern Sabah. Nepenthes muluensis has not been recorded from the nearby summit of Mount Benarat, although this is a limestone peak and mostly lies outside the known altitudinal distribution of the species, which is 1700 to 2400 m above sea level.

Nepenthes muluensis grows in nutrient-deficient soils of the upper montane zone. It typically occurs in open areas of mossy forest amongst ridge-top vegetation. On Mount Mulu, the species seems to be restricted to the western ridge and occurs from an elevation of around 1900 m to the summit at 2376 m. The summit vegetation is greatly stunted, rarely exceeding a metre in height. It is dominated by rhododendrons (particularly Rhododendron ericoides), as well as species of the genera Diplycosia and Vaccinium. Nepenthes muluensis is most abundant in summit heath forest, where it forms dense stands with hundreds of white-speckled pitchers suspended over the sympatric shrubs.

On Mount Murud, N. muluensis grows in shady mossy forest. This population produces darker pitchers than the one from Mount Mulu, possibly due to greater exposure to ultraviolet light at higher altitudes. Two true toad species from Mount Murud, Pelophryne linanitensis and Pelophryne murudensis, are sympatric with N. muluensis and may breed in its pitchers.

The conservation status of N. muluensis is listed as Vulnerable on the 2006 IUCN Red List of Threatened Species based on an assessment carried out in 2000. This differs from the assessment made by the World Conservation Monitoring Centre five years earlier, which classified N. muluensis as "endangered". In 1997, Charles Clarke informally classified the species as Endangered based on the IUCN criteria, noting that it is Conservation Dependent if populations in protected areas are taken into account.