Nepenthes Villosa - Ecology

Ecology

Nepenthes villosa is endemic to the upper slopes of Mount Kinabalu and neighbouring Mount Tambuyukon in Sabah, Borneo. It generally grows at 2300–3240 m above sea level, the highest altitude of all Bornean Nepenthes species; only N. lamii and N. sp. Papua from New Guinea are found at greater elevations. On Mount Kinabalu, N. villosa is common along the Mesilau Trail (between Pondok Magnolia and the meeting point with the old summit trail) and almost all the way up to the Laban Rata rest house; a particularly large population has been reported at around 3047 m. On Mount Tambuyukon, an altitudinal inversion has been noted, whereby N. villosa is more common at much lower elevations of 1600–1900 m, being replaced by N. rajah towards the summit. The exposed, uppermost slopes of Mount Tambuyukon can become very hot during the day and this might explain the inability of N. villosa to colonise them.

Nepenthes villosa often grows in mossy forest and sub-alpine forest dominated by species of the genera Dacrydium and Leptospermum, particularly Leptospermum recurvum. It has also been recorded growing among shrubs, grass, and boulders in open areas. Here the soil may become relatively dry, although relative humidity is usually close to 100% as the slopes are often enveloped in clouds. Like many Nepenthes from the Mount Kinabalu area, it is endemic to ultramafic soils.

The conservation status of N. villosa is listed as Vulnerable on the 2006 IUCN Red List of Threatened Species. Although many plants grow along Mount Kinabalu's summit trail and are easily accessible to climbers, all known populations of the species grow within Kinabalu National Park and so their collection is illegal. In 1997, Charles Clarke suggested a revised assessment of Conservation Dependent based on this. Clarke writes that N. villosa "has a secure future", although he adds that climbers have had a significant impact on populations of the species growing along the summit trail, with the number of plants having declined in recent years. A 2002 study found 1180 individual N. villosa growing in 11 plots, each measuring 0.01 hectares, at elevations of between 2610 m and 2970 m on Mount Kinabalu. This number constituted 94% of the pitcher plants recorded from the plots, the rest being N. × kinabaluensis.