Pittosporum peridoticola (Pittosporaceae), a new ultramafic obligate species restricted to Kinabalu Park (Sabah, Malaysia).

John B Sugau,Antony Van Der Ent

doi:10.1186/s40529-016-0119-9

Abstract

BackgroundKinabalu Park, in Sabah (Malaysia) on Borneo Island, is renowned for the exceptionally high plant diversity it protects, with at least 5000 plant species enumerated to date. Discoveries of plant novelties continue to be made in Sabah, especially on isolated ultramafic outcrops, including in the genus Pittosporum (Pittosporaceae) with P. linearifolium from Bukit Hampuan on the southern border of the Park, and P. silamense from Bukit Silam in Eastern Sabah, both narrow endemics restricted to ultramafic soils.ResultsA distinctive new species of Pittosporum (P. peridoticola J.B.Sugau and Ent, sp. nov.) was discovered on Mount Tambuyukon in the north of Kinabalu Park during ecological fieldwork. The diagnostic morphological characters of this taxon are discussed and information about the habitat in which it grows is provided. The soil chemistry in the rooting zone of P. peridoticola has high magnesium to calcium quotients, high extractable nickel and manganese concentrations, but low potassium and phosphorus concentrations, as is typical for ultramafic soils. Analysis of foliar samples of various Pittosporum-species originating from ultramafic and non-ultramafic soils showed a comparable foliar elemental stoichiometry that is suggestive of ‘Excluder-type’ ecophysiology.Conclusion Pittosporum peridoticola is an ultramafic obligate species restricted to Kinabalu Park with only two known populations within the boundaries of the protected area. It is vulnerable to any future stochastic landscape disturbance events, such as forest fires or severe droughts, and therefore its conservation status is ‘Near Threatened’.

Highlights

Kinabalu Park, in Sabah (Malaysia) on Borneo Island, is renowned for the exceptionally high plant diversity it protects, with at least 5000 plant species enumerated to date
Kinabalu Park, in the northwestern part of the Malaysian state of Sabah, is renowned for the exceptionally high plant diversity it harbours, with over 5000 plant species enumerated from an area less than 1200 km2 (Beaman 2005; Van der Ent et al 2015a)
Distribution and ecology of the genus Pittosporum in Sabah The family Pittosporaceae consists of nine genera, of which the genus Pittosporum is the sole representative in Sabah (Malaysia, on the island of Borneo)

Summary

Introduction

Kinabalu Park, in Sabah (Malaysia) on Borneo Island, is renowned for the exceptionally high plant diversity it protects, with at least 5000 plant species enumerated to date. Discoveries of plant novelties continue to be made in Sabah, especially on isolated ultramafic outcrops, including in the genus Pittosporum (Pittosporaceae) with P. linearifolium from Bukit Hampuan on the southern border of the Park, and P. silamense from Bukit Silam in Eastern Sabah, both narrow endemics restricted to ultramafic soils. Kinabalu Park, in the northwestern part of the Malaysian state of Sabah (on Borneo Island), is renowned for the exceptionally high plant diversity it harbours, with over 5000 plant species enumerated from an area less than 1200 km (Beaman 2005; Van der Ent et al 2015a). In Kinabalu Park, ultramafic soils are known for high levels of species-richness and (local) endemism (Beaman and Beaman 1990).

Methods

Results

Conclusion