Distribution and conservation implications of limestone plant species in Felda Chiku Limestone Flora, Kelantan, Malaysia

Nationally, the limestone flora is one of the most threatened ecosystems of Peninsular Malaysia. Distribution of the species is a critical factor hampering the conservation of limestone flora. Threatened by the largest cement clinker factory in Southeast Asia, to consume the two largest hills in Federal Land Development Association (FELDA) Chiku oil palm plantation, Kelantan, an intensive survey was initiated to document and provide a permanent record of species richness within the four FELDA Chiku limestone hills and the adjacent one in Relai Forest Reserve. The checklist recorded 266 species of vascular plants in 166 genera and 62 families, of which 27 species are endemic to Peninsular Malaysia, 6 endemic to the state of Kelantan and 3 were site endemics with two new species. The Chiku flora comprised only a fraction (22%) of the total limestone flora of the Peninsula, i.e. 1,216 species. No single hill had more than 60% of the 266 species and each of the five hills had a different combination of species. None of the site endemics were found on all five hills, which means no single hill will conserve all the species. Furthermore, 84 species found on the two hills designated for quarrying were not found on the other three hills, contradicting the view that protecting another hill of similar size would protect the entire Chiku limestone flora or that adjacent hills will harbour the same biodiversity. Clearly a network of hills is needed to adequately conserve limestone biodiversity. Hill size, as judged by basal area, did not predict species richness, instead diversity of microhabitats was the most important parameter.