The Ecology of Nepenthes in Sintang Regency, West Kalimantan, Indonesia

This study aims to describe and analyze the diversity, reproductive organs, and relationships of Nepenthes with environmental factors in Sintang Regency. The study procedures were carried out at 41 sites in several habitat types, including post-mining site, kerangas forest, secondary kerangas, swamp vegetation, peat swamp forest, tropical rain forest, and secondary tropical rain forest. The results showed that there were 10 Nepenthes species in Sintang Regency, namely N. ampullaria, N. bicalcarata, N. gracilis, N. mirabilis, N. rafflesiana, N. x kuchingensis, N. x trichocarpa, N. x hookeriana, N. x cantleyi, and N. x neglecta. In addition, kerangas forest had the highest number of species (9 species), with the highest density being reported in post-mining site (D=6.008 Ind/Ha). N. gracilis and N. mirabilis had the highest importance value index in almost all habitats, while the highest diversity index was found in kerangas forest (H’=1,50). The post-mining sites had the highest number of reproductive organs consisting of inflorescences and infructescence compared to other habitats. Based on correlation analysis, there were significant correlations between diversity index with pH, soil organic matter, and light intensity. The most suitable habitat for Nepenthes in the non-conservation area of Sintang Regency was believed to be kerangas forest. Therefore, it was recommended that conservation action be prioritized in this area.