Biomass and floristics of a secondary forest in West Kalimantan, Indonesia

Abstract

To understand the biomass and floristics of secondary forests in Borneo better, we established a one-hectare plot on the lower slopes of Gunung Kelam in West Kalimantan, Indonesia. We recorded 683 stems (≥5 cm dbh) representing 50 species, 44 genera and 27 families; the five species with the greatest Importance Value were Artocarpus elasticus (IV＝81.5), Vitex pinnata (40.2), Cryptocarya ferrea (14.2), Polyscias elliptica (12.7) and Gordonia excelsa (10.7); stem dbh distributions differed among species indicating that succession was still occurring. The stand basal area was 29.0 m². We estimated biomass with eight different allometric equations. Four equations (Chave, Hashimoto, Kenzo and Manuri-DGH9) showed very close agreement at around 137 Mg ha^－1 suggesting they were all suitable for mid-aged secondary forest biomass estimation in this region. Despite tree diversity and biomass being lower than nearby primary forest, secondary forests will become increasingly prevalent in the future and this therefore necessitates their increased study and conservation.