Tree stand floristic dynamics in secondary forests of different ages in Sarawak, Malaysia

Abstract

Karyati, Ipor IB, Jusoh I, Wasli ME. 2018. Tree stand floristic dynamics in secondary forests of different ages in Sarawak, Malaysia. Biodiversitas 19: 717-723. Succession is a series sequential processes of the development of floristic community which involves changes in community structure, species composition and diversity over time. The information on tree stand floristic dynamics of various stages of succession in secondary forests in Malaysia is currently lacking. This study was conducted to determine tree stand structure, floristic composition, and species diversity in various stages of secondary forest development in the study areas. A total of 997, 1,842, and 834 tree stems with diameter at breast height (DBH) of > 5 cm were recorded in one-hectare-plots of 5, 10, and 20 year old secondary forests, respectively. The ten most common species in 5 and 10 year old of secondary forests consisted mostly of light demanding species. In the 20 year old secondary forest, these species did not exist. Macaranga gigantea was the most dominant tree species in the 5 and 10 year old secondary forests in terms of basal area and volume per hectare. The most common species, based on density, basal area, volume, and Importance Value Index (IVi), in the 20 year old secondary forest was Adinandra dumosa. The diversity and richness indices of the 10 year old secondary forest were the highest among all study sites.

The role of tropical abandoned land relative to ecological and economic aspects

“…were also common based on the Summed Dominance Ratio (SDR) in 3 and 5 years of fallow lands in Sarawak (Karyati et al, 2013). This is in line with the findings of Karyati et al (2018) that trees species in lands abandoned for 5 and 10 years were dominated by Macaranga spp.…”

“…The study showed the floristic structure, composition, and diversity were related to the existence and importance of the abandoned land dominated by fast-growing species. Moreover, the species of tree on the site had 'intermediate diversity' (H'), 'low dominance' (Ds), and 'high evenness' (J') and the same was found for seedling-sapling plants with DBH< 5 cm and tree plants with DBH>5 cm in 3, 5, 10, and 20 years after the lands have been fallowed (Karyati et al, 2013;Karyati et al, 2018). This, therefore, means abandoned land has important ecological roles.…”

“…Macaranga gigantea, Vitex pubescens, and Dillenia suffruticosa were three dominant species in terms of density, basal area and volume per hectare in the 5 and 10 year old after abandoned lands. In addition, Macaranga hypoleuca and Macaranga caladifolia were also common in the 10 year old of abandoned land, while Macaranga trichocarpa in the 5 year old of abandoned land (Karyati et al, 2018).…”

Allometric equations to estimate the above-ground biomass of trees in the tropical secondary forests of different ages

“…The study was carried out in 5-, 10-, and 20-year-old secondary forest in Sarawak, East Malaysia, respectively located in 01°04'43.3''N 110°59'02.0''E, 01°03'55.9''N 110°55'51.4''E, and 01°03'59.3''N 110°53'34.4''E. The previous study on composition and diversity of trees (Karyati et al 2018) as well as their soil properties (Karyati et al 2014) has been done in these study sites. The forest type in the study plots was lowland mixed dipterocarp forest with heath forest (kerangas) (Kendawang et al 2007).…”

“…A total number of 30 trees (DBH of > 5 cm) were selected in each age class (5, 10, and 20 years old) of secondary forests, with consideration of the species and DBH, not considering individuals with damaged crowns or broken trunks. Almost 90% of the selected trees were categorized as the dominant species in terms of density and Importance Value Index (IVi) in each study site as reported by Karyati et al (2018), while few selected trees represented the rare species. The DBH of selected trees proportionally represented each DBH class in each study site.…”