The Trees of Pasoh Forest: Stand Structure and Floristic Composition of the 50-ha Forest Research Plot

Abstract

Abstract: Stand structure and floristic composition of the 50-ha Forest Research Plot in Pasoh Forest Reserve (Pasoh FR) are described. Pasoh FR was found to have extremely high tree species diversity. In the 50-ha plot there were 338,924 trees with a total basal area of 1,659 m2, comprising 818 tree species in 295 genera and 81 families. The Euphorbiaceae (85 species) was the most species-rich family. The Dipterocarpaceae dominated the forest with 27% of the basal area, and eight of the top 10 basal-area contributing species. The Fabaceae, Euphorbiaceae and Burseraceae were the next most important large trees in the plot. Shorea had the highest basal area and stem number. Syzygium was the richest genus with 45 species. As with other Asian tropical forests there were many speciose genera in the plot; 11 genera had ≧ 12 species. Floristic composition and stand structure varied across the 50-ha plot in relation to edaphic and topographic variation. Multivariate analyses revealed three main community types: a swamp community in the lowest areas of the plot, a hill community, and an alluvial forest community in mid to lower elevations in the plot. In addition, the alluvial community appears to be divisible into three types based on differences in soil properties. In addition to describing species characteristic of each of these community types, we also describe some of the distinctive life-history and evolutionary characteristics of the Pasoh FR. This chapter provides a basis for future work at Pasoh FR.