Canopy Structure of a Logged-over Forest: Thirty Years After Logging

Phytosociological studies were carried out in Compartment 128, Pasoh Forest Reserve, Negeri Sembilan, in order to assess the canopy structure and vegetation composition of the logged-over dipterocarp forest, thirty years after logging. A total of ten plots, each with the size of 60 x 40 m, were established to assess the vegetation composition, species dominance and stand structure for the compartment. Studies showed that the stand can be categorized as a Syzygium - Canarium stand. Meanwhile, the species composition of the study area can be differentiated into two communities, namely, Dialium kunstleri - Baccaurea sumatrana community and Hopea odorata - Palaquium rostratum community, and these communities can be further differentiated into four sub-communities. The vegetation of the compartment recorded the average of 12.5% canopy layer recovery of the emergent layer (ST), and 40%, 41.5%, 25.5%, and 17.5% for the dominant and co-dominant (Tl), understorey (T2), shrub (S) and herb (H) layers, respectively. The family with the most representative was Dipterocarpaceae with twelve species representing three genera, followed by Leguminosae.INTRODUCTIONPeninsular Malaysia is blessed with a unique tropical forest ecosystem. The forest, which is a highly valuable economic resource, has been systematically managed by the Forestry Department Peninsular Malaysia since 1901. For instance, the lowland and hill dipterocarp forests have been managed under the Malayan Uniform System (MUS) and Selective Management System (SMS), respectively. Even though the forest is being harvested annually, harvesting is carried out according to the strict guidelines of MUS and SMS.The MUS was first formulated into the approved system at the 1949 Conference of Malayan State Forest Officers (Wyatt-Smith, 1995), and was first implemented in 1955 (Yusuf et al., 1986). According to the guideline of the system, all mature trees of commercial species above 45 cm in DBH are to be removed in a single harvesting.Naturally, the forest will recover after harvesting, and in the case of the MUS, the forest is expected to recover within 50 to 55 years (Wyatt-Smith, 1995). However the rate