Role and Status of Pioneer Species in the Dynamics of the Mixed Dipterocarp Forests

点击翻译按钮获取中文摘要

Mixed dipterocarp forest is a symbol of wild nature in Asian tropics and is characterized by the great species diversity, tall architecture, and big local variations within the forest. Major professionals in tropical forest researches in the world become aware of the necessity of the long-term ecological research of the forests by establishing the large ecological plots with sizes such as 50 ha, for understanding the forests as they really are. This research project was carried out as a preparation for the long-term and large scale ecological research of the mixed dipterocarp forest in Sarawak through the following activities : 1) the establishment of the 50 ha plot, 2) mapping, forest inventory, and herbarium collection of living trees with DBHs over 1.0 cm, 3) the analysis of species diversity, forest structure, and community dynamics, 4) the comparison of life strategies among pioneer tree species, and 5) synthetic and ecological discussions about the role and status of pioneer species in the dynamics of mixed dipterocarp forest.To demarcate the 50 ha plot with a reliable accuracy, we used an electronic tacheometer. The closure error of the plot was 1.0 m in forest survey. The plot was very complex in topography and included various habitats for plants. The 10 ha forest inventory was done during two year research activities. Pioneer species is short lived and grew faster than climax species, depended their regeneration on canopy gaps, had not effective anti-herbivory substances in leaves, and adopted seed bank strategy using toxic seed coat substances.