Comparison of Floristic Diversity, Forest Structure and Timber Volume between Primary Forest And Secondary at Sungai Pronggang, Bau, Sarawak

A study was conducted to compare the floristic composition, stand structure, and timber volume between the two forest types. Six 0.04 ha plots were set up in each forest type. The tree species composition, stand density, diameter size were enumerated for every plots. A total of 549 trees were above 5 cm diameter at breast height were enumerated which comprised of 72 families (PF: 38, SF: 34), 122 genera (PF: 69, SF: 53) and 156 species (PF: 95, SF: 61). The most dominant species according to importance value index (IVI) for primary forest was Palaquium majas while Myristica fallax be the most dominant species in secondary forest. The Shannon-Wiener diversity index was 2.67 for the secondary forest plots and 3.24 for the primary forest plots. The timber volume for primary forest is double compared secondary forest. There are major differences between the two forests is in term of floristic diversity while the forest structure shows 50% of similarity statistically. Thirty years of succession is concluded to be insufficient times to for secondary forest to return most of primary forest species and also timber volume. It may take another 30 year for secondary forest to `revert' to primary forest