MAINTENANCE OF GENETIC DIVERSITY IN PARKIA SPECIOSA IN LOGGED-OVER FORESTS

Abstract

This study examined the effects of a single logging event (taken place more than 40 years ago) on the genetic diversity of Parkia speciosa in a lowland dipterocarp forest. Random amplified polymorphic DNA (RAPD) markers were used to estimate the genetic diversity parameters, namely, Shannon's diversity index, mean number of alleles per locus, effective number of alleles per locus, Nei's gene diversity and percentage of polymorphic loci. A total of 27 to 33 adult P. speciosa trees from three adjacent forest management units in Pasoh Forest Reserve, i.e., the Unlogged Stand (control site), Regenerated Stand 1 (logged in 1951) and Regenerated Stand 2 (logged in 1955) were analysed. RAPD analyses using seven 10-mer arbitrary primers yielded a total of 51 consistent loci. The t-tests showed that the overall genetic diversity measures of P. speciosa from
the two regenerated stands were not significantly different from the control site. With the assumption that these three "subpopulations" were genetically identical before logging, this may indicate that a single logging event under the Malayan Uniform System (MUS) of harvesting practice did not cause genetic erosion in P. speciosa.