IMPACT OF SELECTIVE LOGGING ON THE DYNAMICS OF A LOW ELEVATION DENSE MOIST EVERGREEN FOREST IN THE WESTERN GHATS (SOUTH-INDIA)

Within the framework of a programme on the functioning of dense moist evergreen forests of the Western Ghats, the French Institute of Pondic herry, in collaboration with the Karnataka Forest Department, installe d permanent plots to monitor the dynamics of a low elevation forest. T he preliminary results of the comparison of the demographic processes in two compartments are presented: one compartment had never been harv ested, while the other was selectively felled in 1979-1980. They are c ompared in terms of species composition, recruitment, mortality and in dividual growth, in order to describe the natural forest dynamics and evaluate the impact of selective felling. In both compartments, the mo rtality rate, around 0.9% yr(-1), is lower than in other tropical mois t evergreen forests, while the average diameter increment, at 2.1 (unl ogged stand) and 2.9 mm yr(-1) (logged stand), is higher. The impact o f selective felling, 10 to 15 years after the harvest, is mainly notic eable: (i) on mortality of trees with dbh > 40 cm belonging to lower c anopy and intermediate stratum species which died about four times mor e in the logged compartment; and (ii) on diameter increment of emergen t and upper canopy tree species whose growth is still stimulated by ab out 50%. Despite the general trend of a reduction in the difference be tween the density and the basal area of the two compartments, medium-t erm modification of the demographic processes among the various struct ural ensembles in the logged compartment, indicates that selective fel ling may not be sustainable in the long-term without consequences on t he forest structure and composition. (C) 1998 Elsevier Science B.V.