DECLINE OF TEAK YIELD IN NORTHERN THAILAND - EFFECTS OF SELECTIVE LOGGING ON FOREST STRUCTURE

Harvest of Tectona grandis in N Thailand in 1985 was only 10% that in 1971. Previous removal of large trees during selective logging may have been a reason for present low yields of teak. In a selectively logged mixed deciduous forest, most of the remaining teak was concentrated in diameter size classes <50 cm. In contrast, most of the teak stumps were larger than this diameter. The large trees had been removed by logging. Reduction of teak production in Thailand to the point where sustainable, profitable yield is no longer possible may have resulted from over-intensive harvest of large trees. -from Authors