STAND STRUCTURE AND ABOVE-GROUND BIOMASS OF NATURAL FORESTS IN LA NGA PROTECTION FOREST MANAGEMENT BOARD, LAM DONG PROVINCE

Abstract

Research on the structure and biomass of natural forests provides an essential scientific basis for assessing ecological functions and supporting sustainable forest management. This study utilized data from 102 sample plots (500 m²) and 408 subplots (25 m²) to evaluate the stand structure and above - ground biomass (AGB) of evergreen broadleaf forests and woody - bamboo mixed forests in La Nga Protection Forest Management Board, Lam Dong province. Results showed that the mean stem density of the overstorey varied across forest types, ranging from 522 trees/ha in woody - bamboo mixed forests (HG) to 836 trees/ha in rich forests (TXG). The number of dominant species (IVi > 5%) varied between 3 and 7 across the different forest types. Tree diameter and height distributions in HG were well - fitted to the Meyer function and Weibull distribution, respectively. Regeneration density ranged from 3,740 trees/ha in TXG to 4,324 trees/ha in poor forests (TXN). However, regeneration quality was generally moderate, with promising regeneration accounting for less than 35% of the total density. AGB differed significantly among forest types, with the highest value observed in TXG  (201.0 ton/ ha) and the lowest in TXN (75.1 ton/ha). The study highlights that conserving and maintaining large - diameter trees is a key strategy for enhancing biomass accumulation and carbon storage, thereby supporting sustainable forest management and restoration.