DISTRIBUTION AND SILVICULTURAL CHARACTERISTICS OF Dacrydium elatum (Roxb.) Wall IN KON CHU RANG NATURE RESERVE, GIA LAI PROVINCE

Abstract

Dacrydium elatum (Roxb.) Wall, belonging to the family Podocarpaceae, is a rare and valuable timber species. Its wood is fine-textured, straight-grained, aesthetically pleasing, moderately hard, of medium weight, and classified in Group II according to TCVN 12619-2:2019. Field investigations in the Kon Chu Rang Nature Reserve, Gia Lai province, revealed that D. elatum occurs at elevations ranging from 887 to 1.076 m above sea level, within mixed coniferous-broadleaf natural forests. In forest stands where D. elatum is present, the density of the upper tree layer ranges from 480 to 640 trees/ha, with mean diameter at breast height (D1.3) from 22,6 to 27,7 cm and mean total height from 19,3 to 21,1 m. The density of D. elatum itself ranges from 80 to 240 trees/ha, and the species contributes to the dominant group in the stand composition of the upper tree layer. Natural regeneration in these stands reaches densities of 3.840 to 7.040 seedlings/ha. Among the three sample plots, two contained regenerating D. elatum, with densities ranging from 3.280 to 3.680 seedlings/ha. Most individuals regenerated from seeds (82,9 - 95,7%) and were of good quality (72,3 - 82,6%). However, regeneration is mainly concentrated in the height class below 20 cm, with few seedlings showing good growth potential, which may limit the number of mature individuals in the future. Therefore, further research as well as conservation and silvicultural measures to promote regeneration of D. elatum are essential to ensure the establishment of replacement cohorts in the Kon Chu Rang Nature Reserve.