Growth, Stem Volume and Plant Succession in Pinus kesiya Plantations, Northern Watershed, Chiang Mai Province

Abstract

Studies on the growth, stem volume and plant succession in 14-34 year-old pine plantations (21 age classes) were carried out at Boakaew watershed station, Chiang Mai province. Average growth increments of Pinus kesiya in these plantations were determined as: average height, 0.82 m/yr; average diameter at breast height, 1.28 cm/yr; and average volume, 6.23 m³/ha/yr. There were 17-72 species of successional broadleaved tree species with a density of 540-2,688 trees/ha, and a volume increment of 2.63 m³/ha/yr. The density of Pinus kesiya varied between 75 and 429 trees/ha whereas other species had 131-2,331 trees/ha. The Shannon-Wiener index of species diversity in the plantations varied among plantations with a range of 1.57-4.65. The successional broadleaved tree species in the pine plantations mainly belonged to the families Fagaceae, Euphorbiaceae, Juglandaceae, Lauraceae, and Myrtaceae. Successional stages will result in the plantations developing into natural lower montane evergreen forest.

Keywords:  Northern watershed, pine growth, stem volume, succession, pine plantation