11. Height growth, diameter increment and age relationship response to sustainable volume of subtropical Chir pine (Pinus roxburghii) forest of Karaker Barikot forest
Abstract
This study was conducted in the Karaker Barikot forest of district Swat Pakistan to measure the relation of average tree height, diameter increment and age of Pinus roxburghii to the sustainable volume production. Total forest area was 724 hectares. Systematic sampling intensity 2.5% was used for the study area. Data was collected from 119 plots (1 plot= 0.1 hectare. The tree height (m), diameter increment (cm) and age (years) were measured using Spegial Relascope, Increment borer, and Diameter tape. The maximum tree height was estimated 23 m of 70 year age, and minimum 8.5 m of 13 year age. The maximum diameter increment was found (5.4 cm for lower diameter classes (12 cm) and minimum for 2.2 cm of higher diameter classes (64 cm). The total average number of trees and volume were found 1314, 1104 m³ respectively. The R² values were (.37, .98, .99 of tree height, increment and age with diameter classes (12-64 cm) respectively. The R² value (.988) was found significant for age and increment. It was concluded that there was significant relationship to the average age and height of Pinus roxburghii to the volume production. It was further concluded that the maximum growth increment significantly put the forest on the way to sustainability.
Keywords: Diameter increment; Increment borer; Spegial relascope; Sustainable
