Estimation of wood volume, carbon stock and rotation age in subtropical pine forests of malakand, khyber pakhtunkhwa

This study was conducted in subtropical pine forests of Malakand, situated at an elevation of 762 to 1165 m asl (34°34 ́ North-latitude & 71º54 ́ East-longitudes) in Khyber Pakhtunkhwa. The study was aimed at estimating wood volume and carbon stock in the target area and determining a proper rotation age for Sub-tropical pine (Pinus roxburghii) forests. Using a simple random sampling technique, a total of 20 sample plots (with plot size of 50m×50m) were laid out in the forest area. Data was recorded for tree Diameter at breast Height (DBH), tree height, radial increment in the last 10 years, tree density and tree age for each age class. The results indicated that the tree DBH and height shows a logistic type of relation with stand age, i.e., first increase slowly then at faster rate and later-on the tree growths decline or level-off at higher ages. The average stand basal area and stand volume were 11.8 m2/ha and 85.04 m3/ha respectively. Tree density was 117 trees/ha, above and below ground tree biomass were 54.05 and 14.05 t/ha respectively. The aboveground carbon and belowground carbon were estimated as 27.02 and 7.03 t/ha respectively and the total tree carbon stock was determined as 34.05 t/ha. The proper economic rotation age for Subtropical pine forests was suggested as 90 years to get relatively maximum wood production. The study concluded that Subtropical pine forests have high potential for wood production and carbon sequestration if managed properly. (author)