Carbon stock potential in Pinus roxburghii forests of Indian Himalayan regions

Chir pine (Pinus roxburghii) is the most important tree species used for afforestation programs in the Himalayan regions. In the present study, fourteen forest stands were selected in four different altitudes, i.e., < 1000, 1001-1400, 1401-1800, and > 1801 masl in Garhwal Himalayan of Uttarakhand, India, to assess carbon stock potential of the forest. The study was conducted during 2013-2015. Among the study sites, the maximum tree density (575 +/- 90.14 ind. ha(-1)) was reported in New Tehri (altitude: > 1801 masl) and minimum (135 +/- 5.00 ind. ha(-1)) in Daddi (altitude: 1001-1400 masl). The highest (96 +/- 18.36 t ha(-1)) above-ground carbon stock was estimated in Kandikhal where bole, branch, and foliage contribute 89.93 +/- 19.47, 5.17 +/- 1.04 and 0.90 +/- 0.14 t ha(-1), respectively, while lowest (26.68 +/- 9.48 t ha(-1)) was in Gumkhal, and contribution from the same component was found as 20.72 +/- 7.84, 4.50 +/- 1.58, and 1.47 +/- 0.11 t ha(-1), respectively. Further, highest value of below-ground carbon was in Kandikhal (28.58 +/- 4.81 t ha(-1)) with an altitude range between 1001 and 1400 masl and the lowest in Gumkhal (9.19 +/- 2.87 t ha(-1)) between 1401 and 1800 masl. Besides, litter production was found higher in the summer season followed by winter and rainy seasons. The study concluded that the density, height, basal area, and volume of Pinus roxburgii varied with altitude, but it was not directional. However, growth patterns and tree density were the key factors in estimating total carbon stocks and further to know the behavior of carbon dynamics (source/sink). Litter production had an inverse relation with altitude; however, increase in litter biomass at > 1801 masl was observed due to new plantations of pine. This study will be highly helpful to the forester and policy-makers in planning carbon mitigation strategies (e.g., catchment area treatment, afforestation activities) at regional and global scales.

Automated summary

This study assessed the carbon stock potential of chir pine forests in different altitudes of the Himalayan region, highlighting tree density and growth patterns as key factors influencing total carbon stocks; litter production was found to have an inverse relation with altitude.