Importance Value Index and Assessment of Carbon Stocks in Western Bhutan Himalaya (Thimphu)

Abstract

This study assessed the importance value index to determine the importance of each tree species in relation to carbon stocks. The assessment was based on woody stem ≥10 cm diameter at breast height (DBH) and tree height.  Biomass was estimated using volumetric equations and carbon stock by multiplying constant factor 0.5 to the biomass. The results showed biomass and carbon stock varied in different territorial forest ranges. Maximum biomass recorded from Thimphu forest range with 62.306 Mgha-1 followed by Khasadrapchu forest range 55.503 Mgha-1, Chamgang forest range 41.556 Mgha-1 and Gidakom forest range 32.133 Mgha-1 with carbon stock of 31.153 MgCha-1, 27.752 MgCha-1, 20.778 MgCh-1 and 16.066 MgCha-1 respectively. Total respective biomass and carbon stock of Thimphu conifer forest from sampling plots were 191.501 Mgha-1and 95.740 MgCha-1. All forests range had a similar tree size with dominant DBH class at ≥10-40 cm contributing greater biomass and carbon stock. Carbon storage potential in plant biomass using non-destructive method was never conducted before in the present study area. To reduce research gaps, present study used non-destructive methods and concludes that Thimphu conifer forest has enormous potential to accumulate biomass and carbon stock.