Assessment of Carbon Stock at Tree Level Using Terrestrial Laser Scanning Vs. Traditional Methods in Tropical Forest, India

Accurate assessment of carbon stock of trees is essential to model carbon dynamics in the forest ecosystem. Estimation of carbon stock at regional level involves successive quantitative modeling at various scales. While developments in airborne and satellite remote sensing has greatly reduced the uncertainty in up scaling of plot level biomass and carbon stock estimates to regional or national estimates. A substantial amount of uncertainty in the system comes when carbon stock of each tree in a plot is estimated from established allometric equations. In this study, 12 trees were destructively measured for their carbon stock value and the same was estimated using terrestrial laser scanning technique, local allometric equations, and global allometric equations. The carbon content estimates from terrestrial laser scanning method (26.01% RMSE relative to mean) were consistently closer to destructive measurements as compared to local allometric equations (42.58%-101.88% RMSE relative to mean) and global allometric equations (38.8%-50.69% RMSE relative to mean). Field measurement of sample wood density and sample carbon content significantly reduced the uncertainty in local allometric equations. The sources of error and applicability of each technique are discussed in this study.