Biomass, Carbon Stock and Carbon Dioxide Removal Across Different Girth Classes of Eucalyptus species in Punjab: Implication for Eucalyptus Plantations

A total of 17 girth classes were considered to estimate the volume, biomass, carbon and carbon dioxide removal in Eucalyptus plantations in Punjab. All the studied parameters showed increment from lower girth classes towards higher girth classes. Mean tree height varied from 10.97 (25–30 cm) to 25.33 m (106–110 cm) and tree volume from 0.03 (Gl) to 0.67 m³ (G₁₇). Dry biomass showed significant variation among different girth classes and it ranged from 1.5 to 36.72 kg in leaf and twig parts, from 2.81 to 86.48 kg in branch parts, from 22.4 to 636.54 kg in the logs in lower to higher girth classes, respectively. There was a strong positive association between girth class and tree biomass (R²= 0.971). Total carbon sequestration potential per tree ranged between 13.62 (G,) and 387.47 kg (G₁₇). Carbon dioxide content in a tree ranged from 49.9 to 1422.02 kg, respectively in lower girth class (25–30 cm) to higher girth class (106–110 cm). There was a strong positive trend between girth classes and carbon/CO₂ content. This study may be useful for estimation of biomass and carbon stock of trees having attained girth ranging from 25 to 110 cm irrespective of age and the site conditions. It will also be useful to estimate the optimum age at which trees should be felled to harvest the maximum carbon.