Above Ground Productivity and Carbon Sequestration Potential of Eucalyptus Hybrid in Punjab

Eucalyptus hybrid has been planted in Punjab in linear strips along roads and canals, in small forest blocks and on farmer's fields in association with agricultural crops under agroforestry systems. The number of Eucalyptus and Poplar trees growing outside forests exceeds 28 million. Such tree planting practices have expanded the opportunity to increase wood production and slow down CO₂ concentrations in the atmosphere. Data on diameter at breast height, tree height, fresh weight of different tree components (timber, small wood, fuel wood, leaves) of 95 Eucalyptus hybrid trees with diameter at breast height ranging from 7.1- 56.3 cm and height from 10.0-42.0 m across Punjab state in seven forest divisions were collected to develop prediction equations for weight (fresh and air dry) of different tree components and estimate carbon stock and amount of CO₂ removed from atmosphere. The logarithmic model Y= b₁ D^b2 H^b3 with two variables, diameter and tree height, was found to be the best fit with a high R² (0.99, P<0.01). Based on sampled trees, Eucalyptus hybrid grown under Punjab's climatic conditions attained an average air dry timber density of 550 ± 28 kg/m³. A conversion factor of 0.524 ± 0.026 to convert fresh weight to air dry weight of small wood and fuelwood was also estimated. From the best-fit equations, user-friendly tables for above ground biomass, carbon stock and amount of CO₂ removed were also developed.