Biomass production and carbon sequestration of Eucalyptus tereticornis plantation in reclaimed sodic soils of north-west India

Eucalyptus tereticornis is most preferred, adopted by farmers in Haryana as agroforestry species due to regular and assured income from expanding market of wood. Accurate and reliable predictive models are important tool to estimate biomass and C-stocks non-destructively in view of emerging carbon credit market mechanism. Allometric models (non-linear) were developed to estimate biomass and biomass carbon in different tree components. Adjusted R-2 for fitted functions varied from 0.911 to 0.995 for different components. Above ground biomass (AGB) = 0.493 X (DBH)(1.)(81) with adjusted R-2 value of 0.992 and below ground biomass (BGB) = 0.130 x (DBH)(1.)(89) with adjusted R-2 value of 0.987 were found best fit equations. Using models, the estimated total dry biomass was 225 mg/ha with biomass accumulation in decreasing order of bole>roots>twigs and leaves>fuelwood (branches). Mean C-concentration in different tree components varied from 43-46%. C-stocks ranged from 2.30 in fuel wood to 69.8 mg/ha in bole. Total C-stocks (AGB carbon+BGB carbon+soil carbon) were estimated to 122.6 mg/ha with CO2 mitigation potential of 369.2 mg/ha in 6 year old E. tereticornis plantation. Carbon sequestration rate in plantations yielded 12.9 mg C/ ha/year. C-storage in soil (0-30 cm) was estimated to 21.2-22.8 nig/ha in agri-silvicultre and recorded 44.4% gain over rice-wheat cropping system. Therefore, this study recommends E. tereticornis planting as a viable option for sustainable production and carbon mitigation.