For the calculation of increase in biomass you need to consider a few factors like biomass expansion factor etc. General equation is given by

Aboveground biomass density (t/ha) = VOB * WD * BEF

where:

WD = volume-weighted average wood density (1 of oven-dry biomass per m

BEF = biomass expansion factor (ratio of aboveground oven-dry biomass of trees to oven-dry biomass of inventoried volume)

For details

www.fao.org

Aboveground biomass density (t/ha) = VOB * WD * BEF

where:

WD = volume-weighted average wood density (1 of oven-dry biomass per m

^{3}green volume)BEF = biomass expansion factor (ratio of aboveground oven-dry biomass of trees to oven-dry biomass of inventoried volume)

For details

www.fao.org