Open-grown, maintained trees tend to have less above ground biomass than predicted by forest-derived biomass equations for trees of the same diameter at breast height (Nowak 1994). To adjust for this difference, biomass results for open-grown urban trees were multiplied by a factor of 0.8 (Nowak 1994). No adjustment was made for trees found in more natural stand conditions (e.g., vacant lands, forest preserves). Because deciduous trees drop their leaves annually, only carbon stored in woody biomass was calculated for these trees. Total tree dry weight biomass (above- and belowground) was converted to total stored carbon by multiplying by 0.5.