Biomass prediction using generalized allometric regressions for some northeast tree species

Generalized allometric equations for several tree species were developed to assess the feasibility of using such equations for sites other than those for which they were developed. Regressions relating weight of stem, branch, and total above ground biomass to DBH (diameter at breast height, 1.3 m) were compiled for six species from the literature and used to generate new generalized regressions by species and plant part. Mean differences between values predicted by the generalized regressions and estimates from original regressions for total above ground weight were generally within the range of errors of estimate reported for individual regressions. The generalized regressions do not introduce bias into the results with increasing dbh. Differences between the generalized regressions and the original regressions for stem and branch weights of all species were considerably higher. Tests of generalized regressions against field data for sugar maple and aspen indicate excellent prediction by a generalized maple regressions but somewhat less accurate predictions by generalized aspen regressions.