Photosynthate allocation in Pinustaeda. I. Substrate requirements for synthesis of shoot biomass

Abstract

Procedures were developed to estimate the amount of glucose substrate required to biosynthesize shoot biomass of Pinustaeda L. By using compositional data from our own analyses and from the literature, glucose requirements per gram of major biomass constituent fractions were calculated to be as follows: lipids, 3.019 g; phenolics, 1.919 g; lignin, 1.897 g; nitrogenous compounds, 1.579 g; organic acids, 1.484 g; and carbohydrates, 1.182 g. From determinations of shoot weight and composition we calculated that 1.574 g of glucose was required to produce 1 g of typical shoot biomass.The computational procedures were also applied to analytical data from four other tree species, with glucose requirements estimated to range from 1.216 g for the cambial zone of Eucalyptusregnans F. Muell. to 1.603 g for bark of Pinuselliottii Englm.Application of our findings to studies of biomass formation of forest trees are discussed.