Cryptomeria japonica D. Don trees shoot biomass partitioning in a stand located in southeastern Paraná

Resumo

The purpose of this study was to evaluate the partitioning of individual dry aboveground biomass in Cryptomeria japonica trees, as on its compartments as well as in the vertical profile, and examine whether the Pipe Model Theory, which states a rule between the plant organs, applies to the present case. Data were collected in a plantation established in 1984 in Rio Negro - PR. Twenty representative trees of the population distributed by diameter class were felled and weighed in the field, and their dry biomass were analyzed according to horizontal layers of 5 m wide in the following biomass compartments: sapwood, heartwood, bark, branches and foliage. Biomass is mostly composed by the stem (73.67%). In the wood, 41.66% of the biomass corresponds to sapwood, 26.66% to heartwood and 5.35% to bark. The canopy accounts for 26.33% of the dry biomass, which is represented at 13.75% by branches and 12.58% by foliage. In the first five meters tree biomass is comprised exclusively of wood and bark. From 5 m crown begins to have partici­pation in biomass, becoming the major fraction from 15 m and above in the vertical profile. The partitioning of biomass in heartwood decreases along the vertical profile of the tree, i.e., it is largest at the base and smaller in the lower stratum. This study indicates that the Pipe Model Theory applies to the Cryptomeria japonica forest stand.