A 400-year-old Douglas-fir tree and its epiphytes: biomass, surface area, and their distributions

Methods have been developed to yield total tree estimates of biomass for various componentsof a tree (trunk, axes, twigs, and needles) and its community of epiphytes (microorganisms,lichens, and bryophytes). Trees were sampled with the help of climbing techniques modifiedfrom mountain climbing. Two stages of sampling were involved. First, all units of the popula-tion were described so that their weights could be predicted. Second, several units were chosenwith probability of selection dependent upon predicted weight and sampled in detail. Biomassestimates from the sampled units were expanded to tree totals with information gathered duringthe first sampling stage. Internal structure of the crown (tree components and epiphytes) isillustrated by maps of trunk and branch systems and by diagrams of horizontal and verticaldistributions. This internal structure was also derived from the first sampling stage.
These methods have been applied to nine old-growth Douglas fir trees (Pseudotsuga menziesii(Mirb.) Franco). Data from a single 400-year-old tree (1.46 m dbh, 77 m in height) in the H. J.Andrews Experimental Forest in the western Cascade Mountains of Oregon are presented.Biomass and surface area estimates are as follows: trunk, 26 870 kg, 223 m2; axes ( > 4 cm),1530 kg, 81 m2; living twigs (