Summary Aboveground respiration of five 8-year-old trees

of field-grown hinoki cypress (Chamaecyparis obtusa (Sieb. et Zucc.) Endl.) was nondestructively measured at monthly intervals over 1 year with an enclosed standing tree method. The relationship between monthly specific respiration rate and monthly mean relative growth rate at the individual tree level was described by a linear equation. During the dormant season, respiration was used mainly for maintenance purposes, whereas during the growing season, more than 40% of the respiration was used for growth purposes, i.e., 60 to 70% in May. We conclude that annual maintenance and growth respiration of a tree are directly proportional to the aboveground phytomass and its annual increment, respectively. The maintenance coefficient was estimated to be 0.504 ± 0.039 (SE) kg kg year, indicating that the amount respired for maintaining already existing phytomass was equivalent to about half of the existing phytomass. The growth coefficient was estimated to be 0.772 ± 0.043 (SE) kg kg, indicating that the amount respired for constructing new phytomass was equivalent to about three-fourths of the annual phytomass increment. The annual stand maintenance and growth respiration were, respectively, 8.8 Mg ha year for an aboveground biomass of 17.4 Mg ha and 5.0 Mg ha year for an annual stand aboveground biomass increment of 6.5 Mg ha year. About twothirds of the total respiration was used to maintain already existing biomass, and about one-third was used to construct new biomass.