Carbon balance of the aerial parts of a young hinoki cypress (Chamaecyparis obtusa) stand.

The aerial carbon balance of a 9-year-old hinoki cypress (Chamaecyparis obtusa (Sieb. et Zucc.) Endl.) stand with an aerial biomass of 24.6 Mg(DW) ha(-1) was studied over a 1-year period. Various components that constitute gross production were measured on the basis of the summation method. Respiration of the aerial parts of six sample trees was measured at monthly intervals by an enclosed standing-tree method. The aerial respiration of sample trees was partitioned into growth and maintenance respiration by a two-component model. The growth coefficient varied between 1.2791 and 1.7957 g CO(2) g(DW) (-1) giving a mean value of 1.5223 +/- 0.0729 (SE) g CO(2) g(DW) (-1), whereas the maintenance coefficient ranged between 0.0200 and 0.0373 g CO(2) g(DW) (-1) month(-1) with a mean value of 0.0299 +/- 0.0031 (SE) g CO(2) g(DW) (-1) month(-1). Growth and maintenance respiration of the stand were estimated to be 8.62 and 10.52 Mg CO(2) ha(-1) year(-1), respectively. An open-top cloth trap method was employed to measure the death of the parts of five sample trees. The death of leaves and total organs in the stand were assessed to be 6.26 and 7.60 Mg(DW) ha(-1) year(-1), respectively. Tree mortality and biomass increment were 1.47 and 4.64 Mg(DW) ha(-1) year(-1), respectively. In terms of carbon, respiration, death, grazing and biomass increment were equivalent to 5.22, 4.53, 0.04 and 2.32 Mg C ha(-1) year(-1), respectively. Net production and gross production were estimated to be 6.89 and 12.11 Mg C ha(-1) year(-1), respectively. Biomass accumulation ratio (biomass/net production) and overall efficiency (net production/gross production) were 1.8 and 0.57, respectively.