© 1992 Heron Publishing—Victoria, Canada
Long-term respiration in relation to growth and maintenance processes of the aboveground parts of a hinoki forest tree
Samuel Arung Paembonan (1, 2), Akio Hagihara (2, 3) and Kazuo Hozumi (2)
1. Department of Forestry, Faculty of Agriculture, Hasanuddin University, Ujung Pandang, Indonesia / 2. Department of Forestry, Faculty of Agriculture, Nagoya University, Chikusa, Nagoya 464-01, Japan / 3. Author to whom reprint requests should be addressed / Received December 10, 1990
Summary
Over a three-year period, CO2 exchange rates were measured continuously on the aboveground parts of a 13-year-old hinoki (Chamaecyparis obtusa (Sieb. et Zucc.) Endl.) tree in the field, using an open gas-exchange system tracking ambient temperature. The relationship
between daily aerial respiratory consumption and daily gross production, which was analyzed monthly, closely resembled McCree’s
equation. The value of the coefficient of growth respiration ranged between 0.0 in winter and 0.16 in summer and increased
with increasing monthly mean temperature. A clockwise loop was observed for monthly change in the relationship between the
coefficient of growth respiration and temperature. Maintenance respiration could be formulated as a power function of aboveground
dry weight. The exponent of the equation ranged from 0.3 to 1.1. A value of 1.1 in May and June, when trees were growing most
actively, indicated that maintenance respiration was directly proportional to aboveground weight. In March, April, July, and
August, maintenance respiration was not proportional to aboveground weight, but it was closely proportional to surface area.
The exponent value exhibited seasonal change with a clockwise loop in response to monthly average temperature. During the
dormant season, respiration was used only for maintenance purposes, whereas during the growing season both growth and maintenance
respiration occurred. Annual growth and maintenance respiration increased with increasing tree age. The average annual contribution
to total respiratory consumption was 21% for growth respiration and 79% for maintenance respiration.
