Prediction of long-term growth rates of larch clones by calorimetric measurement of metabolic heat rates

A linear correlation exists between long-term growth rates and calorimetrically measured metabolic heat rates in some clones of larch (Larixlaricina (Du Roi) K. Koch). The metabolic heat rate per gram of tissue was found to be highly variable among clones from different trees and reproducible for clones of the same tree. The ordering of metabolic rates for clones was shown to be independent of the physiological growth stage in which the measurements were made. Winter-hardened tissue was found to be immediately active on warming to room temperature.