Comparing stem respiration and growth of jack pine provenances from northern and southern locations.

Stem respiration rates of 31-year-old jack pine (Pinus banksiana Lamb.) trees from northern and southern provenances growing in a common garden were compared. At 15 degrees C, the seasonal course of stem respiration rate of northern provenances was not statistically different from that of southern provenances. A relationship existed between maintenance respiration rate and stem growth rate. Because relationships between sapwood relative growth rate and annual growth and maintenance respiration rates were similar for northern and southern provenances, no clinal differences in stem respiration rates were observed.