© 1996 Heron Publishing—Victoria, Canada
Estimating stem maintenance respiration rates of dissimilar balsam fir stands
M. B. Lavigne (1), S. E. Franklin (2) and E. R. Hunt, Jr. (3)
1. Canadian Forest Service–Maritimes Region, Natural Resources Canada, P.O. Box 4000, Fredericton, N.B. E3B 5P7, Canada / 2. Department of Geography, University of Calgary, Calgary, AB T2N 1N4, Canada / 3. Department of Botany, University of Wyoming, Laramie, Wyoming 82071-3165, USA / Received September 12, 1995
Summary
Stem maintenance respiration rates were measured in five contrasting balsam fir (Abies balsamea (L.) Mill.) stands. At 15 °C, average respiration rates for individual stands ranged from 120 to 235 µmol m–3 s–1 when expressed per unit of sapwood volume, from 0.80 to 1.80 µmol m–2 s–1 when expressed per unit of stem surface area, and from 0.50 to 1.00 µmol g–1 s–1 when expressed per unit of nitrogen in the living stem biomass, but differences among stands were not statistically significant.
Coefficients of variation ranged from 50 to 100% within stands and were similar for all bases used to express respiration
rates. Coefficients of determination for regressions between chamber flux and chamber values of sapwood volume, stem surface
area and nitrogen content varied between stands and no one base was consistently higher than the other bases. We conclude
that the bases for expressing stem respiration are equally useful. Respiration rates were more closely correlated to stem
temperature observed approximately 2 h earlier than to current stem temperature. Among stands, annual stem maintenance respiration
per hectare varied from 0.1 to 0.4 Mmol ha–1 year–1, primarily because of large differences in sapwood volumes per hectare. Annual stem maintenance respiration per unit of leaf
area ranged from 3 to 6 mol m–2 year–1, increasing as sapwood volume per hectare increased.
Keywords:
Abies balsamea, carbon balance, maintenance respiration, temperature responses, woody-tissue respiration.
