© 1991 Heron Publishing—Victoria, Canada
Foliage dark respiration in Abies amabilis (Dougl.) Forbes: variation within the canopy
J. Reneé Brooks (1), Thomas M. Hinckley (1), E. David Ford (2) and Douglas G. Sprugel (1)
1. College of Forest Resources, AR-10, University of Washington, Seattle, WA 98195, USA / 2. Center for Quantitative Sciences, HR-20, University of Washington, Seattle, WA 98195, USA / Received January 25, 1991
Summary
Dark respiration of foliage was measured in a 30-year-old stand of Abies amabilis in western Washington from June to November. Both laboratory and field measurements were used to study the effect of environmental
and tree variables on respiration. Foliage respiration rates were most strongly influenced by needle temperature. After accounting
for leaf temperature differences, foliage respiration decreased with depth in the canopy for all age classes of foliage. Respiration
differences attributed to location within the canopy were greatest early in the growing season, but were still significant
in November. Younger foliage respired more than older foliage in the upper canopy, but not in the lower canopy. Respiration
differences due to foliage age were highly significant in the early growing season, but were not detectable by mid-October.
