© 1989 Heron Publishing—Victoria, Canada
Pine needle holders for use in gas exchange measurements
Nelson T. Edwards
Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA / Received January 26, 1989
Summary
Simple holders for positioning pine needles in a gas exchange cuvette are described. The holders make it easy to enclose a
standard length of needles in the cuvette in a single plane without mutual shading. The holders also make it possible, following
gas exchange measurements, to harvest for further analysis just those needle portions that were enclosed in the leaf chamber.
Field observations, which were made with a gas exchange cuvette incorporating the needle holders, on the relationship between
carbon exchange rate and photon flux density in loblolly pine (Pinus taeda L.) needles are reported.
