Dear Tim

Maybe the following will be useful:

Yakir, D and De Niro, M. J. (1990) Oxygen and hydrogen isotope
fractionation during cellulose metabolism in Lemma gibba. Plant
Physiology, 93, 325-332.

Cooper, L. W. and De Niro, M. J. (1989) Oxygen-18 content of
atmoshperic oxygen does not affect the oxygen isotope
relationship between environmental water and cellulose in a
submerged aquatic plant, Egeria densa Planch. Plant Physiology,
91 536-541.

the last one has no D/H, but may help too.

Jim Gillon

Dept. of Environmental Science and Energy Research
Weizmann Institute of Science
76100 Rehovot
Israel

Tel 972-8-9344227 or Fax 972-8-934 4124