Open AccessCarbon and oxygen isotope ratios of tree ring cellulose along a precipitation transect in Oregon, United States
Author(s) -
Roden John S.,
Bowling David R.,
McDowell Nate G.,
Bond Barbara J.,
Ehleringer James R.
Publication year - 2005
Publication title -
journal of geophysical research: biogeosciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2005jg000033
Subject(s) - cellulose , transect , dendrochronology , environmental science , precipitation , isotopes of oxygen , ecosystem respiration , environmental chemistry , chemistry , hydrology (agriculture) , ecosystem , ecology , geology , biology , primary production , geography , paleontology , organic chemistry , nuclear chemistry , meteorology , geotechnical engineering
The carbon and oxygen isotopic compositions of tree ring cellulose were examined for trees along a precipitation gradient in western Oregon, United States. Two years of cellulose from four sites dominated by coniferous forests ranging in precipitation from 227 to 2129 mm were sampled in conjunction with studies that measured the δ 18 O and δ 13 C of ecosystem respiration. The mean tree ring cellulose δ 13 C varied from −22.1 to −26.3‰ among sites and showed enrichment with decreasing water availability across the transect. The δ 13 C in cellulose varied across the precipitation transect in a similar pattern to the δ 13 C of leaf and root tissues as well as ecosystem respiration, although tree ring cellulose was enriched in 13 C by over 3‰ compared to other organic matter components. The mean tree ring cellulose δ 18 O varied from 28.1 to 30.3‰. However, trends of cellulose δ 18 O change with water availability were obscured by differences in stem water δ 18 O. When calculated as deviation from stem water (δ 18 O cellulose − δ 18 O stem water ) the differences in evaporative enrichment between sites was more pronounced (range of 9.6‰). The limited observed variation in tree ring cellulose δ 18 O of field grown trees despite large site difference in stem and leaf water δ 18 O across the transect agreed with predictions from a mechanistic model. Tree ring records of cellulose δ 18 O may provide useful proxy information regarding humidity and site water balance especially if combined with δ 13 C records that also vary with plant water status.