Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): Woo-Jung Choi; Scott X. Chang; H. Lee Allen; Daniel L. Kelting; Hee-Myong Ro
    Date: 2005
    Source: Forest Ecology and Management 213: 90-101
    Publication Series: Miscellaneous Publication
    PDF: Download Publication  (870 KB)


    We examined 813C and 815N in needle (current and 1-year-old) and soil samples collected on two occasions (July and September 1999) from a 15-year-old loblolly pine (Pinus taeda L.) stand in an irrigation and fertilization experiment to investigate whether these treatments leave specific isotope signals in the samples and thus to infer the effects of treatments on C and N cycling. Irrespective of foliar age or sampling date, carbon isotope discrimination (A) was increased by irrigation, and decreased by fertilization. The carbon isotope discrimination model suggested that increased A by irrigation was due to decreased water use efficiency (WUE) through increased stomatal and/or mesophyll conductance. The decreased A by fertilization and published gas exchange measurements at the same site suggest that water stress resulting from increased water demand in the fertilized plots improved WUE through increased stomatal control of water loss. Foliar 815N values were not affected by irrigation, but were increased by fertilization. The 815N value of soil NH4 were higher than those of NO3 and were positively correlated with foliar 815N, suggesting that tree uptake of NH4* was one of the factors affecting foliar 815N. We conclude that irrigation and fertilization affected 813C and 815N values in plant and soil samples, reflecting changed C and N cycling patterns and water use efficiency in the studied loblolly pine stand.

    Publication Notes

    • You may send email to to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.


    Choi, Woo-Jung; Chang, Scott X.; Allen, H. Lee; Kelting, Daniel L.; Ro, Hee-Myong. 2005. Irrigation and fertilization effects on foliar and soil carbon and nitrogen isotope ratios in a loblolly pine stand. Forest Ecology and Management 213: 90-101


    13C/12C, 15N/14N, carbon isotope discrimination, nitrification, water use efficiency, Pinus taeda

    Related Search

    XML: View XML
Show More
Show Fewer
Jump to Top of Page