title: Chemical and anatomical changes in Liquidambar styraciflua L. xylem after long term exposure to elevated CO2.
abstract: The anatomical and chemical characteristics of sweetgum were studied after 11 years of elevated CO2 (544 ppm, ambient at 391 ppm) exposure. Anatomically, branch xylem cells were larger for elevated CO2 trees, and the cell wall thickness was thinner. Chemically, elevated CO2 exposure did not impact the structural components of the stem wood, but non-structural components were significantly affected. Principal component analysis (PCA) was employed to detect differences between the CO2 treatments by considering numerous structural and chemical variables, as well as tree size, and data from previously published sources (i.e., root biomass, production and turnover). The PCA results indicated a clear separation between trees exposed to ambient and elevated CO2 conditions. Correlation loadings plots of the PCA revealed that stem structural components, ash, Ca, Mg, total phenolics, root biomass, production and turnover were the major responses that contribute to the separation between the elevated and ambient CO2 treated trees.
authors.affiliation: Center for Renewable Carbon, University of Tennessee, Knoxville, TN, USA.
authors.forename: Keonhee
authors.initials: K
authors.lastname: Kim
authors.affiliation: Center for Renewable Carbon, University of Tennessee, Knoxville, TN, USA. Electronic address: nlabbe@utk.edu.
authors.forename: Nicole
authors.initials: N
authors.lastname: Labbé
authors.affiliation: Climate Change Science Institute and Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Warren
authors.affiliation: USDA-Forest Service, Southern Research Station, Pineville, LA, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Elder
authors.affiliation: Center for Renewable Carbon, University of Tennessee, Knoxville, TN, USA.
authors.forename: Timothy G
authors.initials: TG
authors.lastname: Rials
mesh_terms: D000393:Air Pollutants / Q000032:analysis / Q000633:toxicity*; D018533:Biomass; D002245:Carbon Dioxide / Q000032:analysis / Q000633:toxicity*; D031317:Liquidambar / Q000033:anatomy & histology / Q000187:drug effects* / Q000502:physiology; D018517:Plant Roots / Q000737:chemistry; D052584:Xylem / Q000033:anatomy & histology / Q000187:drug effects* / Q000502:physiology
chemical_list: D000393:Air Pollutants; D002245:Carbon Dioxide
keywords: Chemical composition; Free air CO(2) enrichment; Hydraulic conductivity; PCA; Sweetgum