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O3, CO2 and chemical fractionation in ponderosa pine saplings
Citation:
OLSZYK, D. M., D. T. TINGEY, AND M. G. JOHNSON. O3, CO2 and chemical fractionation in ponderosa pine saplings. Presented at APGC Symposium: Plant functioning in a changing global environment, Creswick, AUSTRALIA, December 07 - 11, 2008.
Impact/Purpose:
Environmental factors can affect plant tissue quality which is important for quality of organic matter inputs into soil food webs and decomposition of soil organic matter.
Description:
Environmental factors can affect plant tissue quality which is important for quality of organic matter inputs into soil food webs and decomposition of soil organic matter. Thus the effects of increases in CO2 and O3 and their interactions were determined for various chemical fractions in needles, branches, stems, and roots of ponderosa pine (Pinus ponderosa) saplings. Tissue samples were obtained after three growing seasons of treatment, dried and processed through a series of extractions and analyses to quantify non-polar, polar, cellulose, lignin, ash, phenolic, sugar and amino nitrogen fractions. The % carbon and nitrogen in the starting material; and polar, nonpolar, and acid hydrolysis residues were measured. Needle and stem ages, and root size class all had significant effects on chemical fractionation, but the pollutants had little impact. The significant (p<0.05) effects were O3-induced reductions in needle amino nitrogen and non-polar residue nitrogen concentrations, and CO2 x O3 interactions on amino nitrogen and non-polar residue carbon in needles which had senesced from the saplings. Thus, this study indicated that while O3 affected some forms of leaf nitrogen, a doubling of CO2 coupled with O3 did not affect woody tissues or roots.