Abstract
A three-year study was initiated in 1987 to evaluate the impact of O 3, acidic precipitation, and soil Mg on ectomycorrhizal colonization of loblolly pine ( Pinus taeda L.) seedlings. Thirty-six open-top chambers equipped with a rainfall exclusion/addition system were utilized to administer three levels of O 3 (subambient, ambient, or twice ambient) and two precipitation acidity levels (pH 3·8 or 5·2) to seedlings growing in 24-liter plastic pots containing soil having either 35 or 15 mg kg −1 of exchangeable Mg. Seedlings exposed to the twice ambient O 3 treatment exhibited smaller percentages of total ectomycorrhizal short roots at the end of each year of the study, but trends were statistically significant in 1989 only. Changes in number of specific ectomycorrhizal morphotypes in response to O 3 were not consistent from year to year. Acidic precipitation treatments had no effect on number or percent of mycorrhizal short roots, and responses of two morphotypes to soil Mg treatments were probably due to differences in the soil environment rather than a result of changes in aboveground processes. Temporal shifts in morphotype frequencies were observed for seedlings in all treatments and indicate that mycorrhizal succession occurred during the study period.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.