Skip to page content
USDA Forest Service
  
Treesearch

Research & Development Treesearch

 
Treesearch Home
About Treesearch
Contact Us
Research & Development
Forest Products Lab
International Institute of Tropical Forestry
Northern
Pacific Northwest
Pacific Southwest
Rocky Mountain
Southern Research Station
Help
 

GeoTreesearch


Science.gov - We Participate


USA.gov  Government Made Easy


Global Forest Information Service

US Forest Service
P.O. Box 96090
Washington, D.C.
20090-6090

(202) 205-8333

You are here: Home / Search / Publication Information
Bookmark and Share

Publication Information

(267 KB bytes)

Title: The effects of sodium erythorbate and ethylenediurea on photosynthetic function of ozone-exposed loblolly pine seedlings

Author: Kuehler, Eric A.; Flagler, R.B.

Date: 1998

Source: Environmental Pollution. 105(1999): 25-35.

Publication Series: Miscellaneous Publication

Description: In an open-top chamber study in east Texas, ozone-sensitive loblolly pine (Pinus taeda L.) seedlings were treated with either the antioxidant Ozoban (74.5 percent sodium erythorbate active ingredient (a.i.)) at 0, 1030, or 2060 mg liter- 1 or ethylenediurea (EDU 50 percent a.i.) at 0, 150, or 300 ppm every 2 weeks while being subjected to a range of ozone exposures beginning in April 1994. The ozone exposures included sub-ambient ozone levels (CF), approximate ambient (NF), and 1.5, 2.0, and 2.5 times ambient ozone (1.5% , 2.0% , and 2.5% , respectively). The response variables included net photosynthesis (A), stomatal conductance (g), chloroplast pigment concentration, and total foliar N concentration. Foliar injury due to ozone was observed early in the growing season, but subsided over time. Ozoban did not have any consistent effects throughout the experiment on the response variables, but did cause changes early in the study on gas exchange. Both g and A photosynthesis were greater at elevated ozone levels in seedlings treated with 1030 mg liter- 1 of Ozoban compared to those treated with either 0 or 2060 mg liter- 1 for the first sampling period in June. However, at CF, seedlings treated with 1030 mg liter- 1 of Ozoban showed signs of reduced A compared to the other antioxidant treatments. This indicates that sodium erythorbate may have a negative physiological effect on seedlings in a low ozone environment. For EDU-treated seedlings, no consistent antioxidant treatment effects were observed, but linear regression analysis indicates that EDU shows promise in providing protection from ozone injury. At 150 ppm, EDU may retard stomatal closure in younger pine seedlings. No consistent benefit was afforded to chloroplast pigments for the study by either antioxidant. Ozoban at 2060 mg liter- 1 appeared to have phytotoxic effects with regards to chlorophyll a and total carotenoids in the latter stages of the experiment. No significant Ozoban or EDU effects were observed with respect to total foliar N concentration until the final sampling period in October, where foliage treated with 300 ppm of EDU displayed higher N concentration at all ozone levels except 1.5% ambient ozone. Foliage treated with 150 ppm EDU showed the lowest nitrogen concentration in CF and NF, but the highest in 1.5% . Because of relatively low ozone exposures during the study year and the closeness with which the seedlings were grown, these results may not accurately represent the benefits of sodium erythorbate or EDU in reducing ozone stress in loblolly pine seedlings for field-grown trees.

Publication Notes:

  • 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.
  • You may send email to pubrequest@fs.fed.us to request a hard copy of this publication. (Please specify exactly which publication you are requesting and your mailing address.)

XML: View XML

Citation:


Kuehler, Eric A.; Flagler, R.B. 1998. The effects of sodium erythorbate and ethylenediurea on photosynthetic function of ozone-exposed loblolly pine seedlings. Environmental Pollution. 105(1999): 25-35.

 


 [ Get Acrobat ]  Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.