About Us | Help Videos | Contact Us | Subscriptions
 

Abstract

 

This article in JEQ

  1. Vol. 28 No. 5, p. 1548-1555
     
    Received: Sept 17, 1998


    * Corresponding author(s): tom.nash@asu.edu
 View
 Download
 Alerts
 Permissions
 Share

doi:10.2134/jeq1999.00472425002800050020x

Physiological Effects of the Mexico City Atmosphere on Lichen Transplants on Oaks

  1. A. Zambrano,
  2. T. H. Nash * and
  3. C. Gries
  1. Department of Plant Biology, Arizona State Univ., Tempe, AZ 85287-1601.

Abstract

Abstract

Two lichen species, Usnea ceratina Ach. and Everniastrum neocirrhatum (Hale M. Wirth) Hale ex Sipman, were transplanted for 54 d into an oak forest (Quercus rugosa) in the vicinity of Mexico City to assess their ability to survive near a highly polluted urban environment. Net photosynthesis based on dry weight and chlorophyll b decreased respectively ca. 30 and 25% compared with control samples in a less polluted site, ca. 100 km north of Mexico City. There was no interspecific difference in the response of carbon fixation, but E. neocirrhatum was more sensitive to chlorophyll b degradation near Mexico City than U. ceratina. Chlorophyll a was also degradated (ca. 15%) near Mexico City. Changes in total carotenes were mostly dependent on species and time rather than on location. High concurrent levels of ozone and sulfur dioxide in the air are discussed as possible causes of the decline in the lichen photosynthesis and chlorophyll content.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © .