Full text of this article is only available in PDF format.

Virpi Palomäki (email), Toini Holopainen, Seppo Kellomäki, Kaisa Laitinen

First-year results on the effects of elevated atmospheric CO2 and O3 concentrations on needle ultrastructure and gas exchange responses of Scots pine saplings.

Palomäki V., Holopainen T., Kellomäki S., Laitinen K. (1996). First-year results on the effects of elevated atmospheric CO2 and O3 concentrations on needle ultrastructure and gas exchange responses of Scots pine saplings. Silva Fennica vol. 30 no. 2–3 article id 5580. https://doi.org/10.14214/sf.a9225

Abstract

The effects of realistically elevated O3 and CO2 concentrations on the needle ultrastructure and photosynthesis of ca. 20-year-old Scots pine (Pinus sylvestris L.) saplings were studied during one growth period in open-top field chambers situated on a natural pine heath at Mekrijärvi, in eastern Finland. The experiment included six different treatments: chamberless control, filtered air, ambient air and elevated O3, CO2 and O3 + CO2. Significant increases in the size of chloroplast and starch grains were recorded in the current-year needles of the saplings exposed to elevated CO2 These responses were especially clear in the saplings exposed to elevated O3 + CO2 concentrations. These treatments also delayed the winter hardening process in cells. In the shoots treated with O3, CO2 and combined O3 + CO2 the Pmax was decreased on average by 50% (ambient CO2) and 40% (700 ppm CO2). Photosynthetic efficiency was decreased by 60% in all the treated shoots measured under ambient condition and by 30% in the CO2 and O3 + CO2 treated shoots under 700 ppm. The effect of all the treatments on photosynthesis was depressive which was probably related to evident accumulation of starch in the chloroplasts of the pines treated with CO2 and combined O3 + CO2. But in O3 treated pines, which did not accumulate starch in comparison to pines subjected to ambient air conditions, some injuries may be already present in the photosynthetic machinery.

Keywords
Pinus sylvestris; climate change; Scots pine; CO2; ozone; needle ultrastructure; gas exhange

Published in 1996

Views 4378

Available at https://doi.org/10.14214/sf.a9225 | Download PDF

Creative Commons License CC BY-SA 4.0

Register
Click this link to register to Silva Fennica.
Log in
If you are a registered user, log in to save your selected articles for later access.
Contents alert
Sign up to receive alerts of new content

Your selected articles
Your search results
Palomäki V., Holopainen T. et al. (1996) First-year results on the effects of elevated at.. Silva Fennica vol. 30 no. 2–3 article id 5580
Holopainen T., (1981) Alterations in the ultrastructure of epiphytic l.. Silva Fennica vol. 15 no. 4 article id 5149
Palomäki V., Hassinen A. et al. (1998) Open-top chamber fumigation system for exposure .. Silva Fennica vol. 32 no. 3 article id 681