Ozone effects on Aleppo pine seedlings (Pinus halepensisMill.) grown in open-top chambers

✍ Scribed by S. Elvira; R. Alonso; R. Inclan; V. Bermejo; F. J. Castillo; B. S. Gimeno

• Book ID: 104782418
• Publisher: Springer Netherlands
• Year: 1995
• Tongue: English
• Weight: 387 KB
• Volume: 85
• Category: Article
• ISSN: 0049-6979
• DOI: 10.1007/bf00477175

✦ Synopsis

A three-year term experiment was performed in eastern Spain to assess the effects of ozone (03) on the physiological behaviour of Aleppo pine (Pinus halepensis). Seedlings of this species were enclosed in opentop chambers during the summer and exposed to either Charcoal Filtered Air (CFA) to exclude 03, Non Filtered Air (NFA) or Non Filtered Air plus 40 ppb 03, 9h/day, 5 days/week (NFA+40). Gas exchange, foliar chlorophyll and nutrient levels were measured throughout the year. Clear seasonal fluctuations were observed since chlorophyll levels, stomatal conductance and net photosynthesis rates were lower during the summer, and higher in winter. O3-induced effects were apparent on previous year needles from the second year of exposure. A reduction in net photosynthesis, stomatal conductance, chlorophyll, N and P was found in the NFA+40 plots. The results showed the sensitivity of this species to ozone, since a three-month exposure to realistic 03 concentrations over three consecutive years induced important alterations in Aleppo pine performance. The application of the results to the definition of a critical O3 level for forest trees is discussed.