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Stomatal ozone flux and visible leaf injury in native juvenile trees of Fagus sylvatica L.: a field study from the Jizerske hory Mts., the Czech Republic

Author:
Vlasáková-Matoušková, Leona, Hůnová, Iva
Source:
Environmental science and pollution research international 2015 v.22 no.13 pp. 10034-10046
ISSN:
0944-1344
Subject:
Fagus sylvatica, air, air temperature, altitude, forest ecosystems, humidity, juveniles, leaves, ozone, stomatal conductance, trees, Czech Republic
Abstract:
The study was carried out at six sites in the Jizerskehory Mts. in the north of the Czech Republic. At all these sites, ranging in altitude between 460 and 962 m a. s. l., and during the period from June to September in 2008, O₃ concentrations and environmental parameters important for accumulated stomatal O₃ flux (AFₛₜ) into Fagus sylvatica leaves were measured. At five sites, visible injury on Fagus sylvatica L. juvenile tree leaves was observed. A combination of actual O₃ levels in the Jizerkehory Mts. and environmental conditions, though relative air humidity and air temperature significantly limited stomatal conductance, has been sufficient enough to cause O₃ uptake exceeding the critical level (CL) for forest ecosystems. The AFₛₜ values ranged between 13.4 and 22.3 mmol O₃ m⁻². The CL for the accumulated stomatal flux of O₃ above a flux threshold 1.6 nmol m⁻² s⁻¹ (AFₛₜ1.6) was exceeded at all sites from ca 45 to 270 % (160 % on average). The CL of 5 ppm h⁻¹ for AOT40 (accumulated O₃ exposure above threshold of 40 ppb) was exceeded at four sites. The relationship between visible injury on O₃ indices was found. The conclusions based on AOT40 and AFSₜ are not the same. AFSₜ has been determined as better predictor of visible injury than AOT40.
Agid:
4401568