Main content area

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

Vlasáková-Matoušková, Leona, Hůnová, Iva
Environmental science and pollution research international 2015 v.22 no.13 pp. 10034-10046
Fagus sylvatica, air, air temperature, altitude, forest ecosystems, humidity, juveniles, leaves, ozone, stomatal conductance, trees, Czech Republic
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.