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

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.

What Are the Principal Factors Affecting Ambient Ozone Concentrations in Czech Mountain Forests?

“…European-wide assessment shows that, ambient O 3 exposures recorded at Czech background rural sites are medium in European context, being lower than in Southern Europe including Mediterranean, but higher than in Scandinavia, similar as in Germany and Switzerland (e.g., Waldner et al, 2007;Baumgarten et al, 2009;EEA, 2016). In our earlier work we assessed long-term time trends and spatial variability in ambient O 3 concentrations throughout the Czech Republic (Hůnová and Bäumelt, 2018), O 3 exposure over Czech forested areas , compared different GIS methods to create a reliable O 3 and AOT40F map based on observed data , studied O 3 exposure, stomatal flux, and ozone injury on native vegetation in mountain forests (Hůnová et al, 2011;Vlasáková-Matoušková and Hůnová, 2015;Hůnová, 2017), and indicated the Czech forest regions which are stressed by permanent high O 3 exposures (Hůnová et al, 2019).…”

“…equivocal (Šrámek et al, 2007Hůnová et al, 2010Hůnová et al, , 2011Zapletal et al, 2012;Vlasáková-Matoušková and Hůnová, 2015), however, and despite the high O 3 levels recorded, no serious damage attributable to O 3 has been reported so far.…”

Spatial and temporal trends of ozone distribution in the Jizerské hory Mountains of the Czech Republic

“…In our earlier study focused on examining visible symptoms on native vegetation growing in the area, the damage we found, however, was much less than expected considering the recorded O 3 levels (Matoušková et al 2010). The symptoms attributable to O 3 were scarce and confirmed microscopically as ozone-induced (Günthardt-Goerg and Vollenweider 2007) only on two species, Fagus sylvatica and Rubus idaeus (Hůnová et al 2011;Vlasáková-Matoušková and Hůnová 2015). The crucial question regarding this aspect is amount of ozone (dose) getting inside plants (Launiainen et al 2013).…”

Ambient Air Quality in the Czech Republic: Past and Present

“…According to recommendations given by Krupa and Legge [179], these were used for indicative measurements within environmental studies conducted in protected natural areas (the Jizerské hory Mts., Orlické hory Mts., Novohradské hory Mts. andČeské Švýcarsko National Park), in complex, less accessible terrain in forested mountain areas without electricity available for standard measurements, and proved very successful, offering high precision and accuracy [180][181][182][183].…”

“…To date, published papers on the O 3 biological effects on Czech forests are ambiguous [183][184][185][186][187][188]. However, despite the fact that the recorded O 3 concentrations are fairly high, no serious harmful effects attributable to O 3 have been published so far.…”