Testing visible ozone injury within a Light Exposed Sampling Site as a proxy for ozone risk assessment for European forests

• 作者: Pierre Sicard Yasutomo Hoshika Elisa Carrari Alessandra De Marco Elena Paoletti
• 来源期刊: 林业研究（英文版）
• 年，卷（期）: 2021,（4）
• 所属期刊栏目: ORIGINAL PAPERS
• 页码范围: 1351-1359
• 页数: 9页
• 语种: 英文

摘要

Biologically meaningful and cost-effective indi-cators are needed for assessing and monitoring the impacts of tropospheric ozone (O 3 ) on vegetation and are required in Europe by the National Emission Ceilings Directive (2016). However, a clear understanding on the best suited indicators is missing. The MOTTLES ( MOnitoring ozone injury for seTTing new critical LEvelS ) project set up a new generation network for O 3 monitoring in forest plots in order to: 1) esti-mate the stomatal O 3 fluxes (Phytotoxic Ozone Dose above a threshold Y of uptake, PODY); and 2) collect visible foliar O 3 injury, both within the forest plot (ITP) and along the Light Exposed Sampling Site (LESS) along the forest edge. Nine forest sites at high O 3 risk were selected across Italy over 2017 ? 2019 and significant correlations ( p < 0.05) were found between the percentage of symptomatic plant spe-cies within the LESS, and POD1 (PODY, with Y = 1 nmol O 3 m ?2 s ?1 ) calculated for mixed forest species ( r = 0.53) and with the occurrence and severity of visible foliar O 3 injury on the dominant species in the plots ( r = 0.65). A generic flux-based critical level for mixed forest species was derived within the LESS and it was recommended using 11 mmol m ?2 POD1 as the critical level for forest protec-tion against O 3 injury, similar to the critical level obtained in the ITP (12 mmol m ?2 POD1). It was concluded that the frequency of symptomatic plant species within a LESS is a suitable and effective plant-response indicator of phytotoxic O 3 levels in forest monitoring. LESS is a non-destructive, less complex and less time-consuming approach compared to the ITP for monitoring foliar O 3 injury in the long term. Assessing visible foliar O 3 injury in the ITP might only underestimate the O 3 risk assessment at individual sites. These results are biologically meaningful and useful to monitoring experts and environmental policy makers.