Abstarct In recognition of the rising threats of groundlevel ozone(O_(3))pollution to forests,agricultural crops,and other types of vegetation,accurate and realistic risk assessment is urgently needed.The accumulated ...Abstarct In recognition of the rising threats of groundlevel ozone(O_(3))pollution to forests,agricultural crops,and other types of vegetation,accurate and realistic risk assessment is urgently needed.The accumulated O_(3)exposure over a concentration threshold of 40 nmol mol-1(AOT40)is the most commonly used metric to investigate O3 exposure and its effects on vegetation and to conduct vegetation risk assessment.It is also used by international regulatory authorities for deriving critical levels and setting standards to protect vegetation against surface O_(3).However,fixed periods of the growing season are used universally,yet growing seasons vary with latitudes and elevations,and the periods of plant lifespan also differ among annual species.Here,we propose the concept of the Annual O_(3)Spectrum Profile(AO_(3)SP)and apply it to calculate the profile of AOT40 throughout the year(AAOT40SP,Annual AOT40 Spectrum Profile)using the International Organization for Standardization(ISO)weeks as a shorter window ISO-based accumulated exposure.Using moving time periods of three(for crops)or six(for forests)months,the i so AOT40 behavior throughout the year can be examined as a diagnostic tool for O_(3)risks in the short-or long-term during the lifecycle of local vegetation.From this analysis,AOT40(i so AOT40)that is most representative for the local conditions and specific situations can be identified,depending on the exact growing season and lifecycle of the target vegetation.We applied this novel approach to data from five background monitoring stations located at different elevations in Cyprus.Our results show that the AAOT40SP approach can be used for improved and more realistic assessment of O3 risks to vegetation.The AO_(3)SP approach can also be applied using metrics other than AOT40(exposure-or flux-based),adding a new dimension to the way O_(3)risk to vegetation is assessed.展开更多
Increasing tropospheric ozone concentration is a big threat to food security due to its phytotoxicity. It causes a huge damage to crop production across the globe, especially in the C3 plants (paddy (Oryza sativa)). T...Increasing tropospheric ozone concentration is a big threat to food security due to its phytotoxicity. It causes a huge damage to crop production across the globe, especially in the C3 plants (paddy (Oryza sativa)). The present study focuses on exposure-plant response index over different O3 concentration. In this study, two metrics viz. the average ozone for 7 h during daytime (M7) and accumulated exposure above a threshold of X ppb (AOTX) have been used in examining crop yield decline in Delhi, India. Eight AOTX indices (AOT0, AOT5, AOT10, AOT15, AOT20, AOT25, AOT30 and AOT40) were analysed and potential crop reduction was predicted. The regular monitoring of O3 was done for 24 hours in year 2013. As per the European benchmark, a 5% yield loss was expected when AOT40 values crosses 3000 ppb·h, however this study revealed that AOT40 threshold value ranged between 695 ppb to 17645 ppb which had exceeded the European benchmark in most of the months. The crop reduction was found to be ~6.3% as evaluated by AOT40 index, whereas, total AOTX contributed up to 23% of rice yield reduction in Delhi NCR. On the other side, only 2% of rice yield loss has been predicted using M7 index, which is not comparable with AOTX indices. The M7 index was also found incomparable to the calculated net yield loss (13%) for year 2013 to 2016. Hence, AOT40 may be a better index to predict the vulnerable impact of O3 into the crop production. The total vulnerability of O3 calculated as 57% in the crops reduction, while impacts of O3 was calculated and summed up for both the significant and non-significant paddy growing seasons. Hence, this study highlights an alarming situation in crop yield reduction due to O3 exposure in Delhi NCR which further threatens food security.展开更多
In Europe,tropospheric ozone pollution appears as a major air quality issue,and ozone concentrations remain potentially harmful to vegetation.In this study we compared the trends of two ozone metrics widely used for f...In Europe,tropospheric ozone pollution appears as a major air quality issue,and ozone concentrations remain potentially harmful to vegetation.In this study we compared the trends of two ozone metrics widely used for forests protection in Europe,the AOT40(Accumulated Ozone over Threshold of 40 ppb)which only depends on surface air ozone concentrations,and the Phytotoxic Ozone Dose which is the accumulated ozone uptake through stomata over the growing season,and above a threshold Y of uptake(PODY).By using a chemistry transport model,we found that European-averaged ground-level ozone concentrations(−2%)and AOT40 metric(−26.5%)significantly declined from 2000 to 2014,due to successful control strategies to reduce the emission of ozone precursors in Europe since the early 1990s.In contrast,the stomatal ozone uptake by forests increased from 17.5 to 26.6 mmol O3 m^(−2)despite the reduction in ozone concentrations,leading to an increase of potential ozone damage on plants in Europe.In a climate change context,a biologically-sound stomatal flux-based standard(PODY)as new European legislative standard is needed.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)(No.4210070867)The Startup Foundation forIntroducing Talent(No.003080)of Nanjing University of Information Science&Technology(NUIST),Nanjing,China+2 种基金the Jiangsu Distinguished Professor Program of the People s Government of Jiangsu Province,Chinathe Foreign 1000 Young Talents Program Fund(No.31950410547)of the NationalMinistry of Science and Technology,Chinathe project URBFLUX(PID2021-125941OB-I00,MINECO-FEDER)。
文摘Abstarct In recognition of the rising threats of groundlevel ozone(O_(3))pollution to forests,agricultural crops,and other types of vegetation,accurate and realistic risk assessment is urgently needed.The accumulated O_(3)exposure over a concentration threshold of 40 nmol mol-1(AOT40)is the most commonly used metric to investigate O3 exposure and its effects on vegetation and to conduct vegetation risk assessment.It is also used by international regulatory authorities for deriving critical levels and setting standards to protect vegetation against surface O_(3).However,fixed periods of the growing season are used universally,yet growing seasons vary with latitudes and elevations,and the periods of plant lifespan also differ among annual species.Here,we propose the concept of the Annual O_(3)Spectrum Profile(AO_(3)SP)and apply it to calculate the profile of AOT40 throughout the year(AAOT40SP,Annual AOT40 Spectrum Profile)using the International Organization for Standardization(ISO)weeks as a shorter window ISO-based accumulated exposure.Using moving time periods of three(for crops)or six(for forests)months,the i so AOT40 behavior throughout the year can be examined as a diagnostic tool for O_(3)risks in the short-or long-term during the lifecycle of local vegetation.From this analysis,AOT40(i so AOT40)that is most representative for the local conditions and specific situations can be identified,depending on the exact growing season and lifecycle of the target vegetation.We applied this novel approach to data from five background monitoring stations located at different elevations in Cyprus.Our results show that the AAOT40SP approach can be used for improved and more realistic assessment of O3 risks to vegetation.The AO_(3)SP approach can also be applied using metrics other than AOT40(exposure-or flux-based),adding a new dimension to the way O_(3)risk to vegetation is assessed.
文摘Increasing tropospheric ozone concentration is a big threat to food security due to its phytotoxicity. It causes a huge damage to crop production across the globe, especially in the C3 plants (paddy (Oryza sativa)). The present study focuses on exposure-plant response index over different O3 concentration. In this study, two metrics viz. the average ozone for 7 h during daytime (M7) and accumulated exposure above a threshold of X ppb (AOTX) have been used in examining crop yield decline in Delhi, India. Eight AOTX indices (AOT0, AOT5, AOT10, AOT15, AOT20, AOT25, AOT30 and AOT40) were analysed and potential crop reduction was predicted. The regular monitoring of O3 was done for 24 hours in year 2013. As per the European benchmark, a 5% yield loss was expected when AOT40 values crosses 3000 ppb·h, however this study revealed that AOT40 threshold value ranged between 695 ppb to 17645 ppb which had exceeded the European benchmark in most of the months. The crop reduction was found to be ~6.3% as evaluated by AOT40 index, whereas, total AOTX contributed up to 23% of rice yield reduction in Delhi NCR. On the other side, only 2% of rice yield loss has been predicted using M7 index, which is not comparable with AOTX indices. The M7 index was also found incomparable to the calculated net yield loss (13%) for year 2013 to 2016. Hence, AOT40 may be a better index to predict the vulnerable impact of O3 into the crop production. The total vulnerability of O3 calculated as 57% in the crops reduction, while impacts of O3 was calculated and summed up for both the significant and non-significant paddy growing seasons. Hence, this study highlights an alarming situation in crop yield reduction due to O3 exposure in Delhi NCR which further threatens food security.
基金carried out with the contribution of the LIFE financial instrument of the European Union in the framework of the MOTTLES project“Monitoring ozone injury for setting new critical levels”(LIFE15 ENV/IT/000183).
文摘In Europe,tropospheric ozone pollution appears as a major air quality issue,and ozone concentrations remain potentially harmful to vegetation.In this study we compared the trends of two ozone metrics widely used for forests protection in Europe,the AOT40(Accumulated Ozone over Threshold of 40 ppb)which only depends on surface air ozone concentrations,and the Phytotoxic Ozone Dose which is the accumulated ozone uptake through stomata over the growing season,and above a threshold Y of uptake(PODY).By using a chemistry transport model,we found that European-averaged ground-level ozone concentrations(−2%)and AOT40 metric(−26.5%)significantly declined from 2000 to 2014,due to successful control strategies to reduce the emission of ozone precursors in Europe since the early 1990s.In contrast,the stomatal ozone uptake by forests increased from 17.5 to 26.6 mmol O3 m^(−2)despite the reduction in ozone concentrations,leading to an increase of potential ozone damage on plants in Europe.In a climate change context,a biologically-sound stomatal flux-based standard(PODY)as new European legislative standard is needed.
