Inconsistency between process-based model and dose-response function in estimating biomass losses in Northern Hemisphere due to elevated O.

Tropospheric ozone (O) concentrations in the Northern Hemisphere have significantly increased since the pre-industrial era, with ongoing growth driven by emissions from industrial, agricultural, and transportation activities, further exacerbated by the warming temperatures and altered atmospheric circulation patterns associated with climate change. This study compared different methodologies for estimating biomass potential losses (BPL) in forests due to elevated O using both concentration-based (AOT40) and flux-based (POD1) metrics. Moreover, to further assess the impact of O on forest health and carbon uptake across the dominant forest types in the Northern Hemisphere, we also compared BPL estimates from dose-response functions with those derived from the process-based model ORCHIDEE.

Unraveling the difference of sensitivity to ozone between non-hybrid native poplar and hybrid poplar clones: A flux-based dose-response analysis.

Poplars are economically important tree crops and biologically important model plants, which are known to be sensitive to ozone (O). Although surface O is considered as a significant global environmental issue because of its phytotoxicity and greenhouse effect, the knowledge of the dose-response (DR) relationships in poplars for the assessment of O risk is still limited. Hence, this study aimed at collecting data of studies with manipulative O exposures of poplars within FACE (Free Air Concentration Enhancement) and OTC (Open-Top Chamber) facilities.

Fungal community composition predicts forest carbon storage at a continental scale.

Forest soils harbor hyper-diverse microbial communities which fundamentally regulate carbon and nutrient cycling across the globe. Directly testing hypotheses on how microbiome diversity is linked to forest carbon storage has been difficult, due to a lack of paired data on microbiome diversity and in situ observations of forest carbon accumulation and storage. Here, we investigated the relationship between soil microbiomes and forest carbon across 238 forest inventory plots spanning 15 European countries.

Drought mitigates the adverse effects of O on plant photosynthesis rather than growth: A global meta-analysis considering plant functional types.

Tropospheric ozone (O ) is a phytotoxic air pollutant adversely affecting plant growth. High O exposures are often concurrent with summer drought. The effects of both stresses on plants are complex, and their interactions are not yet well understood.

Lichen Biodiversity and Near-Infrared Metabolomic Fingerprint as Diagnostic and Prognostic Complementary Tools for Biomonitoring: A Case Study in the Eastern Iberian Peninsula.

In the 1990s, a sampling network for the biomonitoring of forests using epiphytic lichen diversity was established in the eastern Iberian Peninsula. This area registered air pollution impacts by winds from the Andorra thermal power plant, as well as from photo-oxidants and nitrogen depositions from local and long-distance transport. In 1997, an assessment of the state of lichen communities was carried out by calculating the Index of Atmospheric Purity.

Machine learning model to predict vehicle electrification impacts on urban air quality and related human health effects.

Air pollution is a prevailing environmental problem in cities worldwide. The future vehicle electrification (VE), which in Europe will be importantly fostered by the ban of thermal engines from 2035, is expected to have an important effect on urban air quality. Machine learning models represent an optimal tool for predicting changes in air pollutants concentrations in the context of future VE.

Trends in urban air pollution over the last two decades: A global perspective.

Ground-level ozone (O), fine particles (PM), and nitrogen dioxide (NO) are the most harmful urban air pollutants regarding human health effects. Here, we aimed at assessing trends in concurrent exposure of global urban population to O, PM, and NO between 2000 and 2019. PM, NO, and O mean concentrations and summertime mean of the daily maximum 8-h values (O MDA8) were analyzed (Mann-Kendall test) using data from a global reanalysis, covering 13,160 urban areas, and a ground-based monitoring network (Tropospheric Ozone Assessment Report), collating surface O observations at nearly 10,000 stations worldwide.

Ozone pollution threatens the production of major staple crops in East Asia.

East Asia is a hotspot of surface ozone (O) pollution, which hinders crop growth and reduces yields. Here, we assess the relative yield loss in rice, wheat and maize due to O by combining O elevation experiments across Asia and air monitoring at about 3,000 locations in China, Japan and Korea. China shows the highest relative yield loss at 33%, 23% and 9% for wheat, rice and maize, respectively.

Global COVID-19 lockdown highlights humans as both threats and custodians of the environment.

The global lockdown to mitigate COVID-19 pandemic health risks has altered human interactions with nature. Here, we report immediate impacts of changes in human activities on wildlife and environmental threats during the early lockdown months of 2020, based on 877 qualitative reports and 332 quantitative assessments from 89 different studies. Hundreds of reports of unusual species observations from around the world suggest that animals quickly responded to the reductions in human presence.

Urban population exposure to air pollution in Europe over the last decades.

Background: The paper presents an overview of air quality in the 27 member countries of the European Union (EU) and the United Kingdom (previous EU-28), from 2000 to 2017. We reviewed the progress made towards meeting the air quality standards established by the EU Ambient Air Quality Directives (European Council Directive 2008/50/EC) and the World Health Organization (WHO) Air Quality Guidelines by estimating the trends (Mann-Kendal test) in national emissions of main air pollutants, urban population exposure to air pollution, and in mortality related to exposure to ambient fine particles (PM) and tropospheric ozone (O).

Results: Despite significant reductions of emissions (e.

Ozone affects plant, insect, and soil microbial communities: A threat to terrestrial ecosystems and biodiversity.

Elevated tropospheric ozone concentrations induce adverse effects in plants. We reviewed how ozone affects (i) the composition and diversity of plant communities by affecting key physiological traits; (ii) foliar chemistry and the emission of volatiles, thereby affecting plant-plant competition, plant-insect interactions, and the composition of insect communities; and (iii) plant-soil-microbe interactions and the composition of soil communities by disrupting plant litterfall and altering root exudation, soil enzymatic activities, decomposition, and nutrient cycling. The community composition of soil microbes is consequently changed, and alpha diversity is often reduced.

Yield and economic losses of winter wheat and rice due to ozone in the Yangtze River Delta during 2014-2019.

Ground-level ozone (O) is the main phytotoxic air pollutant causing crop yield reduction in China. As the main grain producing area in China, the Yangtze River Delta (YRD) is facing serious O pollution. This study analyzed the hourly ground-level O observation data of 158 stations from 2014 to 2019 in YRD, and grain production data of 193 districts and counties.

Ozone exposure, nitrogen addition and moderate drought dynamically interact to affect isoprene emission in poplar.

Ozone (O) pollution can induce changes in plant growth and metabolism, and in turn, affects isoprene emission (ISO), but the extent of these effects may be modified by co-occurring soil water and nitrogen (N) availability. To date, however, much less is known about the combined effects of two of these factors on isoprene emission from plants. We investigated for the first time the combined effects of O exposure (CF, charcoal-filtered air; EO, non-filtered air plus 40 ppb of O), N addition (N0, no additional N; N50, 50 kg ha year of N) and moderate drought (WW, well-watered; WR, 40% of WW irrigation) on photosynthetic carbon assimilation and ISO emission in hybrid poplar at both leaf- and plant-level over time.

Amplified ozone pollution in cities during the COVID-19 lockdown.

The effect of lockdown due to coronavirus disease (COVID-19) pandemic on air pollution in four Southern European cities (Nice, Rome, Valencia and Turin) and Wuhan (China) was quantified, with a focus on ozone (O). Compared to the same period in 2017-2019, the daily O mean concentrations increased at urban stations by 24% in Nice, 14% in Rome, 27% in Turin, 2.4% in Valencia and 36% in Wuhan during the lockdown in 2020.

Yield and economic losses in maize caused by ambient ozone in the North China Plain (2014-2017).

Maize is the second most important crop per harvested area in the world. The North China Plain (NCP) is a highly populated and relevant agricultural region in China, experiencing some of the highest ozone (O) concentrations worldwide. It produces ~24% of the total maize production of China in years 2014-2017.

Assessment of O-induced yield and economic losses for wheat in the North China Plain from 2014 to 2017, China.

Tropospheric ozone (O) is a pollutant of widespread concern in the world and especially in China for its negative effects on agricultural crops. For the first time, yield and economic losses of wheat between 2014 and 2017 were estimated for the North China Plain (NCP) using observational hourly O data from 312 monitoring stations and exposure-response functions based on AOT40 index (accumulated hourly O concentration above 40 ppb) from a Chinese study. AOT40 values from 2014 to 2017 during the wheat growing seasons (75-days, 44 before and 30 after mid-anthesis) ranged from 3.

The ozone sensitivity of five poplar clones is not related to stomatal conductance, constitutive antioxidant levels and morphology of leaves.

Ground-level ozone (O) is an important phytotoxic air pollutant in China. In order to compare the sensitivity of common poplar clones to O in China and explore the possible mechanism, five poplar clones, clone DQ (Populus cathayana), clone 84 K (P. alba × P.

Effects of ozone on maize (Zea mays L.) photosynthetic physiology, biomass and yield components based on exposure- and flux-response relationships.

Since the Industrial Revolution, the global ambient O concentration has more than doubled. Negative impact of O on some common crops such as wheat and soybeans has been widely recognized, but there is relatively little information about maize, the typical C4 plant and third most important crop worldwide. To partly compensate this knowledge gap, the maize cultivar (Zhengdan 958, ZD958) with maximum planting area in China was exposed to a range of chronic ozone (O) exposures in open top chambers (OTCs).

A quantitative assessment of hormetic responses of plants to ozone.

Evaluations of ozone effects on vegetation across the globe over the last seven decades have mostly incorporated exposure levels that were multi-fold the preindustrial concentrations. As such, global risk assessments and derivation of critical levels for protecting plants and food supplies were based on extrapolation from high to low exposure levels. These were developed in an era when it was thought that stress biology is framed around a linear dose-response.

Ozone exposure- and flux-yield response relationships for maize.

A stomatal ozone (O) flux-response relationship for relative yield of maize was established by parameterizing a Jarvis stomatal conductance model. For the function (f) describing the limitation of stomatal conductance by vapor pressure deficit (VPD, kPa), cumulative VPD during daylight hours was superior to hourly VPD. The latter function is proposed as a methodological improvement of this multiplicative model when stomatal conductance peaks during the morning and it is reduced later as it is the case of maize in this experiment.

Current ambient and elevated ozone effects on poplar: A global meta-analysis and response relationships.

The effects of current and future elevated O concentrations (e[O]) were investigated by a meta-analysis for poplar, a widely distributed genus in the Northern Hemisphere with global economic importance. Current [O] has significantly reduced CO assimilation rate (P) by 33% and total biomass by 4% in comparison with low O level (charcoal-filtered air, CF). Relative to CF, an increase in future [O] would further enhance the reduction in total biomass by 24%, plant height by 17% and plant leaf area by 19%.

Predicting the effect of ozone on vegetation via linear non-threshold (LNT), threshold and hormetic dose-response models.

Unlabelled: The nature of the dose-response relationship in the low dose zone and how this concept may be used by regulatory agencies for science-based policy guidance and risk assessment practices are addressed here by using the effects of surface ozone (O) on plants as a key example for dynamic ecosystems sustainability. This paper evaluates the current use of the linear non-threshold (LNT) dose-response model for O. The LNT model has been typically applied in limited field studies which measured damage from high exposures, and used to estimate responses to lower concentrations.

Intraspecific variation in sensitivity of winter wheat (Triticum aestivum L.) to ambient ozone in northern China as assessed by ethylenediurea (EDU).

Wheat is a major staple food and its sensitivity to the gas pollutant ozone (O) depends on the cultivar. However, few chamber-less studies assessed current ambient O effects on a large number of wheat cultivars. In this study, we used ethylenediurea (EDU), an O protectant whose protection mechanisms are still unclear, to test photosynthetic pigments, gas exchange, antioxidants, and yield of 15 cultivars exposed to 17.