Silvano Fares

Italian National Research Council | CNR

The breakdown of plant material fuels soil functioning and biodiversity. Currently, process understanding of global decomposition patterns and the drivers of such patterns are hampered by the lack of coherent large‐scale datasets. We buried 36,000 individual litterbags (tea bags) worldwide and found an overall negative correlation between initial m...

Simulating the carbon-water fluxes at more widely distributed meteorological stations based on the sparsely and unevenly distributed eddy covariance flux stations is needed to accurately understand the carbon-water cycle of terrestrial ecosystems. We established a new framework consisting of machine learning, determination coefficient (R²), Euclide...

Carbon dioxide (CO2) uptake by plant photosynthesis, referred to as gross primary production (GPP) at the ecosystem level, is sensitive to environmental factors, including pollutant exposure, pollutant uptake, and changes in the scattering of solar shortwave irradiance (SWin) - the energy source for photosynthesis. The 2020 spring lockdown due to C...

This introductory chapter will evaluate how we have reached the current point in the history of world urbanity, its relationship with nature, and why a fusion between the two is now necessary. In order to define BioCities as cities which follow the principles of natural ecosystems to promote life, we will refer to the extensive knowledge of the his...

Fundamental axes of variation in plant traits result from trade-offs between costs and benefits of resource-use strategies at the leaf scale. However, it is unclear whether similar trade-offs propagate to the ecosystem level. Here, we test whether trait correlation patterns predicted by three well-known leaf- and plant-level coordination theories –...

Il presente documento sintetizza i contenuti e gli orientamenti essenziali del progetto di ricerca EUFORICC per proporre modelli, programmi, metodi e protocolli metodologici volti a sostenere la pianificazione, la gestione e la progettazione del verde urbano, mediante l’adozione di soluzioni basate sulla natura, con particolare riferimento agli alb...

Durante lo svolgimento del progetto PRIN EUFORICC (Establishing Urban FORest based solutions In Changing Cities), le numerose ricerche compiute in concerto tra le sei unità di ricerca afferenti al progetto hanno contribuito ad individuare una lista di indicatori per il monitoraggio e la gestione delle foreste urbane. Il monitoraggio delle sfide soc...

Esiti del progetto PRIN EUFORICC - Establishing Urban FORest based solutions In Changing Cities: a) Linee Guida - Esperienze di ricerca e indicazioni operative dedicate alla realtà degli ambienti urbani italiani e mediterranei per la realizzazione, manutenzione e riqualificazione di foreste urbane e infrastrutture verdi. b) Indicatori - Indicatori...

While the eddy covariance (EC) technique is a well-established method for measuring water fluxes (i.e., evaporation or 'evapotranspiration', ET), the measurement is susceptible to many uncertainties. One such issue is the potential underestimation of ET when relative humidity (RH) is high (>70%), due to low-pass filtering with some EC systems. Yet,...

In order to maximize ecosystem services (ES), a proper planning of urban green areas is needed. In this study, the urban greenery of two Italian cities (Milan and Bologna) exposed to high levels of atmospheric pollutants was examined. Vegetation maps were developed through a supervised classification algorithm, trained over remote sensing images, i...

Ecosystem services delivered by natural ecosystems are increasingly important for climate change adaptation and mitigation and play a huge role in biodiversity conservation. For this reason, the EU has the ambitious goal of protecting at least 30% of land by 2030. Member states are called to improve and expand the network of protected areas within...

Nature based solutions (NBS) have been put forward as an effective approach for improving human well-being in the cities during the last decade and many of them make use of vegetation (trees, grass, etc.). The role of vegetation in regulating air temperature and moisture availability is recognized together with its capacity to remove pollutants. Ye...

Biogenic Volatile Organic Compounds (BVOCs) emitted from vegetation are precursors of ozone (O3), photochemical oxidants and secondary organic aerosols (SOA) in the lower troposphere. The interaction between urban polluted air plumes originated along the coasts of the Mediterranean basin with biogenic emission occurring inland contributes to the oc...

Fundamental axes of variation in plant traits result from trade-offs between costs and benefits of resource-use strategies at the leaf scale. However, it is unclear whether trade-offs and optimality principles in functional traits of leaves are conserved at the ecosystem level. We tested three well-known leaf- and plant-level coordination theories...

The cover image is based on the Original Article Cell wall ester modifications and volatile emission signatures of plant response to abiotic stress by Kolby J. Jardine et al., https://doi.org/10.1111/pce.14464.

Growth suppression and defense signaling are simultaneous strategies that plants invoke to respond to abiotic stress. Here, we show that the drought stress response of poplar trees (Populus trichocarpa) is initiated by a suppression in cell wall derived methanol (MeOH) emissions and activation of acetic acid (AA) fermentation defenses. Temperature...

Growth suppression and defense signaling are simultaneous strategies that plants invoke to respond to abiotic stress. Here, we show that the drought stress response of poplar trees ( Populus trichocarpa ) is initiated by a suppression in cell wall derived methanol (MeOH) emissions and activation of acetic acid (AA) fermentation defenses. Temperatur...

Mediterranean coastal areas are among the most threated forest ecosystems in the northern hemisphere due to concurrent biotic and abiotic stresses. These may affect plants functionality and, consequently, their capacity to provide ecosystem services. In this study, we integrated ground-level and satellite-level measurements to estimate the capacity...

Nature-based solutions and green urban infrastructures are becoming common measures in local air quality and climate strategies. However, there is a lack of analytical frameworks to anticipate the effect of such interventions on urban meteorology and air quality at a city scale. We present a modelling methodology that relies on the weather research...

Dry deposition could partially explain the observed response in ambient ozone to extreme hot and dry episodes. We examine the response of ozone deposition to heat and dry anomalies using three long‐term co‐located ecosystem‐scale carbon dioxide, water vapor and ozone flux measurement records. We find that, as expected, canopy stomatal conductance g...

Stomatal O3 flux accumulated over the growing season (or phytotoxic ozone dose above a y threshold of uptake, PODy) is nowadays considered as the best biologically based metric to assess O3 injury to vegetation and establishing critical levels (CLs). So far, CLs have used biomass losses as forest-health indicator in experimental research. Ozone-ind...

Growth suppression and defense signaling are simultaneous strategies that plants invoke to respond to abiotic stress. Here, we show that the drought stress response of poplar trees ( Populus trichocarpa ) is initiated by a suppression in cell wall derived methanol (meOH) emissions and activation of acetic acid (AA) fermentation defenses. Temperatur...

La lecceta di Castelporziano: un sito internazionale per comprendere risposte ecofisiologiche ai cambiamenti climatici Abstract-The holm oak Forest of Castelporziano: an international site to study ecophys-iological responses to climate changes. By hosting a forest of about 6000 hectares a few kilometers from the city of Rome, the Castelporziano Pr...

At forest sites, phytotoxic tropospheric ozone (O3) can be monitored with continuously operating, active monitors (AM) or passive, cumulative samplers (PM). For the first time, we present evidence that the sustainability of active monitoring is better than that of passive sensors, as the environmental, economic, and social costs are usually lower i...

The role of stomata in regulating photosynthesis and transpiration, and hence governing global biogeochemical cycles and climate, is well‐known. Less well‐understood, however, is the importance of stomatal control to the exchange of other trace gases between terrestrial vegetation and the atmosphere. Yet these gases determine atmospheric compositio...

Tropospheric ozone is a dangerous atmospheric pollutant for forest ecosystems when it penetrates stomata. Thresholds for ozone-risk assessment are based on accumulated stomatal ozone fluxes such as the Phytotoxic Ozone Dose (POD). In order to identify the effect of ozone on a Holm oak forest in central Italy, four flux-based ozone impact response f...

Leaf area index (LAI) is a key ecological indicator for describing the structure of canopies and for modelling energy exchange between atmosphere and biosphere. While LAI of the forest overstory can be accurately assessed over large spatial scales via remote sensing, LAI of the forest understory (LAI u) is still largely ignored in ecological studie...

Large datasets of greenhouse gas and energy surface-atmosphere fluxes measured with the eddy-covariance technique (e.g., FLUXNET2015, AmeriFlux BASE) are widely used to benchmark models and remote-sensing products. This study addresses one of the major challenges facing model-data integration: To what spatial extent do flux measurements taken at in...

Warming-induced carbon loss through terrestrial ecosystem respiration ( Re ) is likely getting stronger in high latitudes and cold regions because of the more rapid warming and higher temperature sensitivity of Re ( Q 10 ). However, it is not known whether the spatial relationship between Q 10 and temperature also holds temporally under a future wa...

p>The following authors were omitted from the original version of this Data Descriptor: Markus Reichstein and Nicolas Vuichard. Both contributed to the code development and N. Vuichard contributed to the processing of the ERA-Interim data downscaling. Furthermore, the contribution of the co-author Frank Tiedemann was re-evaluated relative to the co...

Editorial on the Research Topic 'Interactions between Ozone Pollution and Forest Ecosystems'. This Research Topic of Frontiers in Forests and Global Change, Interactions between Ozone Pollution and Forest Ecosystems, presents eight original research articles that span the field of O3 research on forests and give new insights based on novel results,...

Information about forest background reflectance is needed for accurate biophysical parameter retrieval from forest canopies (overstory) with remote sensing. Separating under- and overstory signals would enable more accurate modeling of forest carbon and energy fluxes. We retrieved values of the normalized difference vegetation index (NDVI) of the f...

Dry deposition to vegetation is a major sink of ground-level ozone and is responsible for about 20 % of the total tropospheric ozone loss. Its parameterization in atmospheric chemistry models represents a significant source of uncertainty for the global tropospheric ozone budget and might account for the mismatch with observations. The model used i...

In the Original publication of the article, the authors found an error in the text “We recommend CLef of 5 and 12 mmol m−2 POD1 for broadleaved species and conifers, respectively” under the section abstract and conclusion

Tropospheric ozone (O3) impairs physiological processes of plants while nitrogen (N) deposition may cause imbalances in soil N and other nutrients such as phosphorus (P) suggesting an increase of P demand for plants. However, the combined effect of O3, soil N and P on isoprene emission from leaves has never been tested. We therefore examined isopre...

Cities are responsible for more than 80% of global greenhouse gas emissions. Sequestration of air pollutants is one of the main ecosystem services that urban forests provide to the citizens. The atmospheric concentration of several pollutants such as carbon dioxide (CO 2), tropospheric ozone (O 3), and particulate matter (PM) can be reduced by urba...

According to projects and practices that the Italian botanists and ecologists are carrying out for bringing “more nature in the city”, new insights for a factual integration between ecological perspectives and more consolidated aesthetic and agronomic approaches to the sustainable planning and management of urban green areas are provided.

Riassunto L'infrastruttura verde incorporata nella pianificazione del territorio contribuisce al conseguimento dell'obiettivo 3.2 della Strategia europea della Biodiversità 2020 "preservare e valorizzare gli ecosistemi e i loro servizi". Inoltre, la Strategia Nazionale del Verde Pubblico (MATTM, 2018) introduce la necessità di ridurre il rischio al...

Rising ozone (O3) concentrations, coupled with an increase in drought frequency due to climate change, pose a threat to plant growth and productivity which could negatively affect carbon sequestration capacity of Northern Hemisphere forests. Using long‐term observations of O3 mixing ratios and soil water content, we implemented empirical drought an...

Drought and heat events, such as the 2018 European drought, interact with the exchange of energy between the land surface and the atmosphere, potentially affecting albedo, sensible and latent heat fluxes, as well as CO 2 exchange. Each of these quantities may aggravate or mitigate the drought, heat, their side effects on productivity, water scarcit...

In summer 2018, Europe experienced a record drought, but it remains unknown how the drought affected ecosystem carbon dynamics. Using observations from 34 eddy covariance sites in different biomes across Europe, we studied the sensitivity of gross primary productivity (GPP) to environmental drivers during the summer drought of 2018 versus the refer...

The European MOTTLES project set-up a new-generation network for ozone (O3) monitoring in 17 plots in France, Italy and Romania. These monitoring stations allowed: (1) estimating the accumulated exposure AOT40 and stomatal O3 fluxes (PODY) with an hourly threshold of uptake (Y) to represent the detoxification capacity of trees (POD1, with Y = 1 nmo...

The FLUXNET2015 dataset provides ecosystem-scale data on CO2, water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their...

The FLUXNET2015 dataset provides ecosystem-scale data on CO2, water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their...

Dry deposition to vegetation is a major sink of ground-level ozone and is responsible for about 20 % of the total tropospheric ozone loss. Its parametrisation in atmospheric chemistry models represent a significant source of uncertainty for the global tropospheric ozone budget and might account for the mismatch with observations. The model used in...

In these days, the role that fine particles in urban areas could play in facilitating the pandemic spread of the COVID-19 virus is becoming increasingly important. It is also well known that exposure to air pollution and in particular to fine dust favors diseases involving the respiratory system. In this context of strong concern, we argue that urb...

Identifying the contributions of chemistry and transport to observed ozone pollution using regional‐to‐global models relies on accurate representation of ozone dry deposition. We use a recently developed configuration of the NOAA GFDL chemistry‐climate model—in which the atmosphere and land are coupled through dry deposition—to investigate the infl...

Tropospheric ozone (O3) is probably the air pollutant most damaging to vegetation. Understanding how plants respond to O3 pollution under different climate conditions is of central importance for predicting the interactions between climate change, ozone impact and vegetation. This work analyses the effect of O3 fluxes on net ecosystem productivity...

Dry deposition of ozone is an important sink of ozone in near‐surface air. When dry deposition occurs through plant stomata, ozone can injure the plant, altering water and carbon cycling and reducing crop yields. Quantifying both stomatal and nonstomatal uptake accurately is relevant for understanding ozone's impact on human health as an air pollut...

Both ozone (O3) and drought can limit carbon fixation by forest trees. To cope with drought stress, plants have isohydric or anisohydric water use strategies. Ozone enters plant tissues through stomata. Therefore, stomatal closure can be interpreted as avoidance to O3 stress. Here we applied an optimization model of stomata involving water, CO2 and...

The response of ozone (O3) dry deposition to ecosystem‐atmosphere interactions is poorly understood but is central to determining the potential for extreme pollution events under current and future climate conditions. Using observations and an interactive dry deposition scheme within two dynamic vegetation land models (Geophysical Fluid Dynamics La...

REVIEW Tropospheric ozone (O3) is one of the most prominent air pollution problems in Europe and other countries worldwide. Human health is affected by O3 via the respiratory as well the cardiovascular systems. Even though trees are present in relatively low numbers in urban areas, they can be a dominant factor in the regulation urban O3 concentrat...

The European beech (Fagus sylvatica L.) is a widely distributed tree species across Europe, highly sensitive to climate change and global warming. This study illustrates results of a 5-year monitoring time period from eight sites of the ICP-Forests Level II (intensive monitoring network) along the Italian latitudinal gradient. The tree-level relati...

In order to understand the main driving factors of ozone (O3) deposition we tested the hypothesis that sky conditions (cloudy, partly cloudy, and clear sky) modulate O3 flux in forest ecosystems via stomatal regulation. The hypothesis is based on the fact that complex microclimate conditions under cloudy sky usually stimulate stomatal conductance....

Atmospheric pollution produced by anthropogenic activities has detrimental effects on humans but also on plants. When forests are affected by exposure to pollutants such as nitrogen oxides, particles (with size ≤ 10 µm), and ozone, they in turn act as sentinels towards pollutant emission and at the same time provide ecosystem services when they sca...

High ozone (O3) pollution impairs the carbon and water balance of trees, which is of special interest in planted forests. However, the effect of long-term O3 exposure on tree growth and water use, little remains known. In this study, we analysed the relationships of intra-annual stem growth pattern, seasonal sap flow dynamics and xylem morphology t...

In the Mediterranean region, ecosystems are severely affected by climate variability. The Italian Peninsula is a hot spot for biodiversity thanks to its heterogeneous landscape and the Mediterranean, Continental, and Alpine climates hosting a broad range of plant functional types along a limited latitudinal range from 40′ to 46′ N. In this study we...