Components, drivers and temporal dynamics of ecosystem respiration in a Mediterranean pine forest

To investigate the climate impacts on the different components of ecosystem respiration, we combined soil efflux data from a tree-girdling experiment with eddy covariance CO2 fluxes in a Mediterranean maritime pine (Pinus pinaster) forest in Central Italy. 73 trees were stem girdled to stop the flux of photosynthates from the canopy to the roots, and weekly soil respiration surveys were carried out for one year. Heterotrophic respiration (RH) was estimated from the soil CO2 flux measured in girdled plots, and rhizosphere respiration (RAb) was calculated as the difference between respiration from controls (RS) and girdled plots (RH). Results show that the RS dynamics were clearly driven by RH (average RH/RS ratio 0.74). RH predictably responded to environmental variables, being predominantly controlled by soil water availability during the hot and dry growing season (MayeOctober) and by soil temperature during the wetter and colder months (NovembereMarch). High RS and RH peaks were recorded after rain pulses greater than 10 mm on dry soil, indicating that large soil carbon emissions were driven by the rapid microbial oxidation of labile carbon compounds. We also observed a time-lag of one week between water pulses and RAb peaks, which might be due to the delay in the translocation of recently assimilated photosynthates from the canopy to the root system. At the ecosystem scale, total autotrophic respiration (RAt, i.e. the sum of carbon respired by the rhizosphere and aboveground biomass) amounted to 60% of ecosystem respiration. RAt was predominantly controlled by photosynthesis, and showed high temperature sensitivity (Q10) only during the wet periods. Despite the fact that the study coincided with an anomalous dry year and results might therefore not represent a general pattern, these data highlight the complex climatic control of the respiratory processes responsible for ecosystem CO2 emissions. © 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

Seasonal trends and environmental controls of methane emissions in a rice paddy field in Northern Italy

Rice paddy fields are one of the greatest anthropogenic sources of methane (CH4), the third most important greenhouse gas after water vapour and carbon dioxide. In agricultural fields, CH4 is usually measured with the closed chamber technique, resulting in discontinuous series of measurements performed over a limited area, that generally do not provide sufficient information on the short-term variation of the fluxes. On the contrary, aerodynamic techniques have been rarely applied for the measurement of CH4 fluxes in rice paddy fields. The eddy covariance (EC) technique provides integrated continuous measurements over a large area and may increase our understanding of the underlying processes and diurnal and seasonal pattern of CH4 emissions in this ecosystem. For this purpose a Fast Methane Analyzer (Los Gatos Research Ltd.) was installed in a rice paddy field in the Po Valley (Northern Italy). Methane fluxes were measured during the rice growing season with both EC and manually operated closed chambers. Methane fluxes were strongly influenced by the height of the water table, with emissions peaking when it was above 10–12 cm. Soil temperature and the developmental stage of rice plants were also responsible of the seasonal variation on the fluxes. The measured EC fluxes showed a diurnal cycle in the emissions, which was more relevant during the vegetative period, and with CH4 emissions being higher in the late evening, possibly associated with higher water temperature. The comparison between the two measurement techniques shows that greater fluxes are measured with the chambers, especially when higher fluxes are being produced, resulting in 30% higher seasonal estimations with the chambers than with the EC (41.1 and 31.7 gCH4 m−2 measured with chambers and EC respectively) and even greater differences are found if shorter periods with high chamber sampling frequency are compared. The differences may be a result of the combined effect of overestimation with the chambers and of the possible underestimation by the EC technique.JRC.H.7-Climate Risk Managemen

JRC-Ispra Atmosphere - Biosphere - Climate Integrated monitoring Station: 2016 report

A comprehensive set of essential atmospheric variables have been measured at the JRC-Ispra Atmosphere - Biosphere - Climate Integrated monitoring Station (ABC-IS) for several years to assess the impact of European policies and international conventions on air pollution and climate forcing. The variables we measure at the Atmospheric Observatory in Ispra include greenhouse gas concentrations (CO2, CH4, N2O, SF6), radon (222Rn) activity concentration, short-lived gaseous and particulate pollutant (CO, SO2, NO, NO2, O3, PM2.5 and its main ionic and carbonaceous constituents) concentrations, atmospheric particle micro-physical characteristics (number concentration and size distribution) and optical properties (light scattering and absorption in-situ, light scattering and extinction vertical profiles remotely), eutrophying and acidifying species (SO42-, NO3-, NH4+) wet deposition. Vegetation atmosphere exchanges (CO2, O3, H2O and heat) are measured at our Forest Flux Station of San Rossore, backed up by meteorological and pedological measurements. The ABC-IS 2016 report presents the data produced during the past year in the context of the previous years of measurements.JRC.C.5-Air and Climat

JRC – Ispra: Atmosphere – Biosphere – Climate Integrated monitoring Station: 2015 Report

A comprehensive set of essential atmospheric variables have been measured at the JRC-Ispra Atmosphere -Biosphere - Climate Integrated monitoring Station (ABC-IS) for several years to detect the impact of European policies and international conventions on air pollution and climate forcing. The variables we measure include greenhouse gas concentrations (CO2, CH4, N2O, SF6), radon (222Rn)activity concentration, short-lived gaseous and particulate pollutants (CO, SO2, NO, NO2, O3, PM2.5 and its main ionic and carbonaceous constituents), atmospheric particle micro-physical characteristics (number concentration and size distribution) and optical properties (light scattering and absorption in-situ, light scattering and extinction vertical profiles remotely), eutrophying and acidifying species (SO42-, NO3-, NH4+) wet deposition, and vegetation atmosphere exchanges (CO2, O3, H2O and heat), backed up by meteorological and pedological measurements. All the measurements performed at ABC-IS are made under international projects and programs like InGOS (Integrated non-CO2 Greenhouse gas Observation System), ACTRIS (the EU research Infra-Structure for the observation of Aerosols, Clouds and TRace gases), EMEP (co-operative Program for Monitoring and Evaluation of the long range transmission of air pollutants in Europe) and GAW (Global Atmosphere Watch), which implies the use of standard methods and scales, and the participation in quality assurance activities. The JRC has a leading role in ACTRIS and EMEP regarding the quality assurance for carbonaceous aerosol measurements. All the data obtained at ABC-IS are submitted to international open data bases (www.europe-fluxdata.eu, fluxnet.ornl.gov, www.ingos-infrastructure.eu, ebas.nilu.no,) and can be freely downloaded from these web sites. The data we produce are used in European wide assessments, for model inputs and validation, and for calibrating satellite airborne sensors. The ABC-IS 2015 report presents the data produced during the past year in the context of the previous years of measurements.JRC.C.5-Air and Climat

JRC – Ispra Atmosphere – Biosphere – Climate Integrated monitoring Station 2013 report

The Institute for Environment and Sustainability provides long-term observations of the atmosphere within international programs and research projects. These observations are performed from the research infrastructure named ABC-IS: Atmosphere – Biosphere – Climate Integrated monitoring Station. Most measurements are performed at the JRC-Ispra site, but observations are also carried out from two other platforms: the forest station in San Rossore, and a ship cruising in the Western Mediterranean sea. This document reports about the measurement programs, the equipment which is deployed, the data quality assessment, and the results obtained for each site. Our observations are presented, compared to each other, as well as to historical data obtained over more than 25 years at the Ispra site.JRC.H.2-Air and Climat

JRC – Ispra Atmosphere – Biosphere – Climate Integrated monitoring Station: 2014 Report

The Institute for Environment and Sustainability provides long-term observations of the atmosphere within international programs and research projects. These observations are performed from the research infrastructure named ABC-IS: Atmosphere – Biosphere – Climate Integrated monitoring Station. Most measurements are performed at the JRC-Ispra site, but observations are also carried out from two other platforms: the forest station in San Rossore, and a ship cruising in the Western Mediterranean sea. This document reports about the measurement programs, the equipment which is deployed, the data quality assessment, and the results obtained for each site. Our observations are presented, compared to each other, as well as to historical data obtained over close to 30 years at the Ispra site.JRC.H.2-Air and Climat

JRC-Ispra Atmosphere-Biosphere-Climate Integrated monitoring Station 2012 report

The Institute for Environment and Sustainability provide long-term observations of the atmosphere within international programs and research projects. These observations are performed from the research infrastructure named ABC-IS: Atmosphere – Biosphere – Climate Integrated monitoring station. Most measurements are performed at the JRC-Ispra site. Observations are also carried out from two other platforms: the forest station in San Rossore, and a ship cruising in the Western Mediterranean sea. This document reports about measurement programs, the equipment which is deployed, the data quality assessment, and the results obtained for each site. Our observations are presented, compared to each other, as well as to historical data obtained over more than 25 years at the Ispra siteJRC.H.2-Air and Climat

The European Commission Atmospheric Observatory: 2017 Report

A comprehensive set of essential atmospheric variables have been measured since 1986 at the JRC-Ispra site to assess the impact of European policies and international conventions on air pollution and climate forcing. In 2017, all instruments have been moved at the new Atmospheric Observatory. The variables we measure include greenhouse gas concentrations (CO2, CH4, N2O, SF6), radon (222Rn) activity concentration, short-lived gaseous and particulate pollutant (CO, SO2, NO, NO2, O3, PM2.5 and its main ionic and carbonaceous constituents) concentrations, atmospheric particle micro-physical characteristics (number concentration and size distribution) and optical properties (light scattering and absorption in-situ, light scattering and extinction vertical profiles remotely), eutrophying and acidifying species (SO42-, NO3-, NH4+) wet deposition. Atmosphere-biosphere exchange fluxes are measured at the Mediterranean site of San Rossore.JRC.C.5-Air and Climat

The European Commission Atmospheric Observatory

A comprehensive set of essential atmospheric variables have been measured in 2018 at the European Commission Atmospheric Observatory on the site of the historical EMEP-GAW station of the JRC in Ispra to continue the assessment of the impact of European policies and international conventions on air pollution and climate forcing that started in 1985. The variables we measure at the Atmospheric Observatory in Ispra include greenhouse gas concentrations (CO2, CH4), radon (222Rn) activity concentration, short-lived gaseous and particulate pollutant concentrations (CO, SO2, NO, NO2, O3, NMHCs, PM2.5 and its main ionic and carbonaceous constituents), atmospheric particle micro-physical characteristics (number concentration and size distribution) and optical properties (light scattering and absorption in-situ, light scattering and extinction vertical profiles remotely), eutrophying and acidifying species (sulphate, nitrate, ammonium) wet deposition. Vegetation - atmosphere exchanges (CO2, O3, H2O and heat) are measured at our Mediterranean Forest Flux Station of San Rossore, backed up by meteorological and pedological measurements.JRC.C.5-Air and Climat

JRC – Ispra Atmosphere – Biosphere – Climate Integrated monitoring Station : 2011 report

The Institute for Environment and Sustainability provide long-term observations of the atmosphere within international programs and research projects. These observations are performed from the research infrastructure named ABC-IS: Atmosphere-Biosphere-Climate Integrated monitoring station. Most measurements are performed at the JRC-Ispra site. Observations are also carried out from two other platforms: the forest station in San Rossore, and a ship cruising in the Western Mediterranean sea. This document reports about measurement programs, the equipment which is deployed, and the data quality assessment for each site. Our observations are presented, compared to each other, as well as to historical data obtained over the past 25 years at the Ispra site.JRC.H.2-Air and Climat