Joint optimization of land carbon uptake and albedo can help achieve moderate instantaneous and long-term cooling effects

Both carbon dioxide uptake and albedo of the land surface affect global climate. However, climate change mitigation by increasing carbon uptake can cause a warming trade-off by decreasing albedo, with most research focusing on afforestation and its interaction with snow. Here, we present carbon uptake and albedo observations from 176 globally distributed flux stations. We demonstrate a gradual decline in maximum achievable annual albedo as carbon uptake increases, even within subgroups of non-forest and snow-free ecosystems. Based on a paired-site permutation approach, we quantify the likely impact of land use on carbon uptake and albedo. Shifting to the maximum attainable carbon uptake at each site would likely cause moderate net global warming for the first approximately 20 years, followed by a strong cooling effect. A balanced policy co-optimizing carbon uptake and albedo is possible that avoids warming on any timescale, but results in a weaker long-term cooling effect.Ministry of Education, Youth & Sports - Czech RepublicSustES-Adaptation strategies for sustainable ecosystem services and food securityInstitut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique (CNRS-INSU)University Toulouse IIICentre National D'etudes Spatiales732 IRD (Institut de Recherche pour le Developpement)Swiss National Science Foundation (SNSF)United States Department of Energy (DOE)Estonian Research CouncilAustrian Research Promotion Agency (FFG)Federal Ministry of Education & Research (BMBF) LM2018123German Research Foundation (DFG) CZ.02.1.01/0.0/0.0/16019/0000797Ministry of Lower-Saxony for Science and CultureMCIN/AEI/"ESF Investing in your future"FEDER/Junta de AndaluciaTerrestrial Environmental Observatories, TERENO - Helmholtz-Gemeinschaft, Germany 20F120_198227Russian Science Foundation (RSF) PSG631 PSG714 INST 186/1118-1 FUGG SFB 1502/12022 450058266 ZN 3679 PID2020-117825GB-C21 PID2020-117825GB-C22 B-RNM-60-UGR20 P18-RT-3629 FPU19/01647 21-14-0020

The temporary effect of weed-cover maintenance on transpiration and carbon assimilation of olive trees

The maintenance of spontaneous weed cover is a conservation practice used in olive groves. Herbaceous plants in alleys between the trees can increase the capacity of this agroecosystem to remove carbon. However, the influence of this practice on carbon assimilation at the leaf scale has not yet been studied in olive trees. Also, the presence of other species competing with olive trees for soil water has the potential to modify the water use efficiency, a key parameter in a climate change context. In this study, leaf-scale net carbon assimilation (Aleaf), transpiration (Eleaf) and water use efficiency as the ratio Aleaf/Eleaf(WUEleaf) were quantified in olive grove divided by two different treatments: (1) a weed-free (WF) ecosystem in which weed growth was inhibited by applying herbicide; and (2) a weed-covered (WC) ecosystem in which spontaneous herbaceous plants were kept and then mechanically mowed and left on the ground. A portable leaf photosynthesis system was used to measure olive leaf fluxes for both treatments, and likewise for the ecosystem scale via two eddy covariance towers assessing gross primary production (GPPeco), evapotranspiration (ETeco), and water use efficiency (WUEeco). We found that the average Aleaf was 24% higher in the WF treatment while GPPeco decreased 32% compared to WC treatment. However, Aleaf was significantly different between treatments only during weed growth: January-May (Aleaf-WF = 7.6±3.7 μmol CO2m−2s−1; Aleaf-WC = 5.1±3.1 μmol CO2m−2s−1) while Aleaf was similar between the two treatments after mowing. Mowed weeds decreased Tsoil and VPD, and these changes were accompanied by a decrease in Eleaf in olive trees. Therefore, this led to WUEleaf-WF>WUEleaf-WC when the weeds were growing and the opposite after mowing. Thus, although the presence of spontaneous weeds increased the annual ecosystem C uptake in the olive orchard, both Aleaf and seasonal fluctuations in WUEleaf were reduced with weed maintenance

Modelling actual evapotranspiration using a two source energy balance model with Sentinel imagery in herbaceous-free and herbaceous-cover Mediterranean olive orchards

To the European Space Agency for the imagery of the Sentinel Missions and its open access. Special thanks to Radoslaw Guzinski for share and make accessible (https://github.com/radosuav/pyDMS) the implemented software for the used sharpening process (likewise to Hector Nieto for the implemented TSEB-PT, https://github.com/hectornieto/pyTSEB).To the Group of Castillo de Canena for the use of their farm as an experimental site and their people for continuous cooperation. We also give special thanks to Andrew S. Kowalski for his advice and suggestions. We would like also to express our gratitude to the anonymous reviewers for their comments and suggestions that enhanced this work. This work was supported by the Spanish Ministry of Science and Innovation through project CGL2017-83538-C3-1-R (ELEMENTAL) and PID2020-117825GB-C21 (INTEGRATYON3) Including European Union ERDF funds [grant number PRE2018-085638]. Funding for open access charge: Universidad de Granada/CBUA.Precipitation deficit and more extreme drought and precipitation events are expected to increase in the Mediterranean region due to global warming. A great part of this region is covered by olive orchards, representing 97.5% of the world’s olive agricultural area. Thus, the adaptation of olive cultivation demands climate-smart management, such as the optimization of water use efficiency, since evapotranspiration is one of the most important components of the water balance. The novelty of this work is the combination of the remote sensing data fusion and the Two Source Energy Balance (TSEB) model (through Sentinel-2 and Sentinel-3 imagery) to estimate the actual daily evapotranspiration (ETd), at high spatial (20 m) and temporal (daily) resolution, in an olive orchard under two management regimes: herbaceous free (HF) and herbaceous-cover (HC); along a three years period, based on the hypothesis that TSEB is still able to track and estimate the evapotranspiration over more complex canopies. The study was carried out from 2016 to 2019 in an olive orchard in the South of Spain, where the flux estimates were validated and assessed by in situ eddy covariance (EC) measurements. The results show better agreement in HC for net radiation (Rn) and the soil heat flux (G), but similar for both surfaces regarding the sensible (H) and latent (λE) heat fluxes, as well as ETd. On both surfaces greater differences obtained at higher H, and the magnitude of overestimation of λE and ETd were influenced by the EC energy imbalance. By contrast, G was overestimated with HC probably influenced by herbs, and equally underestimated for HF surfaces. The obtained results are in agreement with similar studies in tree crop orchards, and show the consistency of the used methodology and its usefulness for some farming activities, even on the more heterogeneous surface.Spanish Government CGL2017-83538-C3-1-R PID2020-117825GB-C21European Commission PRE2018-085638Universidad de Granada/CBU

Evapotranspiration prediction for European forest sites does not improve with assimilation of in situ soil water content data

Land surface models (LSMs) are an important tool for advancing our knowledge of the Earth system. LSMs are constantly improved to represent the various terrestrial processes in more detail. High-quality data, freely available from various observation networks, are being used to improve the prediction of terrestrial states and fluxes of water and energy. To optimize LSMs with observations, data assimilation methods and tools have been developed in the past decades.We apply the coupled Community Land Model version 5 (CLM5) and Parallel Data Assimilation Framework (PDAF) system (CLM5-PDAF) for 13 forest field sites throughout Europe covering different climate zones. The goal of this study is to assimilate in situ soil moisture measurements into CLM5 to improve the modeled evapotranspiration fluxes. The modeled fluxes will be evaluated using the predicted evapotranspiration fluxes with eddy covariance (EC) systems. Most of the sites use point-scale measurements from sensors placed in the ground; however, for three of the forest sites we use soil water content data from cosmic-ray neutron sensors, which have a measurement scale closer to the typical land surface model grid scale and EC footprint. Our results show that while data assimilation reduced the root-mean-square error for soil water content on average by 56% to 64 %, the root-mean-square error for the evapotranspiration estimation is increased by 4 %. This finding indicates that only improving the soil water content (SWC) estimation of state-of-the-art LSMs such as CLM5 is not sufficient to improve evapotranspiration estimates for forest sites. To improve evapotranspiration estimates, it is also necessary to consider the representation of leaf area index (LAI) in magnitude and timing, as well as uncertainties in water uptake by roots and vegetation parameters.LIFE programme of the European Union under contract number LIFE 17 CCA/ES/000063, with additional funding from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – SFB 1502/1-2022 – project number 45005826

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements