Defoliation, Recovery and Increasing Mortality in Italian Forests: Levels, Patterns and Possible Consequences for Forest Multifunctionality

Forest health and multifunctionality are threatened by global challenges such as climate change. Forest health is currently assessed within the pan-European ICP Forests (International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests) programme through the evaluation of tree crown conditions (defoliation). This paper analyses the results of a 24-year assessment carried out in Italy on 253 permanent plots distributed across the whole forested area. The results evidenced a substantial stability of crown conditions at the national level, according to the usual defoliation thresholds Defoliation > 25% and Defoliation > 60%, albeit with species-specific patterns. Within this apparent temporal stability, an increased fraction of extremely defoliated and dead trees was observed. Extreme defoliation mostly occurred in years with severe summer drought, whereas mortality was higher in the years after the drought. The results for singular species evidenced critical conditions for Castanea sativa Mill. and Pinus species, whereas Quercus species showed a progressive decrease in defoliation. Deciduous species, such as Fagus sylvatica L., Ostrya carpinifolia Scop. and Quercus pubescens Willd. suffer the loss of leaves in dry years as a strategy to limit water loss by transpiration but recover their crown in the following years. The recurrence of extreme heat waves and drought from the beginning of the XXI century may increase the vulnerability of forests, and increased tree mortality can be expected in the future

Plant invasions in Italy: An integrative approach using the European LifeWatch infrastructure database

By using the LifeWatch database – a European e-science infrastructure on native and alien plant occurrence collected from a wide set of Italian terrestrial sites – we estimated the occurrence of alien species in a crosshabitat framework in relation to propagule pressure (P), abiotic (A) and biotic (B) conditions. The research represents an example of macro-ecological assessment of invasion risk at national scale claimed by the recent European regulation (EU 1143/2014) on invasive alien species. Based on a large vegetation dataset, we estimated alien and native species richness across a set of 19 Italian terrestrial sites. By using a Generalized Linear Mixed Model, we investigated the relationship between the proportion of alien occurrence across sites and habitat types (EUNIS) at family level with PAB putative drivers derived from LifeWatch and other open access geographic databases. Our results support the full model as the best-fitting option, highlighting that plant invasion in the Italian terrestrial ecosystems is a function of the combination of PAB conditions. In the first step of the invasion process, the accessibility time from towns plays a major role. By contrast, the abiotic filter imposed by environmental condition (high temperatures and low precipitations) as well the competition with the native community (high species richness) may pose a limit to the settlement and spread of alien species. Because of the high availability of similar data on PAB conditions worldwide, this study represents an effective and easy tool to design appropriate biodiversity conservation policies focused on the prevention of alien spread

Plant invasions in Italy: An integrative approach using the European LifeWatch infrastructure database

By using the LifeWatch database – a European e-science infrastructure on native and alien plant occurrence collected from a wide set of Italian terrestrial sites – we estimated the occurrence of alien species in a crosshabitat framework in relation to propagule pressure (P), abiotic (A) and biotic (B) conditions. The research represents an example of macro-ecological assessment of invasion risk at national scale claimed by the recent European regulation (EU 1143/2014) on invasive alien species. Based on a large vegetation dataset, we estimated alien and native species richness across a set of 19 Italian terrestrial sites. By using a Generalized Linear Mixed Model, we investigated the relationship between the proportion of alien occurrence across sites and habitat types (EUNIS) at family level with PAB putative drivers derived from LifeWatch and other open access geographic databases. Our results support the full model as the best-fitting option, highlighting that plant invasion in the Italian terrestrial ecosystems is a function of the combination of PAB conditions. In the first step of the invasion process, the accessibility time from towns plays a major role. By contrast, the abiotic filter imposed by environmental condition (high temperatures and low precipitations) as well the competition with the native community (high species richness) may pose a limit to the settlement and spread of alien species. Because of the high availability of similar data on PAB conditions worldwide, this study represents an effective and easy tool to design appropriate biodiversity conservation policies focused on the prevention of alien spread

ENUBET: A monitored neutrino beam for high precision cross section measurements

International audienceThe main source of systematic uncertainty on neutrino cross section measurements at the GeV scale is represented by the poor knowledge of the initial flux. The goal of cutting down this uncertainty to 1% can be achieved through the monitoring of charged leptons produced in association with neutrinos, by properly instrumenting the decay region of a conventional narrow-band neutrino beam. Large angle muons and positrons from kaons are measured by a sampling calorimeter on the decay tunnel walls (tagger), while muon stations after the hadron dump can be used to monitor the neutrino component from pion decays. This instrumentation can provide a full control on both the muon and electron neutrino fluxes at all energies. Furthermore, the narrow momentum width (<10%) of the beam provides a O(10%) measurement of the neutrino energy on an event by event basis, thanks to its correlation with the radial position of the interaction at the neutrino detector. The ENUBET project has been funded by the ERC in 2016 to prove the feasibility of such a monitored neutrino beam and is cast in the framework of the CERN neutrino platform (NP06) and the Physics Beyond Colliders initiative. In our contribution, we summarize the ENUBET design, physics performance and opportunities for its implementation in a timescale comparable with next long baseline neutrino experiments

Lepton reconstruction in the ENUBET tagger

The ENUBET project aims at demonstrating the feasibility of a monitored neutrino beam in which the measurement of associated charged leptons in the instrumented decay region of a conventional beam is used to constrain the neutrino flux to unprecedented precision ($\mathcal{O}$(1\%)). Large angle muons and positrons from kaon decays are detected on the decay tunnel walls equipped with a sampling calorimeter with longitudinal, radial and azimuthal segmentation. After a brief description of the ENUBET beamline and of the detectors employed in the lepton tagger, the analysis chain for the event reconstruction, the background suppression and the identification of positrons and muons will be described

High precision measurements of neutrino fluxes with ENUBET

Neutrino fluxes are currently affected by large normalization uncertainties (5-10%). Neutrino physics will require measurements of absolute neutrino cross sections at the GeV scale with exquisite (1%) precision in the near future. For this reason a reduction of the present uncertainties by one order of magnitude would be highly beneficial. This goal might be achieved by producing a sign and momentum selected narrow band beam and monitoring the production of $e^{+}$ in the decay tunnel from the decays of charged Kaons ($K_{e3}$ channel). This technique, which requires a special instrumented beam-line, would allow a 1% level measurement of the cross-sections of the neutrino species ($\nu_e$ and $\bar{\nu}_e$) which are the final states involved in the searches for CP violation with muon neutrino beams at long-baseline. The ENUBET Horizon-2020 ERC Consolidator Grant, approved by the European Research Council in 2015, is the framework within which such a non conventional beam-line will be developed. We present a progress report of the project (2016-2021) after about one year of work, the experimental results on ultra-compact calorimeters suited for the instrumenting the decay tunnel and the R&D in the design of the hadronic beamline

Constraints on the KS0→μ+μ−K^0_S \rightarrow \mu^+ \mu^- Branching Fraction

International audienceA search for the decay KS0→μ+μ- is performed using proton-proton collision data, corresponding to an integrated luminosity of 5.6  fb-1 and collected with the LHCb experiment during 2016, 2017, and 2018 at a center-of-mass energy of 13 TeV. The observed signal yield is consistent with zero, yielding an upper limit of B(KS0→μ+μ-)<2.2×10-10 at 90% C.L.. The limit reduces to B(KS0→μ+μ-)<2.1×10-10 at 90% C.L. once combined with the result from data taken in 2011 and 2012