Structural, ecological and biogeographical attributes of European vegetation alliances

The first comprehensive phytosociological classification of all vegetation types in Europe (EuroVegChecklist; Applied Vegetation Science, 2016, 19, 3–264) contained brief descriptions of each type. However, these descriptions were not standardized and mentioned only the most distinct features of each vegetation type. The practical application of the vegetation classification system could be enhanced if users had the option to select sets of vegetation types based on various combinations of structural, ecological, and biogeographical attributes. Based on a literature review and expert knowledge, we created a new database that assigns standardized categorical attributes of 12 variables to each of the 1106 alliances dominated by vascular plants defined in EuroVegChecklist. These variables include dominant life form, phenological optimum, substrate moisture, substrate reaction, salinity, nutrient status, soil organic matter, vegetation region, elevational vegetation belt, azonality, successional status and naturalness. The new database has the potential to enhance the usefulness of phytosociological classification for researchers and practitioners and to help understand this classification to non-specialists

Distribution maps of vegetation alliances in Europe

Aim: The first comprehensive checklist of European phytosociological alliances, orders and classes (EuroVegChecklist) was published by Mucina et al. (2016, Applied Vegetation Science, 19 (Suppl. 1), 3–264). However, this checklist did not contain detailed information on the distribution of individual vegetation types. Here we provide the first maps of all alliances in Europe. Location: Europe, Greenland, Canary Islands, Madeira, Azores, Cyprus and the Caucasus countries. Methods: We collected data on the occurrence of phytosociological alliances in European countries and regions from literature and vegetation-plot databases. We interpreted and complemented these data using the expert knowledge of an international team of vegetation scientists and matched all the previously reported alliance names and concepts with those of the EuroVegChecklist. We then mapped the occurrence of the EuroVegChecklist alliances in 82 territorial units corresponding to countries, large islands, archipelagos and peninsulas. We subdivided the mainland parts of large or biogeographically heterogeneous countries based on the European biogeographical regions. Specialized alliances of coastal habitats were mapped only for the coastal section of each territorial unit. Results: Distribution maps were prepared for 1,105 alliances of vascular-plant dominated vegetation reported in the EuroVegChecklist. For each territorial unit, three levels of occurrence probability were plotted on the maps: (a) verified occurrence; (b) uncertain occurrence; and (c) absence. The maps of individual alliances were complemented by summary maps of the number of alliances and the alliance–area relationship. Distribution data are also provided in a spreadsheet. Conclusions: The new map series represents the first attempt to characterize the distribution of all vegetation types at the alliance level across Europe. There are still many knowledge gaps, partly due to a lack of data for some regions and partly due to uncertainties in the definition of some alliances. The maps presented here provide a basis for future research aimed at filling these gaps

Proposal of new syntaxa and series of Grey Willow forests of humid dunes slacks of the North-Atlantic coasts of Europe

This article aims to point out the recent emergence of willows within the dune slacks of the Atlantic coasts following land abandonment. Firstly, a new association present in Brittany is examined: the Epipactido palustris – Salicetum atrocinereae ass. nova hoc loco with a detailed description about its physiognomic, floral, and ecological characteristics. Related dynamico-catenal trajectories that follow the expression of those forests are also described. This survey highlights an original littoral forest formation that could constitute the head of a vegetation series. Elements of reflection are proposed as for the conservation of the dune slacks woodlands and should allow the managers to refine their strategies. Secondly, the existence of a similar association along the coasts of the Channel and the North Sea is reported (Hydrocotylo vulgaris – Salicetum cinereae ass. nova). A new alliance (Carici flaccae – Salicion cinereae all. nova) is proposed in order to regroup these Northwest-European willow forests of the dune slacks and to clarify their synsystematic status.</p

Bioclimatic dataset of Metropolitan France under current conditions derived from the WorldClim model

International audienc

Large‐scale and fine‐grained mapping of heathland habitats using open‐source remote sensing data

International audienceGrassland habitats provide many ecosystem services but are threatened by agricultural intensification and urbanization. While the lack of accurate and comprehensive inventories at the national scale makes them difficult to manage, advances in spatial modeling using open remote sensing data and open-source software, as well as the increasing use of ecological archives, provide new perspectives for mapping natural habitats. In this context, this study evaluated the contribution of spectral and environmental variables to discriminate and then map grassland habitats throughout France. To this end, 92 spectral variables derived from moderate-resolution imaging spectroradiometer data, 19 bioclimatic variables derived from WorldClim data, 4 topographic variables derived from the European Union Digital Elevation Model (DEM), and 8 soil variables derived from SoilGrids data were combined at a spatial resolution of 250 m. Reference plots that characterized 6 and 21 grassland ecosystems at European Nature Information System (EUNIS) levels 2 (broad habitats) and 3 (habitats), respectively, were collected from vegetation archives. We first performed descriptive analysis that included habitat description, ordination, and pairwise separability. We then performed predictive analysis of grassland habitats using a cross-validated random forest model that included a spatial constraint. While environmental and spectral variables characterized most grassland habitats well and consistently, some confusion occurred between habitats with similar abiotic conditions. The main grassland habitat types were correctly mapped at EUNIS level 2 ( F1 score = 0.68), but not at EUNIS level 3 ( F1 score = 0.52). In addition, the two variables that contributed most to the model were the near-infrared spectral band in spring and the minimum temperature of the coldest month. The model’s prediction at EUNIS level 2 for mainland France provides the map of grassland habitats at a new spatial scale

Restauration passive des végétations des hauts de falaises littorales de Bretagne: Modélisation des processus de recolonisation.

National audienceLes activités humaines, notamment liées à la fréquentation touristique ont provoqué la dégradation de plusieurs sites de landes et de pelouses de hauts de falaises littorales. Des relevés botaniques de points contacts décrivent la recolonisation passive de la végétation sur 5 sites bretons après la mise en place d'opérations de restauration sur des périodes allant jusqu'à 15 ans. L'analyse de ces données permet de modéliser la dynamique de succession de ces milieux afin d'évaluer leur restauration

La démarche Ellenberg : une alternative simple et robuste à la démarche réglementaire pour la délimitation des zones humides en France métropolitaine

La délimitation des zones humides est un enjeu majeur pour la protection de ces écosystèmes. La démarche réglementaire décrite dans la circulaire du 18 janvier 2010 relative à la délimitation des zones humides présente des imprécisions, et son application requiert une expertise phytosociologique. La démarche basée sur l’indice d’Ellenberg, qui permet de caractériser directement le degré d’humidité d’un relevé à partir de sa composition floristique, n’a jusqu’à présent été utilisée qu’à une échelle locale. Cette étude vise à évaluer l’intérêt d’utiliser l’indice d’humidité d’Ellenberg pour délimiter les zones humides sur l’ensemble des régions biogéographiques et des grands types d’habitats présents en France métropolitaine. Pour cela, 76 284 relevés phytosociologiques archivés dans plusieurs bases de données ont été analysés. Le caractère humide de chaque relevé a d’abord été déterminé selon la démarche réglementaire puis en utilisant l’indice d’Ellenberg. Les résultats montrent une forte corrélation entre les deux approches (variant de 90,6 à 96,3 % selon les régions biogéographiques, et de 82,4 à 99,2 % selon les habitats) pour une valeur d’Ellenberg de 5,7 ± 0,2. Ils confirment que la démarche basée sur l’indice d’humidité d’Ellenberg est une alternative simple et robuste à la démarche réglementaire pour délimiter les zones humides

KM3NeT front-end and readout electronics system: hardware, firmware, and software

he KM3NeT research infrastructure being built at the bottom of the Mediterranean Sea will host water-Cherenkov telescopes for the detection of cosmic neutrinos. The neutrino telescopes will consist of large volume three-dimensional grids of optical modules to detect the Cherenkov light from charged particles produced by neutrino-induced interactions. Each optical module houses 31 3-in. photomultiplier tubes, instrumentation for calibration of the photomultiplier signal and positioning of the optical module, and all associated electronics boards. By design, the total electrical power consumption of an optical module has been capped at seven Watts. We present an overview of the front-end and readout electronics system inside the optical module, which has been designed for a 1-ns synchronization between the clocks of all optical modules in the grid during a life time of at least 20 years

Architecture and performance of the KM3NeT front-end firmware

The KM3NeT infrastructure consists of two deep-sea neutrino telescopes being deployed in the Mediterranean Sea. The telescopes will detect extraterrestrial and atmospheric neutrinos by means of the incident photons induced by the passage of relativistic charged particles through the seawater as a consequence of a neutrino interaction. The telescopes are configured in a three-dimensional grid of digital optical modules, each hosting 31 photomultipliers. The photomultiplier signals produced by the incident Cherenkov photons are converted into digital information consisting of the integrated pulse duration and the time at which it surpasses a chosen threshold. The digitization is done by means of time to digital converters (TDCs) embedded in the field programmable gate array of the central logic board. Subsequently, a state machine formats the acquired data for its transmission to shore. We present the architecture and performance of the front-end firmware consisting of the TDCs and the state machine