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Droughts can strongly affect grassland productivity and biodiversity, but responses differ widely. Nutrient availability may be a critical factor explaining this variation, but is often ignored in analyses of drought responses. Here, we used a standardized nutrient addition experiment covering 10 European grasslands to test if full‐factorial nitrogen, phosphorus, and potassium addition affected plant community responses to inter‐annual variation in drought stress and to the extreme summer drought of 2018 in Europe. We found that nutrient addition amplified detrimental drought effects on community aboveground biomass production. Drought effects also differed between functional groups, with a negative effect on graminoid but not forb biomass production. Our results imply that eutrophication in grasslands, which promotes dominance of drought‐sensitive graminoids over forbs, amplifies detrimental drought effects. In terms of climate change adaptation, agricultural management would benefit from taking into account differential drought impacts on fertilized versus unfertilized grasslands, which differ in ecosystem services they provide to society. [ABSTRACT FROM AUTHOR]

Polyporous fungi, a morphologically delineated group of Agaricomycetes (Basidiomycota), are considered well studied in Europe and used as model group in ecological studies and for conservation. Such broad interest, including widespread sampling and DNA based taxonomic revisions, is rapidly transforming our basic understanding of polypore diversity and natural history. We integrated over 40,000 historical and modern records of polypores in Estonia (hemiboreal Europe), revealing 227 species, and including Polyporus submelanopus and P. ulleungus as novelties for Europe. Taxonomic and conservation problems were distinguished for 13 unresolved subgroups. The estimated species pool exceeds 260 species in Estonia, including at least 20 likely undescribed species (here documented as distinct DNA lineages related to accepted species in, e.g., Ceriporia, Coltricia, Physisporinus, Sidera and Sistotrema). Four broad ecological patterns are described: (1) polypore assemblage organization in natural forests follows major soil and tree-composition gradients; (2) landscape-scale polypore diversity homogenizes due to draining of peatland forests and reduction of nemoral broad-leaved trees (wooded meadows and parks buffer the latter); (3) species having parasitic or brown-rot life-strategies are more substratespecific; and (4) assemblage differences among woody substrates reveal habitat management priorities. Our update reveals extensive overlap of polypore biota throughout North Europe. We estimate that in Estonia, the biota experienced ca. 3-5% species turnover during the twentieth century, but exotic species remain rare and have not attained key functions in natural ecosystems. We encourage new regional syntheses on long studied fungal groups to obtain landscape-scale understanding of species pools, and for elaborating fungal indicators for biodiversity assessments. [ABSTRACT FROM AUTHOR]

Aims: The nutrient concentration in herbage and biomass productivity analyses are dependent on the vertical distribution of different sward layers where the sampling is done. Notably, a majority of studies indicate clipping biomass to the ground level without any consideration of the vertical distribution. This study examined the effect of cutting and grazing intensities on the vertical distribution of plant functional groups. Location: Oldřichov Grazing Experiment, northern Czechia. Methods: During a 15‐year experiment: (a) intensive and (b) extensive grazing without cutting; (c) cutting in June followed by intensive and (d) extensive grazing; and (e) undefoliated treatment were applied throughout the vegetation season. Biomass data were collected at two layers in the sward (below and above 3 cm) and separated into five functional groups. Biomass data were analysed to examine the succession and effects of treatments on vertical distribution of functional groups. Results: Treatment effects were differentiated after 2–3 years from the introduction of management, but the composition of functional groups fluctuated over time. Treatments significantly affected total biomass of all functional groups and the vertical distribution within swards of most groups. Particularly intensive grazing significantly decreased the total biomass of graminoids, forbs, and dead biomass in favour of legumes (which increased). This led to a shift in the relative biomass distribution from the upper sward layer to the lower layer for most functional groups except for legumes and mosses. Conclusion: The high proportion of dead biomass in the lower sward layer suggests the need for a methodological approach that considers clipping of biomass only above 3 cm when sampling for productivity and forage quality analysis. This approach would avoid including biomass from below 3 cm or the lower layer, which would be ungrazed by cattle. Many previous studies may have reported a distorted or inflated value in herbage productivity or forage quality results. [ABSTRACT FROM AUTHOR]

Nitrate‐ester based propellants require stabilisers in order to maintain good chemical stability and to prevent oxidation, chain scission, energy loss and uncontrolled heat generation that are caused by homolytic and heterolytic cleavage of the weakest nitrogen‐oxygen bond of the nitrate ester functional group. With REACH legislation (1907/2006), industry in Europe has made progress in using less toxic compounds, that are often more environmentally‐friendly. This work aims to go beyond REACH and to anticipate the inclusion of other molecules that produce non‐ or less toxic daughter products and that can fulfil their role in the propellant's formulation. This paper is the follow‐up to a first paper, presenting six families of "green" stabilisers, which are novel, environmentally friendly, efficient and readily available for use in nitrocellulose‐based compositions. In this article we present the validated lower temperature shelf life predictions for propellants containing the new stabilisers, using heat flow calorimetry (HFC). It will be necessary to modify AOP48 in the near future to be able to include these new stabilisers that provide much better performances than conventional ones (longer shelf lives of propellants) and are also respectful of the environment and human health. [ABSTRACT FROM AUTHOR]

Aims: To create a comprehensive, consistent and unequivocal phytosociological classification of European marsh vegetation of the class Phragmito‐Magnocaricetea. Location: Europe. Methods: We applied the Cocktail method to a European data set of 249,800 vegetation plots. We identified the main purposes and attributes on which to base the classification, defined assignment rules for vegetation plots, and prepared formal definitions for all the associations, alliances and orders of the class Phragmito‐Magnocaricetea using formal logic. Each formula consists of the combination of "functional species groups", cover values of individual species, and in the case of high‐rank syntaxa also of "discriminating species groups" created using the Group Improvement (GRIMP) method. Results: The European Phragmito‐Magnocaricetea vegetation was classified into 92 associations grouped in 11 alliances and six orders. New syntaxa (previously invalidly published according to the International Code of Phytosociological Nomenclature) were introduced: Bolboschoeno maritimi‐Schoenoplection tabernaemontani, Glycerio maximae‐Sietum latifolii, Glycerio notatae‐Veronicetum beccabungae, Schoenoplectetum corymbosi and Thelypterido palustris‐Caricetum elongatae. Based on a critical revision, some other syntaxa were rejected or excluded from the class Phragmito‐Magnocaricetea. Conclusions: This work provides the first consistent classification of the class Phragmito‐Magnocaricetea at the European scale, which is an important tool for nature conservation. Our classification largely respects previously existing concepts of syntaxa, but it also proposes modifications to the recently published EuroVegChecklist. This work also provides a protocol that can be used for extending the current classification to new syntaxa and geographical regions. [ABSTRACT FROM AUTHOR]

The diversity of the fungal community associated with adults of Dryocosmus kuriphilus following emergence was examined using HTS analysis. Ascomycota dominated the fungal core-biome community. The functional guilds of the 90 taxa forming the core-biome were assessed, demonstrating three main groups: saprotrophs, plant pathogens and entomopathogens. Twenty-nine OTUs out of 90 were resolved to species level identifying 26 different fungal species. Among these species, many were cosmopolitan or previously recorded in Europe. Ten taxa were previously recorded on chestnut, including some recognized plant pathogens associated with foliage and green tissues such as Epicoccum nigrum , Gnomoniopsis castanea , Colletotrichum acutatum , Stromatoseptoria castaneicola , Ramularia endophylla. Beauveria bassiana ; within the core microbiome, Fusarium larvarum represented the most abundant entomopathogenic species. Some of these species are known to impact directly or indirectly the vitality of the insects in the galls. The chestnut blight pathogen, Cryphonectria parasitica , was never found associated with D. kuriphilus. Based on the present study, an active role for D. kuriphilus as a vector of chestnut fungal endophyte/pathogens cannot be demonstrated but neither ruled out. [ABSTRACT FROM AUTHOR]

There are several tunnelling projects underway in Europe and worldwide to facilitate connections between distant areas or ones with geographical constraints (e.g. mountains). As a result, the tunnel industry has been producing huge amounts of excavated material (spoil material: SM), which can be re-used for different purposes (including green areas). Adding lime can be a practical procedure at a construction site for the stabilization of SM and makes it possible to manage it better at its final destination site. This work reports a nature-based solution (NBS) for decreasing the highly basic pH (12.53 ± 0.01) of the SM after adding lime, using three different organic fertilizers which are by-products of local olive oil (pomace), compost and digestate production. For this purpose, microcosm experiments were performed with SM amended with compost, pomace or digestate. Half of the microcosms were also seeded with Medicago sativa to evaluate its growth in terms of biomass. The changes in pH and in the structure and functional potential of the microbial community were evaluated in the amended SM at the start and end (4 months) of the experiment. Aerial and root plant biomass and concentrations of leaf chlorophyll and total phenolic compounds were also measured. The microbial biodiversity was evaluated using amplicon sequencing (16S rRNA gene) and a predictive functional analysis was performed by processing sequencing data with the PICRUSt2 tool. Adding the amendments to SM significantly decreased the pH values by 4 units and introduced organic carbon, nitrogen, and active microbial populations. Although pomace promoted the lowest pH decrease (7.98 ± 0.18) and the highest microbial abundance and activity, it did not favour the highest plant growth. Adding compost and digestate to SM can be considered the best NBS for decreasing pH and supporting plant development. M. sativa did not have any direct effect on lowering pH, demonstrating in this study the key role of microorganisms in responding efficiently to this environmental stress and mitigating it. In accordance with these results, predicted bacterial genes coding for membrane proteins (nuo , mrp) and for indoleacetic acid metabolism (ami , nthA , ipdC) involved in pH regulation were identified among the microbial populations. [Display omitted] • Organic amendments introduced active microorganisms in alkaline spoil material. • Microbial populations showed homeostatic responses vs basic pH. • Bacterial groups and predicted functional genes were identified. • Compost and digestate favoured significantly pH decrease and plant growth. • Plant presence did not favour any further pH decrease. [ABSTRACT FROM AUTHOR]

• The process of selecting traits for estimating functional diversity is unclear. • Most of the estimations focused on lotic waters in Europe. • About 80% of the studies used no more than 12 traits. • Traits are suggested to be evenly distributed in four major trait groups. The rapid and continuous loss of biodiversity highlights the urgent need for research on functional diversity. Although the study of functional diversity has exploded in the past two decades, there is no clear guidance on how traits should be selected for index calculation, which significantly influences functional diversity results. To fill this gap, we explored how the functional diversity of freshwater macroinvertebrates has been estimated over the past 20 years and how it differs across continents and water bodies. We found that Europe is the absolute centre of research in this area and that most of the research comes from studies of European lotic waters. By fitting cumulative frequencies to the number of articles using different numbers of traits, our results showed that approximately 80% of the studies used no more than 12 traits to estimate functional diversity. Furthermore, by exploring the use frequency of numbers and types of traits in different regions and water bodies and combining them with trait grouping, we recommend the use of traits evenly from four trait groups to calculate functional diversity indices. This selection strategy can contribute to the unification of functional diversity estimations and comparative studies of different regions, thus helping to better understand and manage biodiversity loss worldwide. [ABSTRACT FROM AUTHOR]

Seven earthworm ecological categories, including anecics, endogeics and epigeics, were defined by Marcel Bouché in 1972 based only on morpho-anatomical characteristics measured on European lumbricids. These categories had an outstanding success, and their use was generalized even outside of Europe. However, most of the time, only the three main categories are used, and over two decades, these categories have been considered functional groups, i.e. to presume how earthworms influence the soil functioning. Moreover, this relationship between ecological categories and functional groups is seldom tested and often uncritically accepted by soil biology researchers. It is then not surprising to observe unexpected trends when earthworm species are gathered in ecological categories to, for instance, analyze burrow systems or cast properties. We believe it is time to acknowledge that ecological categories are not functional, because they were not made for this purpose. We also propose three future directions in order to either improve our knowledge on the functional effects of earthworms or to build new authentically functional groups: (i) going back to the seven initial ecological categories to provide greater accuracy than the usage of the simplified three-level classification; (ii) testing, for a set of selected species, the functionality of the groups, being ecological categories or new tailored ones; and (iii) using trait-based approach in order to study the correlation between some earthworm traits and main soil functions. [ABSTRACT FROM AUTHOR]

Although Humic-LIke Substances (HULIS) are important contributors to the mass of organic aerosol in airborne particulate matter (PM), little is known about their chemical composition, while, their size-resolved optical properties have not been studied yet. Here, HULIS fractions were isolated from size-resolved aerosol samples (≤0.49, 0.49–0.95, 0.95–3 and 3–10 μm) collected in urban and suburban environments of four European cities during wintertime. The bulk ( i.e. , sum of all size fractions) concentration of HULIS ranged between 1.29 and 2.80 μg m −3 across sites with highest values in the ≤0.49 μm particle size fraction. The contribution of the carbon mass of HULIS (HULIS-C) to the water-soluble organic carbon content (WSOC) of PM was 32–43%, which is typical for urban sites affected by biomass burning. The Mass Absorption Efficiency (MAE), which characterizes the efficiency of absorbing solar energy per carbon mass of HULIS decreased with particle size, suggesting that the finest size fractions contain more light-absorbing chromophores, which could affect the light-absorbing ability of organic aerosols. The good correlation of HULIS with effective biomass tracers such as K + , as well as with secondary inorganic aerosol components, proposed that HULIS had both primary ( i.e. , biomass burning) and secondary sources. The Fourier Transfer Infrared coupled to Attenuation Total Reflectance (FTIR-ATR) spectra demonstrated prevalence of aromatic over carboxylic functional groups in most HULIS fractions, indicating contribution from coal combustion emissions in addition to fresh biomass burning aerosol. The new findings add to better understanding the sources and chemical structure of HULIS in urban and suburban environments. [ABSTRACT FROM AUTHOR]

Soil biodiversity plays a key role in regulating the processes that underpin the delivery of ecosystem goods and services in terrestrial ecosystems. Agricultural intensification is known to change the diversity of individual groups of soil biota, but less is known about how intensification affects biodiversity of the soil food web as a whole, and whether or not these effects may be generalized across regions. We examined biodiversity in soil food webs from grasslands, extensive, and intensive rotations in four agricultural regions across Europe: in Sweden, the UK, the Czech Republic and Greece. Effects of land-use intensity were quantified based on structure and diversity among functional groups in the soil food web, as well as on community-weighted mean body mass of soil fauna. We also elucidate land-use intensity effects on diversity of taxonomic units within taxonomic groups of soil fauna. We found that between regions soil food web diversity measures were variable, but that increasing land-use intensity caused highly consistent responses. In particular, land-use intensification reduced the complexity in the soil food webs, as well as the community-weighted mean body mass of soil fauna. In all regions across Europe, species richness of earthworms, Collembolans, and oribatid mites was negatively affected by increased land-use intensity. The taxonomic distinctness, which is a measure of taxonomic relatedness of species in a community that is independent of species richness, was also reduced by land-use intensification. We conclude that intensive agriculture reduces soil biodiversity, making soil food webs less diverse and composed of smaller bodied organisms. Land-use intensification results in fewer functional groups of soil biota with fewer and taxonomically more closely related species. We discuss how these changes in soil biodiversity due to land-use intensification may threaten the functioning of soil in agricultural production systems. [ABSTRACT FROM AUTHOR]

Exotic plant invasions can alter ecosystem processes, particularly if the invasive species are functionally different from native species. We investigated whether such alterations can be explained by differences in functional traits between native and invasive plants of the same functional group or by differences in functional group affiliation. We compared six invasive forbs in Europe with six native forbs and six native graminoids in leaf and whole-plant traits, plasticity in response to nutrient supply and interspecific competition, litter decomposition rate, effects on soil nutrient availability, and allelopathy. All traits were measured in a series of pot experiments, and leaf traits additionally in the field. Invasive forbs differed from native forbs for only a few traits; they had less leaf chlorophyll and lower phosphorus (P) uptake from soil, but they tended to have a stronger allelopathic effect. The invasive forbs differed in many traits from the native graminoids, their leaves had lower tissue densities and a shorter life span, their litter decomposed faster and they had a lower nitrogen-use efficiency. Our results suggest that invasive forbs have the potential to alter ecosystem properties when invading graminoid-dominated and displacing native graminoids but not when displacing native forbs. [ABSTRACT FROM AUTHOR]

Aim Aspects of connectivity and continuity operating in the River Meuse were analysed for their contribution to the biodiversity of the floodplain. From this analysis of the diversity and composition of the meadow communities, we aimed to derive effective biodiversity conservation strategies. Location The River Meuse is one of the larger rivers in the European Western Plains ecoregion. The alluvial plains of the river have a long history of cultivation, and for these plains the floodplain meadow vegetation is a highly appreciated and valuable nature conservation asset. Method We sampled floodplain meadows from 400 km of the six geomorphic reaches of the middle to lower course of the River Meuse. For each, 50 vascular plant relevés were recorded, representing the spectrum of floodplain meadow communities of that reach. Beta diversity was calculated to quantify similarity in species pools between the reaches. A dissimilarity formula was used to determine the turnover between the reaches, and these dissimilarities were compared with a Mantel test to detect whether species composition of the floodplain meadows exhibited connectivity and continuity between the reaches. Species richness for the floodplain vegetation data of the reaches was compared with data for riparian invertebrate communities. The vegetation data sets were ordinated using detrended correspondence analysis (DCA) to reveal patterns in the floodplain meadow species composition, and the DCA axes were related to plant functional groups and population strategies. The axis scores of the species and plots were linked to river and plant species traits. Results We did not observe an overall continuity trend in similarity, nor one in diversity in a downstream direction. Lateral connectivity was highlighted by the dissimilarity between the reaches and in the influxes of species from adjacent ecoregions. The DCA ordination showed statistically significant separations between reaches and between the plant functional groups. The second DCA axis related to the longitudinal gradient of the river, whereas the first axis showed stronger correlations with river and plant species traits. We termed this axis the ‘disorder axis’. Plant invaders and avoiders are located at the left side of the disorder axis, whereas the true river-adapted categories of resisters and endurers are at the right extremity. Contributions to the disorder were identified in terms of connectivity with adjacent ecoregions and the physical disturbance regime of natural and anthropogenic perturbations, resulting in community changes between the reaches. Main conclusions We concluded that a single overall strategy for biodiversity conservation of the river or its floodplains is not feasible. Strategies can, however, be derived for separate river reaches based on functional groups in the communities, the disorder characteristics of the reach, and the influence of surrounding ecoregions. [ABSTRACT FROM AUTHOR]

Changing land use has a major impact on lichen diversity. This study attempts to identify patterns or trends of lichen functional groups along a land use gradient, ranging from natural forests to open agricultural landscape. In eight countries, covering six main European biogeographic regions, lichen vegetation was assessed according to a standardized scheme. Data on reproductive, vegetative and ecological traits was compiled and relative species richness for all classes of all traits calculated. Relationships between the land use gradient and relative species richness of trait classes were analysed. Open and intensively managed landscapes harbour more fertile species while sterile species are relatively more important in forests. This finding is also supported by analyses of different classes of dispersal propagules. The importance of species with the principal photobiont Trebouxia s.I. increases linearly with intensification of land use. A converse pattern is revealed by species with Trentepohlia. Concerning substratum specialization only generalists show an effect along the land use intensity gradient. Their relative species richness decreases from landscapes dominated by forests to open agricultural landscape. A considerable decline in the rare lichen species richness as a result of land intensification is predicted. [ABSTRACT FROM AUTHOR]

1. Restoration of ex-arable land to species-rich habitats has become common practice in Europe as a result of Agri-Environment Regulations. The results, however, are highly variable and often disappointing. Competition from weedy species as a result of high soil inorganic nitrogen levels can negatively affect the establishment and growth of desirable grassland plant species. One method that has been put forward to alter competitive interactions among plant species on restoration sites is the addition of carbon (C) to the soil. To make C addition a tool for successful restoration of species rich grassland, it should affect plant growth in a species-specific way. 2. We present results of a greenhouse study to assess the species-specific responses of 29 plant species to a range of C volumes added to the soil. Specifically, we tested whether functional group affiliation (legumes, other forbs and grasses), life form (annual and perennial) or nitrophilic status could explain parts of the variation in the response of the selected plant species to C addition. 3. Amending soil with increasing levels of C resulted in a log-linear reduction in biomass accumulation of all plant species tested, but the responses varied significantly between the plant species. Functional group and life form explained a significant amount of variation observed among the plant species tested. The response of legumes to C addition was less pronounced than that of other forbs and grasses. Grasses showed a decrease in shoot : root ratio in response to C addition, while the shoot : root ratio of legumes and forbs remained constant. A greater shoot biomass reduction in response to C addition was found for annual species than for perennial species. 4. No correlation was found between the slope of the regression of log biomass vs. the amount of C added and the Ellenberg N-values, indicating that there is no simple relationship between the nitrophilic status of a plant species and its response to C addition. 5. Synthesis and applications. The results suggest that adding C to soil is a promising tool in grassland restoration. C addition disproportionately reduced above-ground biomass accumulation by annual plant species and grasses, which often dominate early succession on ex-arable land. This may facilitate the establishment and growth of late-seral species and thus the restoration of species-rich grassland on ex-arable land. [ABSTRACT FROM AUTHOR]

The impact of changing environmental factors on Collembola communities was studied using a N–S transect formed by four European coniferous forests: A˚heden (northern Sweden), Skogaby (southern Sweden), Waldstein (Germany) and Aubure (France). The similarity between Collembola communities gradually decreased with increasing distance suggesting a significant impact of geographical factors on species composition. While the data show a northward decrease of collembolan abundance, no consistent trend in species richness, diversity, and evenness was detected. However, the dominance of Collembola life forms (eu-, hemi-, epedaphic) markedly changed along the transect, with euedaphic species dominating at the southernmost site and epedaphic species dominating at the northernmost site. In addition, the share of detritivorous species increased and that of fungivorous species decreased from south to north. It is concluded that latitudinal changes in environmental conditions have a strong impact on both abundance and functional structure of collembolan communities, but act within a framework set of geographical and historical impacts on the species composition. [Copyright &y& Elsevier]

The article presents the study on the effects of livestock grazing on the farmland bird communities in Europe. It states that the local extinction and recolonization of the ground-feeding insectivorous bird species were affected by the changes in grazing pressure, while species that feed on mixed diet were not affected by the changes. It suggests that the intensive grazing should be relaxed so larger areas of dry pastures can be grazed.

• Some earthworm species were assigned to two or more ecological categories by different researchers. • Marcel Bouché defined ecological categories using earthworm traits but without assignment rules. • Using PCA and random forest classification on Bouché's data, we redefined categories and the most influential traits. • Each species is now defined by three percentages of membership to the three main categories. In the early 70s, the soil biologist Marcel Bouché classified French earthworms species into defined ecological categories. This classification system was immensely successful and is still widely used to describe earthworm functional groups even outside of Europe. Bouché used morpho-anatomical traits to differentiate three main categories: epigeic, anecic and endogeic. However, the way species are assigned to a category was not explicitly described in Bouché's work. Thus, some earthworm species can still be assigned to two categories depending on the way researchers interpret Bouché's description. To solve these issues and avoid unnecessary controversies, we applied PCA and random forest models to the seminal data of Marcel Bouché (earthworm morpho-anatomical traits). Their assignment to Bouché's three main categories allowed us to statistically redefine the different categories and determine which traits are the most influential. We found that the three main traits were skin pigmentation (from none to black), body length (mean of the minimal and maximal values) and skin coloration (yes or no), followed by 10 other morphological and anatomical traits. We then used this approach to assign a likely category to all of the species studied by Bouché, resulting in a new triangular graph including other categories such as epi-anecic, endo-anecic, epi-endogeic and intermediate. Finally, we calculated the percentage that each species belongs to each main ecological category. This represents a paradigm shift and may change our vision of earthworm communities enabling the computation of the percentage of anecic, endogeic and epigeic species at the community level and thus overcoming the limits and debate about fixed ecological categories for each species. [ABSTRACT FROM AUTHOR]