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Higher temperatures can increase metabolic rates and carbon demands of invertebrate herbivores, which may shift leaf-chewing herbivory among plant functional groups differing in C:N (carbon:nitrogen) ratios. Biotic factors influencing herbivore species richness may modulate these temperature effects. Yet, systematic studies comparing leaf-chewing herbivory among plant functional groups in different habitats and landscapes along temperature gradients are lacking. This study was conducted on 80 plots covering large gradients of temperature, plant richness and land use in Bavaria, Germany. We investigated proportional leaf area loss by chewing invertebrates (‘herbivory’) in three plant functional groups on open herbaceous vegetation. As potential drivers, we considered local mean temperature (range 8.4–18.8 °C), multi-annual mean temperature (range 6.5–10.0 °C), local plant richness (species and family level, ranges 10–51 species, 5–25 families), adjacent habitat type (forest, grassland, arable field, settlement), proportion of grassland and landscape diversity (0.2–3 km scale). We observed differential responses of leaf-chewing herbivory among plant functional groups in response to plant richness (family level only) and habitat type, but not to grassland proportion, landscape diversity and temperature—except for multi-annual mean temperature influencing herbivory on grassland plots. Three-way interactions of plant functional group, temperature and predictors of plant richness or land use did not substantially impact herbivory. We conclude that abiotic and biotic factors can assert different effects on leaf-chewing herbivory among plant functional groups. At present, effects of plant richness and habitat type outweigh effects of temperature and landscape-scale land use on herbivory among legumes, forbs and grasses.

Bislang war es weitgehend unklar, welche Rolle die Humuspflege in der Bewirtschaftung der Bergwälder in den Bayerischen Alpen spielt. Eine Umfrage im Rahmen des Projektes «Alpenhumus als klimasensitiver C-Speicher und entscheidender Standortfaktor im Bergwald» sollte den aktuellen Wissensstand in der forstlichen Praxis klären und herausfinden, ob und welche unterstützenden Massnahmen notwendig sind, um die Humuspflege und den Humusaufbau in den Gebirgswäldern der Bayerischen Alpen zu verbessern. Die Rückmeldungen aus 29 Fragebögen zeigten, dass die Försterinnen und Förster den Anteil der Tangelhumusstandorte mit mehr als 15 cm Humusmächtigkeit in ihrem Zuständigkeitsgebiet auf knapp 20% schätzen. Hochgerechnet auf die Waldfläche der Bayerischen Alpen ergibt dies einen Anteil von rund 48 250 ha. Wichtigster Indikator des Forstpersonals für die Lokalisation mächtiger Humusauflagen ist die Bodenvegetation. Etwa 20% der Befragten geben einen sichtbaren Rückgang von Tangelhumus an. Als Hauptgefährdung für Tangelhumus nennen die Befragten die Bodenerosion, die Klimaerwärmung, das Ausbleiben der Verjüngung und die Kronennutzung. Als relevante Massnahmen zur Humuspflege geben sie das Belassen von Kronenmaterial im Bestand, die Einleitung und/oder Sicherstellung der Verjüngung sowie die Jagd an. Zur Verbesserung des Humusaufbaus wünschen sich die Befragten gezieltere Planungen, eine Änderung des Schalenwildmanagements und Schulungen für die Waldbesitzer. Verbesserte Karten mit Geodaten, eine Förderung der natürlichen Waldentwicklung und ein Leitfaden zur Humuspflege sollen dabei zusätzlich unterstützen.

1. Climate and land-use change are key drivers of environmental degradation in the Anthropocene, but too little is known about their interactive effects on biodiversity and ecosystem services. Long-term data on biodiversity trends are currently lacking. Furthermore, previous ecological studies have rarely considered climate and land use in a joint design, did not achieve variable independence or lost statistical power by not covering the full range of environmental gradients. 2. Here, we introduce a multi-scale space-for-time study design to disentangle effects of climate and land use on biodiversity and ecosystem services. The site selection approach coupled extensive GIS-based exploration (i.e. using a Geographic information system) and correlation heatmaps with a crossed and nested design covering regional, landscape and local scales. Its implementation in Bavaria (Germany) resulted in a set of study plots that maximise the potential range and independence of environmental variables at different spatial scales. 3. Stratifying the state of Bavaria into five climate zones (reference period 1981–2010) and three prevailing land-use types, that is, near-natural, agriculture and urban, resulted in 60 study regions (5.8 × 5.8 km quadrants) covering a mean annual temperature gradient of 5.6–9.8°C and a spatial extent of ~310 × 310 km. Within these regions, we nested 180 study plots located in contrasting local land-use types, that is, forests, grasslands, arable land or settlement (local climate gradient 4.5–10°C). This approach achieved low correlations between climate and land use (proportional cover) at the regional and landscape scale with |r ≤ 0.33| and |r ≤ 0.29| respectively. Furthermore, using correlation heatmaps for local plot selection reduced potentially confounding relationships between landscape composition and configuration for plots located in forests, arable land and settlements. 4. The suggested design expands upon previous research in covering a significant range of environmental gradients and including a diversity of dominant land-use types at different scales within different climatic contexts. It allows independent assessment of the relative contribution of multi-scale climate and land use on biodiversity and ecosystem services. Understanding potential interdependencies among global change drivers is essential to develop effective restoration and mitigation strategies against biodiversity decline, especially in expectation of future climatic changes. Importantly, this study also provides a baseline for long-term ecological monitoring programs.

Central European forests experience a substantial loss of open-forest organisms due to forest management and increasing nitrogen deposition. However, management strategies, removing different levels of nitrogen, have been rarely evaluated simultaneously. We tested the additive effects of coppicing and topsoil removal on communities of dung-inhabiting beetles compared to closed forests. We sampled 57 021 beetles, using baited pitfall traps exposed on 27 plots. Experimental treatments resulted in significantly different communities by promoting open-habitat species. While alpha diversity did not differ among treatments, gamma diversity of Geotrupidae and Scarabaeidae and beta diversity of Staphylinidae were higher in coppice than in forest. Functional diversity of rove beetles was higher in both, coppice and topsoil-removed plots, compared to control plots. This was likely driven by higher habitat heterogeneity in established forest openings. Five dung beetle species and four rove beetle species benefitted from coppicing, one red-listed dung beetle and two rove beetle species benefitted from topsoil removal. Our results demonstrate that dung-inhabiting beetles related to open forest patches can be promoted by both, coppicing and additional topsoil removal. A mosaic of coppice and bare-soil-rich patches can hence promote landscape-level gamma diversity of dung and rove beetles within forests.

The concept of potential natural vegetation (PNV) refers to self-sustaining mature vegetation matching the environmental conditions a site offers. Despite its widespread use, the applicability of t...

Oak-hornbeam forests (order Carpinetalia) are a widespread vegetation type in central Europe. As vegetation ecologists focused on them since the pioneering times of vegetation research, many syntaxonomic units are described. However, classification systems used in various central European countries suffer from inconsistencies and overlaps of the concepts of particular associations. Currently there is no consistent syntaxonomic system based on numerical analysis of vegetation plots that would be valid for the whole of central Europe. Therefore, the main goal of this study is to provide a revised syntaxonomic system of oak-hornbeam forests across central Europe, develop formal definitions of the associations and include these definitions in a classification expert system. We recognized 13 associations, 9 from the alliance Carpinion betuli (central European oak-hornbeam forests) and 4 from the alliance Erythronio-Carpinion (Illyrian and northern Italian oak-hornbeam forests). We prepared an expert system that classified 55% of the releves in a central European oak-hornbeam forest dataset (n = 6212) at the association level. To stabilize the Carpinion betuli association names, we selected nomenclatural type releves for associations that have not been typified so far. In addition, two association names (Poo chaixii-Carpinetum and Pseudostellario-Carpinetum) were validated. Ordination revealed the main drivers of species diversity in these forests, including a complex gradient of soil moisture, nutrient availability and geographical position (mainly latitude). Among the climate variables, annual temperature amplitude and mean annual temperature were most closely correlated with species composition.

Arthropod predators are important for ecosystem functioning by providing top-down regulation of insect herbivores. As predator communities and activity are influenced by biotic and abiotic factors on different spatial scales, the strength of top-down regulation (‘arthropod predation’) is also likely to vary. Understanding the combined effects of potential drivers on arthropod predation is urgently needed with regard to anthropogenic climate and land-use change. In a large-scale study, we recorded arthropod predation rates using artificial caterpillars on 113 plots of open herbaceous vegetation embedded in contrasting habitat types (forest, grassland, arable field, settlement) along climate and land-use gradients in Bavaria, Germany. As potential drivers we included habitat characteristics (habitat type, plant species richness, local mean temperature and mean relative humidity during artificial caterpillar exposure), landscape diversity (0.5–3.0-km, six scales), climate (multi-annual mean temperature, ‘MAT’) and interactive effects of habitat type with other drivers. We observed no substantial differences in arthropod predation rates between the studied habitat types, related to plant species richness and across the Bavarian-wide climatic gradient, but predation was limited when local mean temperatures were low and tended to decrease towards higher relative humidity. Arthropod predation rates increased towards more diverse landscapes at a 2-km scale. Interactive effects of habitat type with local weather conditions, plant species richness, landscape diversity and MAT were not observed. We conclude that landscape diversity favours high arthropod predation rates in open herbaceous vegetation independent of the dominant habitat in the vicinity. This finding may be harnessed to improve top-down control of herbivores, e.g. agricultural pests, but further research is needed for more specific recommendations on landscape management. The absence of MAT effects suggests that high predation rates may occur independent of moderate increases of MAT in the near future.

Changes in climate and land use are major threats to pollinating insects, an essential functional group. Here, we unravel the largely unknown interactive effects of both threats on seven pollinator taxa using a multiscale space-for-time approach across large climate and land-use gradients in a temperate region. Pollinator community composition, regional gamma diversity, and community dissimilarity (beta diversity) of pollinator taxa were shaped by climate-land-use interactions, while local alpha diversity was solely explained by their additive effects. Pollinator diversity increased with reduced land-use intensity (forest < grassland < arable land < urban) and high flowering-plant diversity at different spatial scales, and higher temperatures homogenized pollinator communities across regions. Our study reveals declines in pollinator diversity with land-use intensity at multiple spatial scales and regional community homogenization in warmer and drier climates. Management options at several scales are highlighted to mitigate impacts of climate change on pollinators and their ecosystem services.

QUESTIONS: Although thick forest floors overlying unweathered bedrock are important resources for mountain forests' functioning, their actual distribution is poorly known and difficult to delimit in the field. We therefore asked: (a) What is the specific composition of vegetation growing on Folic Histosols; (b) can indicator plants be used to detect Folic Histosols in mountain forests; (c) what do functional traits of plant indicators tell about the ecological properties of Folic Histosols? LOCATION: Northern Calcareous Alps, south Germany. METHODS: Based on representative stratified sampling of joint vegetation plots and soil profile descriptions, we estimated the frequency and thickness of Folic Histosols, determined the proportion of compositional variation specifically attributable to forest floor thickness using ordination, applied Indicator Species Analysis and searched for typical traits and ecological requirements of indicator species. RESULTS: The co‐existence of acidophilic and calciphytic plants is typical for the tessellated occurrence and the successional origin of Folic Histosols. In the study region, the detection of Folic Histosols on pure limestone or dolomite by ground vegetation works very well. Particularly acidophilic plants are suitable indicators for thick forest floors. The indicator value of bryophytes and Ericaceae for Folic Histosols is likely related to the colonization of rotten wood. Folic Histosol indicator species are widely spread in the allocation to sociology group, which ranges from open landscapes to dark forests and reflects successional origin. CONCLUSIONS: In mountain forests on carbonate bedrock, thick humus layers often occur next to bare rock. This tessellated structure can also be detected in the ground vegetation, where acidophilic and calciphytic plants occur side by side. Thick Folic Histosols in late successional forests are dominated by acidophilic plants colonizing rotten wood. Thus, the detection of Folic Histosols by understorey species is an easy and cost‐effective possibility and one key to protect these vulnerable forest sites.

Interactions between plants and herbivorous invertebrates drive the nutritional quality of resources for higher trophic levels, nutrient cycling and plant-community structure. Thereby, shifts in functional composition of plant communities particularly impact ecosystem processes. However, the current understanding of herbivory is limited concerning climate, land use and plant richness, as comparative studies of different plant functional groups are lacking. This study was conducted on 81 plots covering large climatic and land-use gradients in Bavaria, Germany. We investigated foliar invertebrate herbivory rates (proportional leaf-area loss, following ‘herbivory’) in three major plant functional groups (legumes, non-leguminous forbs, grasses). As drivers we considered multi-annual mean temperature (range: 6.5–10.0 °C), local habitat type (forest, grassland, arable field, settlement), local plant richness (species and family level, ranges: 10–50 species, 5–25 families) and landscape diversity (0.2–3-km scale). Our results largely confirm higher herbivory on legumes than on forbs and grasses. However, herbivory in forests was similar across plant functional groups since herbivory on legumes was low, e.g. lower than on legumes in grasslands. We also observed differential responses of herbivory among plant functional groups in response to plant richness (family level only), but not to landscape diversity. Temperature did not affect overall herbivory, but in grasslands higher temperature decreased herbivory on legumes and increased on forbs and grasses. We conclude that climate, habitat type and family-level plant richness likely assert different effects on herbivory among plant functional groups. This emphasises the importance of functional groups for understanding community-level herbivory and ecosystem functioning.

Datos disponibles en https://github.com/fmsabatini/sPlotOpen_Code, EU H2020 project BACI, Grant No. 640176 (...), Sabatini, F.M., Lenoir, J., Hattab, T., Arnst, E.A., Chytrý, M., Dengler, J., De Ruffray, P., Hennekens, S.M., Jandt, U., Jansen, F., Jiménez-Alfaro, B., Kattge, J., Levesley, A., Pillar, V.D., Purschke, O., Sandel, B., Sultana, F., Aavik, T., Aćić, S., Acosta, A.T.R., Agrillo, E., Alvarez, M., Apostolova, I., Arfin Khan, M.A.S., Arroyo, L., Attorre, F., Aubin, I., Banerjee, A., Bauters, M., Bergeron, Y., Bergmeier, E., Biurrun, I., Bjorkman, A.D., Bonari, G., Bondareva, V., Brunet, J., Čarni, A., Casella, L., Cayuela, L., Černý, T., Chepinoga, V., Csiky, J., Ćušterevska, R., De Bie, E., de Gasper, A.L., De Sanctis, M., Dimopoulos, P., Dolezal, J., Dziuba, T., El-Sheikh, M.A.E.-R.M., Enquist, B., Ewald, J., Fazayeli, F., Field, R., Finckh, M., Gachet, S., Galán-de-Mera, A., Garbolino, E., Gholizadeh, H., Giorgis, M., Golub, V., Alsos, I.G., Grytnes, J.-A., Guerin, G.R., Gutiérrez, A.G., Haider, S., Hatim, M.Z., Hérault, B., Hinojos Mendoza, G., Hölzel, N., Homeier, J., Hubau, W., Indreica, A., Janssen, J.A.M., Jedrzejek, B., Jentsch, A., Jürgens, N., Kącki, Z., Kapfer, J., Karger, D.N., Kavgacı, A., Kearsley, E., Kessler, M., Khanina, L., Killeen, T., Korolyuk, A., Kreft, H., Kühl, H.S., Kuzemko, A., Landucci, F., Lengyel, A., Lens, F., Lingner, D.V., Liu, H., Lysenko, T., Mahecha, M.D., Marcenò, C., Martynenko, V., Moeslund, J.E., Monteagudo Mendoza, A., Mucina, L., Müller, J.V., Munzinger, J., Naqinezhad, A., Noroozi, J., Nowak, A., Onyshchenko, V., Overbeck, G.E., Pärtel, M., Pauchard, A., Peet, R.K., Peñuelas, J., Pérez-Haase, A., Peterka, T., Petřík, P., Peyre, G., Phillips, O.L., Prokhorov, V., Rašomavičius, V., Revermann, R., Rivas-Torres, G., Rodwell, J.S., Ruprecht, E., Rūsiņa, S., Samimi, C., Schmidt, M., Schrodt, F., Shan, H., Shirokikh, P., Šibík, J., Šilc, U., Sklenář, P., Škvorc, Ž., Sparrow, B., Sperandii, M.G., Stančić, Z., Svenning, J.-C., Tang, Z., Tang, C.Q., Tsiripidis, I., Vanselow, K.A., Vásquez Martínez, R., Vassilev, K., Vélez-Martin, E., Venanzoni, R., Vibrans, A.C., Violle, C., Virtanen, R., von Wehrden, H., Wagner, V., Walker, D.A., Waller, D.M., Wang, H.-F., Wesche, K., Whitfeld, T.J.S., Willner, W., Wiser, S.K., Wohlgemuth, T., Yamalov, S., Zobel, M., Bruelheide, H.

Most plant communities consist of different structural and ecological subsets, ranging from cryptogams to different tree layers. The completeness and approach with which these subsets are sampled have implications for vegetation classification. Non‐vascular plants are often omitted or sometimes treated separately, referring to their assemblages as “synusiae” (e.g. epiphytes on bark, saxicolous species on rocks). The distinction of complete plant communities (phytocoenoses or holocoenoses) from their parts (synusiae or merocoenoses) is crucial to avoid logical problems and inconsistencies of the resulting classification systems. We here describe theoretical differences between the phytocoenosis as a whole and its parts, and outline consequences of this distinction for practise and terminology in vegetation classification. To implement a clearer separation, we call for modifications of the International Code of Phytosociological Nomenclature and the EuroVegChecklist. We believe that these steps will make vegetation classification systems better applicable and raise the recognition of the importance of non‐vascular plants in the vegetation as well as their interplay with vascular plants.

SummaryClimate and land-use change are key drivers of environmental degradation in the Anthropocene, but too little is known about their interactive effects on biodiversity and ecosystem services. Long-term data on biodiversity trends are currently lacking. Furthermore, previous ecological studies have rarely considered climate and land use in a joint design, did not achieve variable independence or lost statistical power by not covering the full range of environmental gradients.Here, we introduce a multi-scale space-for-time study design to disentangle effects of climate and land use on biodiversity and ecosystem services. The site selection approach coupled extensive GIS-based exploration and correlation heatmaps with a crossed and nested design covering regional, landscape and local scales. Its implementation in Bavaria (Germany) resulted in a set of study plots that maximizes the potential range and independence of environmental variables at different spatial scales.Stratifying the state of Bavaria into five climate zones and three prevailing land-use types, i.e. near-natural, agriculture and urban, resulted in 60 study regions covering a mean annual temperature gradient of 5.6–9.8 °C and a spatial extent of 380×360 km. Within these regions, we nested 180 study plots located in contrasting local land-use types, i.e. forests, grasslands, arable land or settlement (local climate gradient 4.5–10 °C). This approach achieved low correlations between climate and land-use (proportional cover) at the regional and landscape scale with |r ≤0.33| and |r ≤0.29|, respectively. Furthermore, using correlation heatmaps for local plot selection reduced potentially confounding relationships between landscape composition and configuration for plots located in forests, arable land and settlements.The suggested design expands upon previous research in covering a significant range of environmental gradients and including a diversity of dominant land-use types at different scales within different climatic contexts. It allows independent assessment of the relative contribution of multi-scale climate and land use on biodiversity and ecosystem services. Understanding potential interdependencies among global change drivers is essential to develop effective restoration and mitigation strategies against biodiversity decline, especially in expectation of future climatic changes. Importantly, this study also provides a baseline for long-term ecological monitoring programs.

Pouteau, R., et al., [Aim] The number of naturalized (i.e. established) alien species has increased rapidly over recent centuries. Given the differences in environmental tolerances among species, little is known about what factors determine the extent to which the observed size of the naturalized range of a species and hence the extent to which the observed richness of naturalized species of a region approach their full potential. Here, we asked which region- and species-specific characteristics explain differences between observed and expected naturalizations. [Location] Global. [Time period] Present. [Major taxa studied] Vascular plants. [Methods] We determined the observed naturalized distribution outside Europe for 1,485 species endemic to Europe using the Global Naturalized Alien Flora (GloNAF) database and their expected distributions outside Europe using species distribution models. First, we investigated which of seven socio-economic factors related to introduction pathways, anthropogenic pressures and inventory effort best explained the differences between observed and expected naturalized European floras. Second, we examined whether distributional features, economic use and functional traits explain the extent to which species have filled their expected ranges outside Europe. Results: In terms of suitable area, more than 95% of expected naturalizations of European plants were not yet observed. Species were naturalized in only 4.2% of their suitable regions outside of Europe (range filling) and in 0.4% of their unsuitable regions (range expansion). Anthropogenic habitat disturbance primarily explained the difference between observed and expected naturalized European floras, as did the number of treaties relevant to invasive species. Species of ornamental and economic value and with large specific leaf area performed better at filling and expanding beyond their expected range. Main conclusions: The naturalization of alien plant species is explained by climate matching but also by the regional level of human development, the introduction pressure associated with the ornamental and economic values of the species and their adaptation to disturbed environments., Robin Pouteau was supported by the National Natural Science Foundation of China (grant number 31901176) and Taizhou University (2018YQ001). Carsten Meyer acknowledges funding by the Volkswagen Foundation through a Freigeist Fellowship (A118199), and additional support by iDiv, funded by the German Research Foundation (DFG–FZT 118, 202548816). Petr Pyšek and Jan Pergl were supported by the Czech Science Foundation (EXPRO grant 19-28807X) and the Czech Academy of Sciences (long-term research development project RVO 67985939). Idoia Biurrun and Juan Antonio Campos were supported by the Basque Government (IT936-16). Gianmaria Bonari, Milan Chytrý, Ilona Knollová, Anna Kuzemko and Corrado Marcenò were supported by the Czech Science Foundation (19-28491X). Rosario G. Gavilán was supported by Madrid Government project REMEDINAL (P2018/EMT-4338). Jens-Christian Svenning considers this work a contribution to his VILLUM Investigator project ‘Biodiversity Dynamics in a Changing World’ funded by VILLUM FONDEN (16549). Mark van Kleunen was supported by the German Research Foundation DFG (264740629). The authors appreciate the helpful comments by three anonymous referees and the Handling Editor, Melodie A. McGeoch.

[Questions] European woodlands harbor at least 386 alien plant species but the factors driving local invasions remain unknown. By using a large vegetation-plot database, we asked how local richness and abundance of alien species vary by regions, elevation, climate, soil properties, human disturbance, and habitat types., [Location] Western, central and southern Europe., [Methods] We linked consolidated data from the European Vegetation Archive (16,211 plots) to a habitat classification scheme, climate, soil properties and human disturbance variables. In addition, we used 250 km × 250 km regional grid cells to test whether local patterns differ among regions. We used generalized additive models (GAMs) and quantile GAMs to explore how relative alien species richness and the sum of alien species covers per plot relate to predictors. Random Forest analyses (RFs) were employed to assess the importance of individual predictors that were not multicollinear., [Results] Relative alien species richness and the sum of alien species covers varied across regions and habitat types, with effects being more pronounced at the maximum rather than average responses. Both response variables declined with increasing elevation and distance to the nearest road or railroad and increased with the amount of sealed soil. Maxima in fitted functions matched plots from regional invasion hotspots in northwestern and central Europe. RFs accounted for 39.6% and 20.9% of the total variation in relative alien species richness and the sum of alien species covers, respectively, with region and habitat being the most important variables., [Conclusions] The importance of maximum response quantiles and the prevalence of regional hotspots point to invasion debt in European woodlands. As alien plants expand further, their species richness and abundance in woodlands will be likely driven by the shared effects of the introduction and planting history, differences in the invaded habitat types, and dispersal corridors., VW initiated this study as a part of the InvasEVe project financed by the SoMoPro II program and considers it as part of her Discovery Grant from the Canadian Natural Science and Engineering Research Council. VW's research leading to these results has acquired a financial grant from the People Program (Marie Curie Action) of the Seventh Framework Program of the EU according to REA Grant Agreement No. 291782, and it was further co-financed by the South-Moravian Region. MV and MC were supported by the Czech Science Foundation (19-28491X). PP and JP were supported by the Czech Science Foundation (19-28807X) and the Czech Academy of Sciences (RVO 67985939). JCS considers this work a contribution to his VILLUM Investigator project “Biodiversity Dynamics in a Changing World” funded by VILLUM FONDEN (grant 16549). IB and JAC were funded by the Basque Government (IT936-16). FFG was funded by the Plan Propio of the UCLM (2020-GRIN-29214)

Aim The EUNIS Habitat Classification is a widely used reference framework for European habitat types (habitats), but it lacks formal definitions of individual habitats that would enable their unequivocal identification. Our goal was to develop a tool for assigning vegetation-plot records to the habitats of the EUNIS system, use it to classify a European vegetation-plot database, and compile statistically-derived characteristic species combinations and distribution maps for these habitats. Location Europe. Methods We developed the classification expert system EUNIS-ESy, which contains definitions of individual EUNIS habitats based on their species composition and geographic location. Each habitat was formally defined as a formula in a computer language combining algebraic and set-theoretic concepts with formal logical operators. We applied this expert system to classify 1,261,373 vegetation plots from the European Vegetation Archive (EVA) and other databases. Then we determined diagnostic, constant and dominant species for each habitat by calculating species-to-habitat fidelity and constancy (occurrence frequency) in the classified data set. Finally, we mapped the plot locations for each habitat. Results Formal definitions were developed for 199 habitats at Level 3 of the EUNIS hierarchy, including 25 coastal, 18 wetland, 55 grassland, 43 shrubland, 46 forest and 12 man-made habitats. The expert system classified 1,125,121 vegetation plots to these habitat groups and 73,188 to other habitats, while 63,064 plots remained unclassified or were classified to more than one habitat. Data on each habitat were summarized in factsheets containing habitat description, distribution map, corresponding syntaxa and characteristic species combination. Conclusions EUNIS habitats were characterized for the first time in terms of their species composition and distribution, based on a classification of a European database of vegetation plots using the newly developed electronic expert system EUNIS-ESy. The data provided and the expert system have considerable potential for future use in European nature conservation planning, monitoring and assessment. The previous versions of the expert system and related reports were produced within a contract from the European Environment Agency to Wageningen Environmental Research and Masaryk University. The opinions expressed are those of the contractor and do not represent the Agency's official position. EVA data management and preparation of this paper were supported by the Czech Science Foundation (project no. 19-28491X to MC, LT, IK, TP, CM, JDa, MH, PN, DZ, GB, AJ, AKu, ZL and DV). IB and JAC were supported by the Basque Government (project no. T936-16). TB, ET, and LK were supported by the Ministry of Science and Higher Education of the Russian Federation (TB and ET project no. AAAA-A18-118052590019-7; LK project no. AAAA-A19-119012490096-2).

Grazed alpine pastures have shaped landscapes of the European Alps for millennia. However, especially steep alpine areas have largely been abandoned since the 1950s, resulting in a fast re-forestation of mountain pastures in the last decades, which is accelerated by climate change. Re-grazing of abandoned pastures could preserve the cultural landscape of the European Alps with its high species diversity, but there is a lack of information on the response of the soil system to re-grazing. We investigated short-term effects of re-grazing of an abandoned pasture in the German Alps on soil organic carbon and nitrogen biochemistry, soil microbial communities, and water quality. In May 2018, we set up a pilot grazing experiment at Brunnenkopfalm (1500-1700 m a.s.l.), abandoned since 1955. Four ha were fenced and a herd of rustic, local and endangered breeds (ca 1/ha) was introduced. Two and five months after the beginning of grazing, we investigated the short-term re-grazing effects, considering grazing-induced heterogeneity, as well as the distribution of vegetation types. In order to gain a functional understanding of soil responses to re-grazing, we used a wide array of techniques to characterize soil biogeochemical properties (salt-extractable and total organic carbon, gross nitrogen turnover rates, soil mineral nitrogen availability), as well as the abundance and characteristics of microbial communities (microbial biomass, phospholipid-derived fatty acids analysis, abundance of nitrogen-related microbial communities). A few months after re-grazing started, extractable organic carbon, gross nitrogen mineralisation rates and inorganic nitrogen concentrations were increased only in intensively grazing-affected areas with bare soil. Bare soils represented a small fraction of the study area (~ 1 %), and the grazing effects on these areas could at least partially also be driven by the initial site heterogeneity (soil and vegetation) rather than solely by recent grazing activities. Re-grazing did not affect the microbial abundance, but induced a community shift towards a smaller proportion of fungi compared to bacteria and an increase of ammonia oxidizers (archaea/bacteria). Concentrations of dissolved organic carbon and nitrate in the draining creek remained very low. Overall, re-grazing of pastures in the first season had very limited effects on microbial communities and associated carbon and nitrogen turnover and concentrations, highlighting the initial resilience of alpine soils to extensive re-grazing. However, a slight increase in nitrifier abundances at bare soil spots, as well as the low organic carbon:nitrogen ratios of soils suggest that a future increase in inorganic nitrogen accumulation is possible at least at bare soil areas. This could possibly endanger some biodiverse grassland biotopes via eutrophication and result in environmental nitrogen losses along hydrological or gaseous pathways. Thus, long-term studies are needed to verify whether soils are also resilient to re-grazing in the long-term. On the short-term, undesired re-grazing effects can be avoided by extensive, guided grazing with adapted cattle breeds targeted to avoid trampling-induced bare soil areas.

Grazed alpine pastures have shaped landscapes of the European Alps for millennia, but have partially been abandoned since the 1950s. Re-grazing of abandoned pastures could preserve this cultural landscape with its high species diversity, but also alter soil carbon and nitrogen cycles, as well as microbial communities, potentially affecting ecosystem services (e.g., water purification, carbon and nitrogen storage). However, there is a lack of information on the resistance of soil characteristics to re-grazing effects. After characterising the distribution of vegetation types of an abandoned pasture in the German Alps, we investigated short-term effects of re-grazing on soil organic carbon and nitrogen biochemistry, soil microbial communities, and water quality along a gradient of grazing intensity. The abandoned grassland studied presented a remarkably high diversity of species and habitats even 60 years after abandonment. It was also found to be particularly rich in terms of microbial biomass, as well as in soil carbon and nitrogen. A few months after re-grazing started, extractable organic carbon, gross nitrogen mineralisation rates and inorganic nitrogen concentrations were increased only in intensively grazing-affected areas with bare soil (i.e. concentration of cows with excreta inputs), which insignificantly contributed to the overall area. Re-grazing did not affect the microbial abundance, whatever the grazing intensity, but induced a community shift towards a smaller proportion of fungi compared to bacteria and an increase of ammonia oxidizers (archaea/bacteria) under bare soil conditions. Concentrations of dissolved organic carbon and nitrate in the draining creek remained very low. Overall, re-grazing of pastures in the first season had very limited effects on microbial communities and associated carbon and nitrogen turnover and concentrations, highlighting the resistance of the studied alpine soils to extensive re-grazing. Our results indicate how to develop sustainable management strategies that preserve alpine pastures from degradation.

The thickness and composition of forest floors plays an essential role for the efficiency and resilience of mountain forests to store carbon, water and nutrients. Up to now, the distribution of particularly thick organic forest floors (TOFF) in the Bavarian Calcareous Alps is poorly known and their ecosystem services deserve increased consideration under climate change. We wanted to improve the knowledge of the TOFF-distribution and to investigate the forcing processes and ecological functions of TOFF. We aimed to quantify their carbon storage potential and to model areas in which humus management is mandatory for sustainable forest use. We drew a stratified sample of soil profiles. Through the combination of relief and soil parameters, we identified crucial control variables and modelled actual and potential (without human disturbance) forest floor thickness in the Bavarian Calcareous Alps based on quantile regression and Generalized Additive Models (GAM). TOFF were predicted to occur on approximately 10% of the forest area of the Bavarian Alps. A decisive condition for the development of TOFF was the absence or only shallow development of mineral fine soil. Contrary to conventional wisdom, these TOFF were found across a wide range of (montane to subalpine) elevations. C-storage of TOFF amounts to ca. 6.9 t C/ha per cm of humus depth and ca. 5.2 Mt C in the study area, resulting in C accumulations comparable to peatlands. TOFF are decisive for the delivery of ecosystem services, especially in the protection forests of the Bavarian Calcareous Alps. Due to the absence or ephemeral depth of mineral soil, all ecological functions depend solely on the forest floor. Therefore, the careful handling of the humus stock is mandatory for a sustainable management in these forests.

Phenological responses to changing temperatures are known as “fingerprints of climate change,” yet these reactions are highly species specific. To assess whether different plant characteristics are related to these species‐specific responses in flowering phenology, we observed the first flowering day (FFD) of ten herbaceous species along two elevational gradients, representing temperature gradients. On the same populations, we measured traits being associated with (1) plant performance (specific leaf area), (2) leaf biochemistry (leaf C, N, P, K, and Mg content), and (3) water‐use efficiency (stomatal pore area index and stable carbon isotopes concentration). We found that as elevation increased, FFD was delayed for all species with a highly species‐specific rate. Populations at higher elevations needed less temperature accumulation to start flowering than populations of the same species at lower elevations. Surprisingly, traits explained a higher proportion of variance in the phenological data than elevation. Earlier flowering was associated with higher water‐use efficiency, higher leaf C, and lower leaf P content. In addition to that, the intensity of shifts in FFD was related to leaf N and K. These results propose that traits have a high potential in explaining phenological variations, which even surpassed the effect of temperature changes in our study. Therefore, they have a high potential to be included in future analyses studying the effects of climate change and will help to improve predictions of vegetation changes.

Aim The former continental‐scale studies modelled coarse‐grained plant species‐richness patterns (gamma diversity). Here we aim to refine this information for European forests by (a) modelling the number of vascular plant species that co‐occur in local communities (alpha diversity) within spatial units of 400 m2; and (b) assessing the factors likely determining the observed spatial patterns in alpha diversity. Location Europe roughly within 12°W–30°E and 35–60°N. Taxon Vascular plants. Methods The numbers of co‐occurring vascular plant species were counted in 73,134 georeferenced vegetation plots. Each plot was classified by an expert system into deciduous broadleaf, coniferous or sclerophyllous forest. Random Forest models were used to map and explain spatial patterns in alpha diversity for each forest type separately using 19 environmental, land‐use and historical variables. Results Our models explained from 51.0% to 70.9% of the variation in forest alpha diversity. The modelled alpha‐diversity pattern was dominated by a marked gradient from species‐poor north‐western to species‐rich south‐eastern Europe. The most prominent richness hotspots were identified in the Calcareous Alps and adjacent north‐western Dinarides, the Carpathian foothills in Romania and the Western Carpathians in Slovakia. Energy‐related factors, bedrock types and terrain ruggedness were identified as the main variables underlying the observed richness patterns. Alpha diversity increases especially with temperature seasonality in deciduous broadleaf forests, on limestone bedrock in coniferous forests and in areas with low annual actual evapotranspiration in sclerophyllous forests. Main conclusions We provide the first predictive maps and analyses of environmental factors driving the alpha diversity of vascular plants across European forests. Such information is important for the general understanding of European biodiversity. This study also demonstrates a high potential of vegetation‐plot databases as sources for robust estimation of the number of vascular plant species that co‐occur at fine spatial grains across large areas., M.V., J.D., I.K., M.Ř. and M.C. were supported by the Czech Science Foundation (Centre of Excellence Pladias; project no. 14–36079G). I.B. and J.A.C. were supported by the Basque Government (IT936‐16). B.J.‐A. was supported by the Marie Curie Clarín‐COFUND program of the Principate of Asturias and the European Union (ACB17‐26). J.‐C.S. considers this work a contribution to his VILLUM Investigator project “Biodiversity Dynamics in a Changing World” funded by VILLUM FONDEN (grant 16549) and his Danish Council for Independent Research | Natural Sciences TREECHANGE project (grant 6108‐00078B).

Questions Ellenberg nutrient values based on indicator plant species composition of vegetation plots (mN) are widely used to measure temporal and spatial patterns of nutrient deficiency and eutrophication. The widespread use is in contrast to the lack of direct calibration against soil chemical proxies of nutrient availability. Lack of calibration and range contraction due to averaging of a bounded ordinal scale hinder the interpretation of mN across studies. Based on a large set of concomitant vegetation–soil data we asked: (1) which is the best single soil predictor of mN, (2) which combination of soil variables best explains mN; and (3) can a meaningful relative scale of mN be provided for comparative purposes? Location Forests in Germany, sampled in a systematic 8 km × 8 km grid. Methods The German National Forest Soil Inventory (NFSI) provides a large, representative sample of joint soil and vegetation plots, which were additionally intersected with modelled background N deposition. Values of mN of vegetation plots were related to measured 36 soil and three deposition variables by correlation and multiple regression. The distribution of mN was partitioned based on quantiles. Results In NFSI mN was most closely related to the C/N ratio of the topsoil (r² = 0.31). Multiple analysis regression showed that soil acidity, soil P and K, humus quality and deposition were complementary predictors (multiple r² = 0.47) of mN. Conclusions Values of mN are moderately, but consistently, related to measurable chemical properties of forest soils. The 10, 30, 70 and 90% quantiles of the frequency distribution of mN in the NFSI data are proposed to define a relative scale of macronutrient availability in forest soils, distinguishing very oligotrophic (mN 6.21) sites, which broadly correspond to conventional classes of C/N ratio used in forest site mapping. This proposed five-class trophic scale can be used to compare mN and its trends across studies in forest vegetation of Central Europe.

In the face of climate warming, maps of potential tree species distribution can support forest management planning at coarse scales. For evaluating future suitability, conditions at the rear edge, i.e. at the meridional and lower altitudinal limits of species distribution, are of particular importance. Therefore, we present the concept of climatic marginality (distance to the rear edge) as a metric for the susceptibility against climate warming. Using a statistic niche model fitted to observed and potential beech occurrence in ICP Forests Level I monitoring plots and WorldClim data, we evaluate the modelled xeric limit of European beech based on the Ellenberg’s climate quotient involving thresholds suggested by Ellenberg and other authors. The applicability of the marginality index was tested with independent study sites. Despite the limitations of niche modelling, estimated climatic thresholds of beech were well in accordance with textbook knowledge and recent research. The regional patterns of climatic marginality were plausible and more meaningful with respect to the rear edge compared to conventional niche model outputs. In terms of climatic marginality, most regions in Central Europe are far from the xeric limit of beech. Evaluation based on independently sampled sites indicated that inclusion of soil and topography (microclimate) may permit implications at the local scale, e.g. growth potential estimations.

Because of some land-use practices (such as overstocking with wild ungulates, historical clear-cuts for mining, and locally persisting forest pasture), protective forests in the montane vegetation belt of the Northern Limestone Alps are now frequently overaged and poorly structured over large areas. Windthrow and bark beetle infestations have generated disturbance areas in which forests have lost their protective functions. Where unfavorable site conditions hamper regeneration for decades, severe soil loss may ensue. To help prioritize management interventions, we developed a geographic information system-based model for assessing sensitivity to site degradation and applied it to 4 test areas in the Northern Limestone Alps of Austria and Bavaria. The model consists of (1) analysis of site conditions and forest stand structures that could increase sensitivity to degradation, (2) evaluation of the sensitivity of sites and stands, and (3) evaluation and mapping of mountain forests' sensitivity to degradation. Site conditions were modeled using regression algorithms with data on site parameters from pointwise soil and vegetation surveys as responses and areawide geodata on climate, relief, and substrate as predictors. The resulting predictor–response relationships were applied to test areas. Stand structure was detected from airborne laser scanning data. Site and stand parameters were evaluated according to their sensitivity to site degradation. Sensitivities of sites and stands were summarized in intermediate-scale sensitivity maps. High sensitivity was identified in 3 test areas with pure limestone and dolomite as the prevailing sensitivity level. Moderately sensitive forests dominate in the final test area, Grünstein, where the bedrock in some strata contains larger amounts of siliceous components (marl, mudstone, and moraines); degraded and slightly sensitive forests were rare or nonexistent in all 4 test areas. Providing a comprehensive overview of site and forest stand structure sensitivity to site degradation, our sensitivity maps can serve as a planning instrument for the management and protection of mountain forests.

QuestionsWhat are the main floristic patterns in European beech forests? Which classification at the alliance and suballiance level is the most convincing?LocationEurope and Asia Minor.MethodsWe applied a TWINSPAN classification to a data set of 24605 releves covering the whole range of Fagus sylvatica forests and the western part of Fagus orientalis forests. We identified 24 operational phytosociological units' (OPUs), which were used for further analysis. The position of each OPU along the soil pH and temperature gradient was evaluated using Ellenberg Indicator Values. Fidelity of species to OPUs was calculated using the phi coefficient and constancy ratio. We compared alternative alliance concepts, corresponding to groups of OPUs, in terms of number and frequency of diagnostic species. We also established formal definitions for the various alliance concepts based on comparison of the total cover of the diagnostic species groups, and evaluated alternative geographical subdivisions of beech forests.ResultsThe first and second division levels of TWINSPAN followed the temperature and soil pH gradients, while lower divisions were mainly geographical. We grouped the 22 OPUs of Fagus sylvatica forests into acidophytic, meso-basiphytic and thermo-basiphytic beech forests, and separated two OPUs of F.orientalis forests. However, a solution with only two ecologically defined alliances of F.sylvatica forests (acidophytic vs basiphytic) was clearly superior with regard to number and frequency of diagnostic species. In contrast, when comparing groupings with three to six geographical alliances of basiphytic beech forests, respectively, we did not find a strongly superior solution.ConclusionsWe propose to classify F.sylvatica forests into 15 suballiances - three acidophytic and 12 basiphytic ones. Separating these two groups at alliance or order level was clearly supported by our results. Concerning the grouping of the 12 basiphytic suballiances into ecological or geographical alliances, as advocated by many authors, we failed to find an optimal solution. Therefore, we propose a multi-dimensional classification of basiphytic beech forests, including both ecological and geographical groups as equally valid concepts which may be used alternatively depending on the purpose and context of the classification.

Aim: Woodlands make up a third of European territory and carry out important ecosystem functions, yet a comprehensive overview of their invasion by alien plants has never been undertaken across this continent. Location: Europe. Methods: We extracted data from 251,740 vegetation plots stored in the recently compiled European Vegetation Archive. After filtering (resulting in 83,396 plots; 39 regions; 1970–2015 time period), we analysed the species pool and frequency of alien vascular plants with respect to geographic origin and life-forms, and the levels of invasion across the European Nature Information System (EUNIS) woodland habitats. Results: We found a total of 386 alien plant species (comprising 7% of all recorded vascular plants). Aliens originating from outside of and from within Europe were almost equally represented in the species pool (192 vs. 181 species) but relative frequency was skewed towards the former group (77% vs. 22%) due, to some extent, to the frequent occurrence of Impatiens parviflora (21% frequency among alien plants). Phanerophytes were the most species-rich life-form (148 species) and had the highest representation in terms of relative frequency (39%) among aliens in the dataset. Apart from Europe (181 species), North America was the most important source of alien plants (109 species). At the local scale, temperate and boreal softwood riparian woodland (5%) and mire and mountain coniferous woodland (

A combined systematic and stratified sampling design was conducted in mountain forests of the Bavarian Alps to find the principal dimensions of compositional variation of vegetation and their environmental drivers. In 1,505 plots species composition, forest types and soil profiles were recorded. Data from 14 climate stations were included. As we hypothesized that the tree layer is more influenced by management than the understorey and that the former modifies the habitat of the latter, the two matrices were analysed separately and the species composition of the tree layer was used as a structural predictor variable for the understorey. We applied constrained ordination to reveal the main gradients in floristic composition and variance partitioning to examine the portions of climatic, edaphic, spatial and structural components. Ellenberg indicator values and a generalized linear model were used to test whether a significant spatial gradient exists from east to west, the main spatial extent of the investigation area. Forest types were used as an overlay to assess the underlying environmental factors. It turned out that explained variance of the tree layer was considerably lower than in the understorey. Tree layer composition was more influenced by climatic variables than by soil. In the understorey, edaphic and climatic variables contributed almost equally to explained variance, but the tree layer had an additional explanatory power. No continentality gradient could be detected within the investigation area. Plant communities were well separated along gradients of acidity, moisture, nutrients and climate, which broadly confirms the known gradients for montane and subalpine zonal forests in the region. The study provides a quantitative synthesis of the knowledge on a diverse set of community types, which has so far been subject to disparate and sectorial treatment in the Bavarian Alps.

In the face of global change, the mapping of vegetation and its underlying site conditions has re-entered the focus of applied vegetation science. Thus, land managers, conservationists and scientists require a new generation of mapped and interpreted environmental information as a basis for scenario building, planning and decision making. Nowadays, such mapping is rarely performed by experts in the field, but rather by the synthesis of ecological information from point data and area-wide layers stored in geographical information systems (GIS). The prerequisites and main reasons to prefer these methods are (1) the availability of point data from vegetation plots and concomitant soil profiles, (2) availability of high resolution geo-physical data, and (3) the predictive potential of models that allow the application of climate change scenarios.

The hypothesis that soil chemistry is a main constraint for the vigour of Norway spruce trees on calcareous soils is scrutinised based on data from 60 existing and new intensive study sites in the Bavarian Alps, where comprehensive information on soils, climate, foliar nutrient concentration, ground vegetation, and tree growth is available. We characterised ecological gradients of the response variables site index (SI), foliar nutrient level and needle weight by constrained ordination, identified nutrient limitations based on regression trees and modelled SI based on vegetation-based mean Ellenberg indicator values. Our study confirms the assumption that soil development and concurrent acidification are key determinants for the vitality and growth of spruce in the Bavarian Alps, which surpass the importance of climate on nutrition and growth. Pools and availability of P and N are limiting nutrition and growth of spruce in this region. We hypothesize that N-limitation persists despite considerable deposition inputs because N tends to be locked up in organic horizons with low biological activity. K and trace elements, especially Fe, can also be deficient in some cases but do not appear as major limiting factors. High foliar Mn concentrations are a reliable indicator of mature soils and favourable site conditions in the Bavarian Alps, but Mn itself is usually not limiting. P must be regarded as the most critical macronutrient in the Bavarian Alps, particularly in the face of biomass harvesting. Consequently, at sites with shallow soils forest, management should focus on sustaining or restoring humus stocks. SI of spruce can be predicted from composition of ground vegetation and Ellenberg indicator values with remarkable precision (R 2 = 0.75).

Are there differences in historical and recent upper range limits of vascular plants and are such differences more pronounced in individual species groups? The limits of 1103 plants of the Northern Alps are compared to range limits in the mid-19th century. The comparison is based on two surveys. The first survey was conducted by Otto Sendtner in 1848–1853, the second in 1991–2008 during a habitat inventory. To our knowledge this is the first comparative studies reaching back to the end of the “Little Ice Age” and comprising an almost entire regional flora covering the complete range of habitats. During the recent survey, most species were found at higher elevations. Even though the differences fit well with the expected shifts due to climate warming we cannot exclude effects of sampling bias. However, we assume that the relative differences between species groups can be safely interpreted. The differences in upper limits between both surveys were significantly larger among forest species. The most important reason is probably discontinued pasture and mowing, which may have amplified possible warming effects. Nitrogen deposits may have contributed to this effect by placing competitive species in a more advantageous position.

Forest soils represent an important part of the global C cycle as they store large amounts of organic carbon (OC). With its great importance for nutrient and water supply, soil organic matter (SOM) is a key site characteristic particularly in shallow mountain soils. We conducted soil humus inventories in three research areas in the Bavarian Limestone Alps to investigate long-term effects of historical forest management with selective harvesting on shallow calcareous mountain forest soils. In each research area, SOM stocks under unmanaged forest at remote sites representing the virgin forest status and those of nearby selectively harvested forest stands (repeated single tree extraction, shelterwood harvesting) with identical site factors were compared in a paired-plot approach. At each site, five soil profiles were investigated; additionally O layer thickness was measured as well as important stand characteristics were assessed at 30 points of an orthogonal grid net that had been established in each stand. OC and N stocks in the forest floor and in the mineral soil were calculated by horizon as well as by depth increment and evaluated statistically. On average, forest floor OC and N stocks were reduced by about 80% under managed forest (OC stock 25 ± 34 Mg ha−1; N stock 1.0 ± 1.5 Mg ha−1) compared to nearby unmanaged forest (OC stock 114 ± 123 Mg ha−1; N stock 4.5 ± 5.1 Mg ha−1). OC and N stocks in the mineral topsoil (0–30 cm) were larger under managed (OC stock 65 ± 22 Mg ha−1; N stock 4.4 ± 1.4 Mg ha−1) compared to unmanaged stands (OC stock 55 ± 38 Mg ha−1; N stock 3.6 ± 2.8 Mg ha−1). Total topsoil (forest floor + mineral topsoil) OC and N stocks under managed forest (OC stock 89 ± 36 Mg ha−1; N stock 5.4 ± 1.6 Mg ha−1) exhibited significant OC losses of 47% and N losses of 33% compared to nearby unmanaged forest (OC stock 169 ± 96 Mg ha−1; N stock 8.1 ± 3.4 Mg ha−1). Hence we conclude that standard forest management as practiced since ca. 200 years has considerably reduced SOM stocks on shallow calcareous mountain forest soils in the Bavarian Limestone Alps.

Height growth and productivity of forests depend on temperature, water and nutrients. Ellenberg indicator values that summarize vegetation response to growth factors are suited to predict site fertility. Macronutrients (NPK), as represented by N-values, are a crucial component of site fertility and susceptibility towards biomass extraction. Based on 1,500 vegetation plots from an inventory stratified over all important forest types of the Bavarian Alps we regionalized Ellenberg N-values against area-wide soil, climate and relief predictors including a spatial effect at a scale of 1 : 25,000, resulting in a general additive model (GAM) with eight predictors and an explained deviance of 53 % on test data. The N-value layer was combined with other regionalized indicator values (temperature, reaction, moisture) to predict height of Norway spruce at reference age (site index) of an independent forest inventory data set, resulting in a GAM with an explained deviance of 35 %. After temperature the nutrient value was the second most important predictor of site index and clearly superior to soil reaction. It can be concluded that forest growth is sensitive to reductions of NPK-availability through whole tree harvesting and that maps of N-values deliver important information for planning sustainable harvesting.

We present an approach to produce maps of Ellenberg values for soil reaction (R-value) in the Bavarian Alps. Eleven meaningful environmental predictors covering GIS-derived information on climatic, topographic and soil conditions were used to predict R-values. As dependent variables, Ellenberg indicator values for soil reaction were queried from plot records in the vegetation database WINALPecobase. We used an additive georegression model, which combines complex prediction models and the increased prediction accuracy of a boosting algorithm. In addition to environmental predictors we included spatial effects into the model to account for spatial autocorrelation. As we were particularly interested in the usefulness of averaged R-values for spatial prediction, we applied two different models: (1) a geo-additive regression model that estimates mean R-values and (2) a proportional odds model predicting the probability distribution over R-values 1 to 9. We found meaningful dependencies between the R-value and our predictors. Both models produced the same spatial pattern of predictions. Spatial effects had an impact only in the first model. The main drawback of mean R-values is the oversimplification of complex conditions of soil reaction, which is entailed by averaging and regression to mean values. Therefore, regionalized average indicator values provide only limited information on site-ecological characteristics. Model 1 failed to predict the range and shapes of original indicator spectra precisely. In contrast, the second model provided a more sophisticated picture of soil reaction. To make the multivariate output of model 2 comparable to that of model 1, we propose to plot the distribution in a three-dimensional color-space. In addition, comparison of both models based on a multiple linear regression model resulted in a R 2 of 0.93. The proportional odds model is a promising approach also for other indicator values and different regions as well as for other ordinal-scaled ecological parameters.

Due to advances in spatial modeling and improved availability of digital geodata, traditional mapping of potential natural vegetation (PNV) can be replaced by ecological modeling approaches. We developed a new model to map forest types representing the potential natural forest vegetation in the Bavarian Alps. The TRM model is founded on a three-dimensional system of the ecological gradients temperature (T), soil reaction (R), and soil moisture (M). Within such a “site cube” forest types are defined as homogenous site units that give rise to forest communities with comparable species composition, structure, production and protective functions. The three gradients were modeled using regression algorithms with area-wide, high resolution geodata on climate, relief and soil as predictors and average Ellenberg indicator values for temperature, acidity and moisture of vegetation plots as dependent variables summarizing plant responses to ecological gradients. The resulting predictor-response relationships allowed us to predict gradient positions of each raster cell in the region from geodata layers. The three-dimensional system of gradients was partitioned into 26 forest types, which can be mapped for the whole region. TRM-based units are supplemented by 22 forest types of special sites defined by other ecological factors such as geomorphology, for which individual GIS rules were developed. The application of our model results in an intermediate-scale map of potential natural forest vegetation, which is based on an explicit function of temperature, reaction and moisture and is therefore consistent and repeatable in contrast to traditional PNV maps.

Aim To examining whether niche breadth, niche position and a compound measure of the two variables help to explain the range sizes of forest vascular plants. Locations Deciduous forests in two regions of Germany, the Weser–Elbe region and Bavarian Alps. Methods We compiled range size data for vascular plant species (30 in the Weser–Elbe region, 35 in the Bavarian Alps) on regional, national and continental scales by determining the area of occupancy (number of occupied grid cells) in both regions, Germany and Eurasia. Estimates of realized niche breadth and niche position (ecological optimum) for soil pH and light were based on measurements in 46 sites for all species. Frequency distributions of pH values on regional and national scales served to calculate the ‘available niche breadth’, i.e. niche breadth values corrected for the different availabilities of pH values in the region and country. Results Regional range size in the Weser–Elbe region increased with increasing niche breadth for both soil pH and light and with decreasing pH niche position. pH niche breadth was positively correlated to national range size in the Weser–Elbe region and to Eurasian range size in the Bavarian Alps. In the latter region, all other relationships with range size were (partly marginally) non-significant. Available niche breadth was generally more closely related to the regional and national distribution of species in both regions than either niche breadth or position alone. Main conclusions Niche breadth and position performed well as predictors of range size only for soil pH and in the Weser–Elbe region, which shows more homogeneous environmental conditions than the Bavarian Alps. If the frequencies of different ranges of pH values can be quantified, the calculation of available niche breadth for soil pH appears to be a promising approach for assessing the possible effects of niche variables on the range sizes of species.

Biurrun, Idoia/0000-0002-1454-0433; Rojo, Maria Pilar Rodriguez/0000-0001-5449-9386; Ermakov, Nikolai/0000-0001-7550-990X; De Sanctis, Michele/0000-0002-7280-6199; Svenning, Jens-Christian/0000-0002-3415-0862; Virtanen, Risto/0000-0002-8295-8217; Agrillo, Emiliano/0000-0003-2346-8346; Onyshchenko, Viktor/0000-0001-9079-7241; Marceno, Corrado/0000-0003-4361-5200; Willner, Wolfgang/0000-0003-1591-8386; Fernandez-Gonzalez, Federico/0000-0003-1234-4065; Jansen, Florian/0000-0002-0331-5185; Swacha, Grzegorz/0000-0002-6380-2954; Dengler, Jurgen/0000-0003-3221-660X; Guarino, Riccardo/0000-0003-0106-9416; Sopotlieva, Desislava/0000-0002-9281-7039; Venanzoni, Roberto/0000-0002-7768-0468; Chytry, Milan/0000-0002-8122-3075; Kuzemko, Anna/0000-0002-9425-2756; Danihelka, Jiri/0000-0002-2640-7867; Kuzemko, Anna/0000-0002-9425-2756; Venanzoni, Roberto/0000-0002-7768-0468; Gavilan, Rosario G./0000-0002-1022-445X; Jansen, Florian/0000-0002-0331-5185; Wohlgemuth, Thomas/0000-0002-4623-0894; Svenning, Jens-Christian/0000-0002-3415-0862; Sibik, Jozef/0000-0002-5949-862X; Casella, Laura/0000-0003-2550-3010; Lenoir, Jonathan/0000-0003-0638-9582; Attorre, Fabio/0000-0002-7744-2195; Kacki, Zygmunt/0000-0002-2241-1631; Jandt, Ute/0000-0002-3177-3669; Carni, Andraz/0000-0002-8909-4298; Jirousek, Martin/0000-0002-4293-478X; GARCIA-MIJANGOS, ITZIAR/0000-0002-6642-7782; Campos, Juan Antonio/0000-0001-5992-2753; Fanelli, Giuliano/0000-0002-3143-1212; Haveman, Rense/0000-0001-9127-4549; Acic, Svetlana/0000-0001-6553-3797; De Bie, Els/0000-0001-7679-743X; Font, Xavier/0000-0002-7253-8905; Moeslund, Jesper Erenskjold/0000-0001-8591-7149; Martynenko, Vasiliy/0000-0002-9071-3789; Jimenez-Alfaro, Borja/0000-0001-6601-9597; Ejrnaes, Rasmus/0000-0003-2538-8606; Carlon Ruiz, Luis/0000-0003-3442-8710; Angelini, Pierangela/0000-0002-5321-9757; Silc, Urban/0000-0002-3052-699X; Landucci, Flavia/0000-0002-6848-0384; Ewald, Jorg/0000-0002-2758-9324; Dziuba, Tetiana/0000-0001-8621-0890 WOS: 000368074600018 The European Vegetation Archive (EVA) is a centralized database of European vegetation plots developed by the IAVS Working Group European Vegetation Survey. It has been in development since 2012 and first made available for use in research projects in 2014. It stores copies of national and regional vegetation-plot databases on a single software platform. Data storage in EVA does not affect on-going independent development of the contributing databases, which remain the property of the data contributors. EVA uses a prototype of the database management software TURBOVEG 3 developed for joint management of multiple databases that use different species lists. This is facilitated by the SynBioSys Taxon Database, a system of taxon names and concepts used in the individual European databases and their corresponding names on a unified list of European flora. TURBOVEG 3 also includes procedures for handling data requests, selections and provisions according to the approved EVA Data Property and Governance Rules. By 30 June 2015, 61 databases from all European regions have joined EVA, contributing in total 1 027 376 vegetation plots, 82% of them with geographic coordinates, from 57 countries. EVA provides a unique data source for large-scale analyses of European vegetation diversity both for fundamental research and nature conservation applications. Updated information on EVA is available online at http://euroveg.org/eva-database. Czech Science Foundation (Centre of Excellence PLADIAS) [14-36079G] Our major thanks go to thousands of European vegetation scientists of several generations who collected the original vegetation-plot data in the field, published them or made their unpublished data available to others, and to those who spent myriad hours digitizing data and managing the contributing databases. EVA data management has been partly funded by the Czech Science Foundation (Centre of Excellence PLADIAS, 14-36079G).

Biomass equations are a helpful tool to estimate the tree and stand biomass production and standing stock. Such estimations are of great interest for science but also of great importance for global reports on the carbon cycle and the global climate system. Even though there are various collections and generic meta-analyses available with biomass equations for mature trees, reports on biomass equations for juvenile trees (seedlings and saplings) are mainly missing. Against the background of an increasing amount of reforestation and afforestation projects and forests in young successional stages, such equations are required. In this study we have collected data from various studies on the aboveground woody biomass of 19 common tree species growing in Europe. The aim of this paper was to calculate species-specific biomass equations for the aboveground woody biomass of single trees in dependence of root-collar-diameter (RCD), height (H) and the combination of the two (RCD2 H). Next to calculating species-specific biomass equations for the species available in the dataset, we also calculated generic biomass equations for all broadleaved species and all conifer species. The biomass equations should be a contribution to the pool of published biomass equations, whereas the novelty is here that the equations were exclusively derived for young trees. We thank the national research project “Ecosystem Services of Natural Forests at Forestry and Climate Policy (FKZ 3511 84 0200),” from the Federal Agency for Nature Conservation (BfN) of the Federal Ministry for the Environment Nature Conservation and Nuclear Safety (BMU) for funding this project.

Thermal limits of tree species are of paramount interest in monitoring and projecting effects of climate warming. Based on the large phytosociological database BERGWALD, a database of forest inventory plots, and phytosociological tables of vegetation above treeline, tree species occurrence along a regional elevation gradient was assessed separately for tree and regeneration layer individuals. Upper limits in the database were compared to altitudinal limits given in Oberdorfer’s regional flora and to northern latitudinal limits given in worldwide distribution maps. For 26 of 32 tree species, the known distribution limits had to be raised based on plot data, demonstrating the high potential of vegetation databases to deliver ecological information. In most species, regeneration layer occurrences markedly exceeded the altitudinal limit of trees, indicating a potential for rather rapid advances of treelines under climate warming. Regional altitudinal and global latitudinal limits were quite closely related in the majority of tree species. However, several tree species climb to much higher elevation in the Alps than their latitudinal limits suggest. The boreal-subalpine mismatch in cold limits is only partly explained by vicariism and endemism. Sorbus aria, Acer pseudoplatanus, Fagus sylvatica and Taxus baccata are important elements of temperate mountain forests, which do not reach thermally equivalent northern latitudes for unknown reasons.

In 2010, we launched the Global Index of Vegetation-Plot Databases (GIVD; http://www.givd.info), an internet-based resource offering metadata of existing electronic vegetation databases. On 11 May 2012, 182 databases containing more than 2.8 million non-overlapping vegetation plots had been registered in GIVD. The majority of these plots were from European databases (123 databases, 1.87 million plots). The oldest plot record dated from 1864, but the vast majority of the plots had been collected since 1970. Most of the plots had areas between 1 and 1,000 m2. A total of 68 databases also stored time series and/or nested-plot data. The vegetation-plot data registered in GIVD constitute a major resource for biodiversity research, not only through the large number of species occurrence records, but especially due to the storage of species co-occurrence information, complemented with site-specific structural data and plot-based environmental data. The increased ease of discovering and accessing such datasets, owing to their registration in GIVD, offers significant opportunities for large-scale studies in areas such as community ecology, macroecology, and global-change research. The results from such studies could be very important for nature conservation practice and policy.

The database BERGWALD (GIVD ID EU-DE-002), an electronic repository for vegetation plot data from forests and related vegetation in the Bavarian Alps (Germany), is presented. Created in 1995, the database has been intensively used for the classification and mapping of vegetation and site types, for calibrating and evaluating plant indicator values, and for analysing patterns of plant species richness. Hosted at the University of Applied Sciences in Freising, Bavaria, the data are available for collaborative re

WINALPecobase (GIVD ID EU-DE-003) is an ecological database of mountain forest plots in the Bavarian Alps (Germany). Created in 2009, the database features the following characteristics: (1) 1,505 georeferenced forest releves with concomitant soil profile descriptions, (2) placement across the whole study area (ca. 4,600 km2) according to a design that combines systematic and stratified sampling, (3) consistent standards for vegetation and soil inventory, and (4) extensive quality control of the database. The database is available for collaborative research.

Questions: Can forest site characteristics be used to predict Ellenberg indicator values for soil moisture? Which is the best averaged mean value for modelling? Does the distribution of soil moisture depend on spatial information? Location: Bavarian Alps, Germany. Methods: We used topographic, climatic and edaphic variables to model the mean soil moisture value as found on 1505 forest plots from the database WINALPecobase. All predictor variables were taken from area-wide geodata layers sothat the model can be applied tosome 250 000 ha of forest in the target region. We adopted methods developed in species distribution modelling to regionalize Ellenberg indicator values. Therefore, we use the additive georegression framework for spatial prediction of Ellenberg values with the R-library mboost, which is a feasible way to consider environmental effects, spatial autocorrelation, predictor interactions and non-stationarity simultaneously in our data. The framework is much more flexible than established statistical and machine-learning models in species distribution modelling. We estimated five different mboost models reflecting different model structures on 50 bootstrap samples in each case. Results: Median R 2 values calculated on independent test samples ranged from 0.28 to 0.45. Our results show a significant influence of interactions and nonstationarity in addition to environmental covariates. Unweighted mean indicator values can be modelled better than abundance-weighted values, and the consideration of bryophytes did not improve model performance. Partial response curves indicate meaningful dependencies between moisture indicator values and environmental covariates. However, mean indicator values 6.0 could not be modelled correctly, since they were poorly represented in our calibration sample. The final map represents high-resolution information of site hydrological conditions. Conclusions: Indicator values offer an effect-oriented alternative to physicallybased hydrological models to predict water-related site conditions, even at landscape scale. The presented approach is applicable to all kinds of Ellenberg indicator values. Therefore, it is a significant step towards a new generation of models of forest site types and potential natural vegetation.