Urbanization is a dominant driver of global landscape transformation, profoundly reshaping biodiversity patterns and ecosystem stability. Contemporary landscapes are increasingly characterized by intensive human intervention, leading to the homogenization of rural environments and the decline of species-rich habitats. In this context, a growing body of research (e.g. Aronson et al. 2017) demonstrates that urban green spaces can host biodiversity levels comparable to, or even exceeding, those in surrounding agricultural landscapes. Cities thus emerge as important refugia for a wide range of plant and animal species, including taxa of conservation concern. Particular attention has recently been given to spontaneous and semi-cultural ecosystems, such as ruderal sites, brownfields, and other forms of “novel urban nature”, which can support high habitat heterogeneity and unique species assemblages (Bonthoux and Chollet 2024, Kowarik and Lippe 2018). At the same time, integrating urban biodiversity into spatial planning remains a key challenge. Our study builds on these perspectives by addressing urban green spaces as socioecological systems shaped by both ecological processes and human perceptions. We present preliminary results from an interdisciplinary research project conducted in Prague, Czech Republic, combining ecological field data with sociological insights. First, we report findings from a quantitative survey examining how residents perceive different types of urban nature, from intensively managed urban green spaces (e.g. ornamental parks) through semi-natural habitats (e.g. urban forests and protected areas) to ruderal, successional, and unmanaged sites with spontaneous vegetation, with emphasis on biodiversity, aesthetics, and recreational use. The results reveal differentiated and often ambivalent attitudes, with increasing appreciation for less regulated, “spontaneous” green spaces alongside traditionally managed parks. Second, we introduce the BASALS method (Biotic And Social Assessment of Landscape Segments), a novel approach for quantifying biotic-social interactions. The method integrates ecological and social parameters into composite indices that capture habitat diversity and socioecological value across urban sites, including both protected areas as well as sites designated for development or transformation. Within the BASALS framework, we mapped the distribution of alien plants and assessed their contribution to plant species diversity in different types of urban landscapes. By linking biodiversity patterns, invasion dynamics, and public perception, the study contributes to a more nuanced understanding of urban ecosystems and supports the integration of spontaneous vegetation into urban planning and the development of green infrastructure strategies.

Alien trees reshape belowground fungal communities, but the factors governing the balance between mutualists and pathogens remain unclear. We tested whether residence time, mycorrhizal type, and biogeographical origin shape this balance, and whether alien stands differ from native vegetation. We sampled soils beneath 73 alien tree species in 48 chateau parks and native stands. Using ITS2 metabarcoding with guild assignment, we quantified ectomycorrhizal (ECM) and pathogen fungi and analysed predictors with multivariate models and binomial GLMMs, accounting for spatial structure and covariates. Symbiotic fungal community composition varied with origin, phylogenetic group and mycorrhizal type. With increasing residence time, ECM alien trees showed higher ECM fungal richness and relative abundance; whereas, contrary to enemy accumulation expectations, pathogen richness and relative abundance declined. Alien arbuscular mycorrhizal (AM) trees harboured more pathogens than ECM trees. Alien tree assemblages had a lower ECM fungal share, twice the pathogen relative richness, and threefold higher pathogen relative abundance than native assemblages. Residence time and mycorrhizal type are primary filters shaping belowground trajectories of alien trees, with biogeographical origin patterning community composition. Elevated pathogen loads in alien stands highlight spillover risks to neighbouring vegetation, informing risk assessment and monitoring of alien tree plantings.

Human-made habitats are hubs of plant invasions in new regions and the most important points of entry. We used the SynHab database, which allows us to analyse how habitat identity shapes plant naturalization patterns worldwide, based on 7,278 alien vascular plant species across 102 regions assigned to 14 basic habitat types, to demonstrate the importance of human-made habitats in plant invasions. They emerged as the most important global reservoir of naturalized plants. Among the six broad habitat groups, they harbour the largest cumulative number of naturalized species, with 5,488 species, far exceeding all other habitats. At the finer level, urban ruderal habitats are especially important, containing 4,890 naturalized species, while agricultural habitats contain 3,169. On average, 75.6% of the regional pool of naturalized aliens occurred in ruderal habitats and 49.0% in agricultural habitats. This makes urban and other heavily transformed human-dominated environments the clearest global centres of plant naturalization. Urban and ruderal habitats combine high propagule pressure, frequent disturbance, and broad resource availability, which together promote naturalization. Human-made habitats also show one of the steepest naturalization species accumulation curves, indicating high vulnerability to invasion when habitat area increases globally. Several drivers of naturalized species richness in human-made habitats are particularly relevant. The strongest was per capita GDP, showing a highly significant hump-shaped relationship and explaining 38% of the variation. Mean annual temperature also had a significant hump-shaped effect, while the maximum temperature of the warmest month and precipitation seasonality showed negative relationships, indicating that extreme heat and drought constrain naturalization. Minimum evapotranspiration was also negatively related to richness, while annual precipitation and precipitation of the wettest month showed significant quadratic effects. More generally across habitats, the paper highlights heat, drought stress, disturbance, and proxies of propagule pressure and human activity as major determinants of naturalized species richness. Thus, urban and other human-made habitats are not only the richest in naturalized species, but also among the clearest examples of how economic activity, human density, and environmental modification interact to drive global plant invasions.

Anthropogenic biodiversity decline threatens the functioning of ecosystems and the many benefits they provide to humanity1. As well as causing species losses in directly affected locations, human influence might also reduce biodiversity in relatively unmodified vegetation if far-reaching anthropogenic effects trigger local extinctions and hinder recolonization. Here we show that local plant diversity is globally negatively related to the level of anthropogenic activity in the surrounding region. Impoverishment of natural vegetation was evident only when we considered community completeness: the proportion of all suitable species in the region that are present at a site. To estimate community completeness, we compared the number of recorded species with the dark diversity-ecologically suitable species that are absent from a site but present in the surrounding region2. In the sampled regions with a minimal human footprint index, an average of 35% of suitable plant species were present locally, compared with less than 20% in highly affected regions. Besides having the potential to uncover overlooked threats to biodiversity, dark diversity also provides guidance for nature conservation. Species in the dark diversity remain regionally present, and their local populations might be restored through measures that improve connectivity between natural vegetation fragments and reduce threats to population persistence.

The Krkonoše Mountains are a unique ecological region facing increasing pressure from alien invasive and native expansive plant species, which threaten biodiversity and ecosystem stability. This study investigates the potential of UAV-based remote sensing for detecting and monitoring selected invasive species with focus on Lupinus polyphyllus. The primary objectives were (1) to acquire UAV multispectral data for several plots at multiple time points during the growing season in order to identify the best dates for the species detection, (2) to collect reference botanical data, (3) to test the suitability and reliability of mapping invasive/expansive species from UAV imagery using deep learning methods, and (4) to evaluate the effectiveness of various management interventions. High-resolution UAV imagery was processed using the SegUNet deep learning model, achieving classification accuracies up to 95.7%. The results indicated that species detection was most effective during flowering but also viable in spring due to distinct leaf morphology. One of the key findings of the analysis is that centimeter-range spatial resolution enables the detection and monitoring of Lupinus and other species during their growth and flowering stages, to a significant degree without requiring botanical input data. Our study confirms the applicability of UAV remote sensing for invasive species detection, offering a cost-effective and scalable solution for landscape-level monitoring in the future. Long-term monitoring will be essential for refining detection strategies, improving classification models, and testing the reliability, especially for detection after management interventions.

Plant invasion science has made a substantial progress in documenting the impacts of aliens, but comparisons with the impacts of native dominants are still rare. Further, the impacts on larger spatial scales remain poorly understood. We recorded the impacts of 10 native and nine invasive dominant plants in the Czech Republic on species richness and Shannon diversity by comparing communities with high vs. low cover of the dominant species. To estimate the impacts at the (i) population level and (ii) between-population level, we compared the Jaccard dissimilarity, nestedness and turnover of high- and low-dominance plots. Further, we calculated the Jaccard dissimilarity, nestedness and turnover between the high- and low-dominance plots within each population to express the impacts on species composition. We tested whether (i) native and invasive dominants affect the population- and between population levels of diversity by making the vegetation more homogenous; (ii) whether these effects differ between the native and alien dominants; and (iii) whether the impacts at different spatial levels are related. At the population level, high-dominance plots (with both native and alien dominants) showed higher nestedness and lower turnover compared to the low-dominance plots. Further, all plots with native dominants, both with high- and low dominance, showed higher similarity but lower nestedness than plots with alien dominants. Most importantly, high-dominance plots with native dominants were more similar to each other but showed marginally significantly lower nestedness compared to high-dominance plots with alien dominants. At the between-population level, high-dominance plots with native dominants showed a marginally significantly lower turnover compared to high-dominance plots with alien dominants. The differences in Jaccard dissimilarity, nestedness and turnover between the low- and high-dominance plots at the population level showed strong positive relations to low- and high-dominance differences at the between-populations level. Further, compositional impacts, expressed as the dissimilarity between high- vs. low-dominance plots, positively related to the plot-level impacts on Shannon diversity. Our results show that (i) both native and invasive dominants tend to reduce the diversity over larger areas and that the effect of native dominants may be even stronger, and (ii) the effects on plot-level richness and diversity cannot be easily extrapolated to larger scales but the impacts at the population- and between-populations levels are positively related.

Alien plant invasions have been systematically studied for more than half a century and we already have extensive scientific evidence of their negative role in the current biodiversity decline. Here we aim to draw attention to expansive plants, i.e. native plant species that exhibit similar ecological behaviour to invasive alien plants, being promoted by recent environmental changes. Some of them can also have various negative impacts on native plant communities and ecosystems. However, they have been much less studied than alien species. Our goal was to create an up-to-date catalogue of expansive species (including aggregates or subspecies where needed) in the Czech Republic, compare their functional traits and ecological strategies with non-expansive native species and provide a list of regions and habitats where they spread. We conducted a questionnaire survey, asking local experts to evaluate the expansive character of preselected species in 17 regions and 27 broadly defined habitat types (66 regional assessments). We critically revised these data and verified the distribution patterns. In total, we identified 126 expansive taxa (116 species, eight species aggregates and two subspecies, for simplicity referred to as species) from 43 families. The most represented were Poaceae (27 species, i.e. 21%, while only 7% in the native flora), Asteraceae (10 species; 8%) and Rosaceae (10; 8%). Our list comprises a heterogeneous group of plants, which tend to be taller and are more frequently polycarpic perennials than the non-expansive native species of the Czech flora. The highest numbers of expansive species were reported at middle elevations. Thirteen species were considered expansive in all regions: Aegopodium podagraria, Alopecurus pratensis, Anthriscus sylvestris, Artemisia vulgaris, Betula pendula, Calamagrostis epigejos, Dactylis glomerata, Elymus repens, Phalaris arundinacea, Poa trivialis, Rumex obtusifolius, Trifolium pratense and Urtica dioica. Expansive species were most frequently found in anthropogenic habitats, both non-forest (99 species) and woodlands (including plantations and clearings; 73), as well as in mesophilic meadows and pastures (64) and wet meadows (60). We hope that the presented list of expansive plants will trigger further research on them and their potential impacts on plant communities and other biota.

Great progress in cytotaxonomic research during the last decades indicated an importance of relationships between morphological features, geographical distribution of plants, and chromosome counts. This study is aimed to fill the gaps in our knowledge on Bolboschoenus chromosome numbers related to morphological differentiation of plants and their distribution worldwide. We counted gametophytic chromosome numbers in meiotic phase of plants, collected from localities worldwide during the period 1980–2013, and cultivated in an experimental garden in Průhonice. The chromosome numbers of seven species (Bolboschoenus affinis, B. caldwellii, B. grandispicus, B. medianus, B. novae-angliae, B. robustus and B. schmidii) were counted for the first time. All the studied Bolboschoenus taxa were divided into groups according to chromosome numbers, which were found to correspond to morphotypes formerly described. We have improved the taxonomic classification of some species. The relationship between chromosome counts and morphotypes appeared to be identical within some continents, and may indicate parallel evolution within the genus.

Alien tree species are considered both a threat to nature conservation and a base for forest management. We compiled species occurrences from biodiversity databases, forest inventories, and literature data. We modeled the availability of potential niches using the MaxEnt method and bioclimatic variables for current conditions, 2041-2060, and 2061-2080 periods. We used four climate scenarios: SSP126, SSP245, SSP370, and SSP485. The results confirm our hypotheses that, (i) coniferous species will contract, and deciduous trees will expand their climatic niche, (ii) a significant part of the areas where the studied species currently occur will be outside their climatic optimum in the coming decades; (iii) changes in the climatic optimum distribution will be greater in the 2041-2060 period than in 2061-2080. These predicted shifts are relevant for evidence-based management in sites already occupied by the studied alien trees. Our results are also relevant to the development of prevention and early detection measures in areas predicted to become climatically suitable for the studied species.

It has been established by research on plant invasions that soil biota and availability of nutrients affect the processes of alien species establishment and spread. So far, attention was mainly on alien invaders, although some native species (expansive), vigorously spread in human-influenced landscapes and also transform the habitats they colonize. Based on indirect gradient ordination analysis of vegetation relevés dominated by five native (Calamagrostis epigejos, Filipendula ulmaria, Phalaris arundinacea, Rubus idaeus, Urtica dioica) and five alien taxa (Impatiens glandulifera, Lupinus polyphyllus, Telekia speciosa, Reynoutria sp., Solidago canadensis agg.) in the Czech Republic, Central Europe, we identified pairs of species differing by origin (native vs alien) and growing in similar habitats. In the resulting 10 pairs, we tested the net effect of species origin on the following soil characteristics: (i) physical properties, (ii) nutrient availability, and (iii) biological activity. We found that the impact of alien invasive and native expansive species on soil cannot be explained simply by species' origin as a factor. Regardless of the origin, a statistically significant effect was recorded only for factors expressing nitrogen supply at the peak of the vegetation season and soil biological activity. Differences in impacts attributable to origin were only verified for individual pairs, being most pronounced between the alien Lupinus and its native counterparts Calamagrostis and Filipendula, and least between Solidago vs Calamagrostis, and Telekia vs Rubus. Both invasive alien and expansive native dominant plants can alter the rate of decomposition by changing the litter quality and availability of nutrients, mainly inorganic nitrogen. Therefore, management actions to preserve or restore diversity and mitigate the negative impacts of dominant species should be focused both on native and alien species.

Many phenological studies have shown that spring geophytes are very sensitive to climate change, responding by shifting flowering and fruiting dates. However, there is a gap in knowledge about climatic drivers of their distributions and range shifts under climate change. Here we aimed to estimate climate niche shifts for four widely distributed and common geophytes of the nemoral zone of Europe (Anemone nemorosa, Anemone ranunculoides, Convallaria majalis and Maianthemum bifolium) and to assess the threat level under various climate change scenarios. Using MaxEnt species distribution models and future climate change scenarios we found that the precipitation of the warmest quarter was the most important factor shaping their ranges. All species studied will experience more loss in the 2061-2080 period than in 2041-2060, and under more pessimistic scenarios. M. bifolium will experience the highest loss, followed by A. nemorosa, A. ranunculoides, and the smallest for C. majalis. A. ranunculoides will gain the most, while M. bifolium will have the smallest potential range expansion. Studied species may respond differently to climate change despite similar current distributions and climatic variables affecting their potential distribution. Even slight differences in climatic niches could reduce the overlap of future ranges compared to present. We expect that due to high dependence on the warmest quarter precipitation, summer droughts in the future may be particularly severe for species that prefer moist soils. The lack of adaptation to long-distance migration and limited availability of appropriate soils may limit their migration and lead to a decline in biodiversity and changes in European forests.

Rapidly increasing resources of citizen science databases (CS) collecting information on species occurrence are increasingly useful as a data source for global biodiversity research. The photos attached to records allow to verify the species identification and identify its phenological phase. We assessed CS data's usefulness in large-scale phenological research on temperate forest understory species, using a common and widely distributed in Europe: Anemone nemorosa. We analyzed 9804 photos from CS databases. We found 177 15' grid cells with >= 10 observations of flowering plants for bootstrap estimation of flowering onset and offset. We predicted flowering dates for the present and future climate according to Shared Socioeconomic Pathways averaged over four global circulation models for 2040-60 and 2060-80 across A. nemorosa natural range. The estimated magnitude of change in the flowering phenology for both future periods is comparable. The estimated flowering onset median was 24-41 days earlier while flowering offset median was 19-34 days earlier than predicted for the current climate. We estimated a flowering length median of up to 7 days longer than for current climatic conditions. The predicted changes in the phenology of flowering will not significantly change the duration of flowering but will accelerate onset of this phenophase by about one month. Our study showed that CS might provide a valuable dataset that allows for developing reliable models of plant phenology. It was possible due to a large sample size, resulting from species characteristics: flowering when wider audience is interested in searching spring indicators, easy identification and abundant occurrence. We demonstrated that using dataset of such spatiotemporal extent can cautiously be used for development of future predictions. Such approach allows for evaluating flowering phenology in the understory and to improve understanding the consequences of climate change for biodiversity and functioning of temperate ecosystems.

A complete list of all alien taxa ever recorded in the flora of the Czech Republic is presented as an update of the original checklist published in 2002. New data accumulated in the last decade are incorporated and the listing and status of some taxa are reassessed based on improved knowledge. Alien flora of the Czech Republic consists of 1454 taxa listed with information on their taxonomic position, life history, geographic origin (or mode of origin, distinguishing anecophyte and hybrid), invasive status (casual; naturalized but not invasive; invasive), residence time status (archaeophyte vs neophyte), mode of introduction into the country (accidental, deliberate), and date of the first record. Additional information on species performance that was not part of the previous catalogue, i.e. on the width of species’ habitat niches, their dominance in invaded communities, and impact, is provided. The Czech alien flora consists of 350 (24.1%) archaeophytes and 1104 (75.9%) neophytes. The increase in the total number of taxa compared to the previous catalogue (1378) is due to addition of 151 taxa and removal of 75 (39 archaeophytes and 36 neophytes), important part of the latter being the reclassification of 41 taxa as native, mostly based on archaeobotanical evidence. The additions represent taxa newly recorded since 2002 and reported in the national literature; taxa resulting from investigation of sources omitted while preparing the previous catalogue; redetermination of previously reported taxa; reassessment of some taxa traditionally considered native for which the evidence suggests the opposite; and inclusion of intraspecific taxa previously not recognized in the flora. There are 44 taxa on the list that are reported in the present study for the first time as aliens introduced to the Czech Republic or escaped from cultivation.

Question When evaluating forests in terms of their biodiversity, distinctiveness and naturalness, the affinity of the constituent species to forests is a crucial parameter. Here we ask to what extent are vascular plant species associated with forests, and does species' affinity to forests vary between European regions? Location Temperate and boreal forest biome of Northwestern and Central Europe. Methods We compiled EuForPlant, a new extensive list of forest vascular plant species in 24 regions spread across 13 European countries using vegetation databases and expert knowledge. Species were region-specifically classified into four categories reflecting the degree of their affinity to forest habitats: 1.1, species of forest interiors; 1.2, species of forest edges and forest openings; 2.1, species that can be found in forest as well as open vegetation; and 2.2, species that can be found partly in forest, but mainly in open vegetation. An additional "O" category was distinguished, covering species typical for non-forest vegetation. Results EuForPlant comprises 1,726 species, including 1,437 herb-layer species, 159 shrubs, 107 trees, 19 lianas and 4 epiphytic parasites. Across regions, generalist forest species (with 450 and 777 species classified as 2.1 and 2.2, respectively) significantly outnumbered specialist forest species (with 250 and 137 species classified as 1.1 and 1.2, respectively). Even though the degree of shifting between the categories of forest affinity among regions was relatively low (on average, 17.5%), about one-third of the forest species (especially 1.2 and 2.2) swapped categories in at least one of the study regions. Conclusions The proposed list can be used widely in vegetation science and global change ecology related to forest biodiversity and community dynamics. Shifting of forest affinity among regions emphasizes the importance of a continental-scale forest plant species list with regional specificity.

Milan Chytrý, Jiří Danihelka, Zdeněk Kaplan, Jan Wild, Dana Holubová, Petr Novotný, Marcela Řezníčková, Martin Rohn, Pavel Dřevojan, Vít Grulich, Jitka Klimešová, Jan Lepš, Zdeňka Lososová, Jan Pergl, Jiří Sádlo, Petr Šmarda, Petra Štěpánková, Lubomír Tichý, Irena Axmanová, Alena Bartušková, Petr Blažek, Jindřich Chrtek Jr., Felícia M. Fischer, Wen-Yong Guo, Tomáš Herben, Zdeněk Janovský, Marie Konečná, Ingolf Kühn, Lenka Moravcová, Petr Petřík, Simon Pierce, Karel Prach, Helena Prokešová, Milan Štech, Jakub Těšitel, Tamara Těšitelová, Martin Večeřa, David Zelený & Petr Pyšek

As a consequence of native tree species decline and distribution range contraction in Europe, acclimation of the non-native tree species at the edge of their distribution is gaining importance. Although non-native tree species may provide sustainable ecosystem services, as a potentially invasive species they may be a threat to local ecosystems as well. In Europe, black locust (Robinia pseudoacacia) a non-native species, seems to meet the condition of acclimation as a multi-generational process. The acclimatization, however, may have consequences not only for growth performance but also for the species? invasive potential. This study investigates the spatiotemporal pattern of secondary growth and climate sensitivity among six black locust stands along continentality gradient in Eastern Europe with the respect to bioclimatic conditions of the species distribution in Europe. Despite comparable bioclimatic conditions, climate sensitivity of black locust stands is highly variable, both temporally and spatially. The winter and spring temperatures are a key climatic driver of the growth pattern in southern and western Poland. Growth response to previous winter and current summer precipitation distinguished stands in western and eastern Poland. A significant increase in the mean annual temperature during the last 70 years likely triggered temporal instability of the black locusts? climate signal. In general, drought conditions were found to be the main limiting factor at the edge sites within the black locust gradient. Thus, the climate sensitivity of black locust stands reflects rather site-specific microclimatic conditions then bioclimatically-based clustering pattern. Despite climate-related limiting factors, black locust seems to be characterized by high potential for acclimatization to Eastern European climatic conditions, suggesting high invasive potential. Thus, the replacement of native species by black locust or the conversion of local habitats into monocultures for biomass production should not be recommended, while species management should follow proactive measures to reduce the risk of uncontrolled spread of the species. Divergent growth reaction of black locust stands implies high plasticity of secondary growth and thus high probability of acclimatization to future climate. Given the expected range expansion to the East in Europe, we call for expanding dendroclimatic studies to the areas of future species expansion in order to test its climatic and edaphic limitations. This seems to be crucial for formulating non-native species management strategies in line with sustainable forestry, preventing the uncontrolled expansion of the species that threatens vulnerable habitats.

Invasive alien plants are known to reduce the diversity of recipient communities. However, there is an ongoing debate on whether or not native dominant species have similar effects. To answer this question, we compared herbaceous dominant species of plant communities in central Europe, 10 of which were native and nine alien to this region. We sampled 5-16 populations per species, selected to reflect a gradient from a low to a high cover of the dominant species studied and include a range of typical habitats. To reveal the possible effect of scale, we sampled the vegetation in 4 x 4 m (large scale) and 1 x 1 m (small scale) plots. All vascular plant species and their percentage covers were recorded in each plot. LMM regressions models were used to relate the dominant species' cover to the richness and diversity of the plant community and ANCOVAs to test for differences between the impacts of native vs. invasive dominants. On the large scale, 17 dominants (nine native and eight invasive) significantly reduced community species richness, and seven (four native and three alien) decreased species diversity measured using the Shannon H' index. Reynoutria xbohemica, Calamagrostis epigejos and Phalaris arundinacea had the strongest negative impact on species richness, while Reynoutria xbohemica, Phalaris arundinacea and Urtica dioica had the strongest impact on species diversity H'; the results at the small scale were very similar. No significant differences in impacts were detected with regard to the origin of the dominant species when all 19 dominants were included in one model. Further, we used indirect gradient ordination analysis (DCA) to identify pairs of native and invasive dominants that grow in similar habitats and, thus, their impacts can be compared and tested for the effect of origin (native vs. alien). This procedure yielded 27 pairs in total, as some dominants occur in more than one type of habitat and could, therefore, be coupled with more than one species from the other group. At the large scale, native dominants had stronger impacts on species richness in three cases (Calamagrostis epigejos, Cirsium oleraceum and Phalaris arundinacea) and invasive dominants in two (Aster novi-belgii agg. and Rumex alpinus), making up 11.1% and 7.4% of the total number of pairs examined, respectively. Only the invasive dominants (Reynoutria xbohemica, Rumex alpinus) had stronger impacts on species diversity H', in four pairwise comparisons (14.8%). The differences were not significant at the small scale in all but one comparison. The results show that both native and invasive dominants can reduce the diversity of vegetation. To conserve biodiversity, measures should be adopted to mitigate not only the impacts of invasive species but also those of native dominants, spreading in the current landscape; this would be best achieved by promoting traditional management and land-use.

Robinia pseudoacacia is one of the most frequent non-native species in Europe. It is a fast-growing tree of high economic and cultural importance. On the other hand, it is an invasive species, causing changes in soil chemistry and light regime, and consequently altering the plant communities. Previously published models developed for the potential distribution of R. pseudoacacia concerned 2070, and were based mainly on data from Western and Central Europe; here we extended these findings and included additional data from Eastern Europe. To fill the gap in current knowledge of R. pseudoacacia distribution and improve the reliability of forecasts, we aimed to (i) determine the extent to which the outcome of range modeling will be affected by complementing R. pseudoacacia occurrence data with sites from Central, Southeastern, and Eastern Europe, (ii) identify and quantify the changes in the availability of climate niches for 2050 and 2070, and discuss their impacts on forest management and nature conservation. We showed that the majority of the range changes expected in 2070 will occur as early as 2050. In comparison to previous studies, we demonstrated a greater eastward shift of potential niches of this species and a greater decline of potential niches in Southern Europe. Consequently, future climatic conditions will likely favor the occurrence of R. pseudoacacia in Central and Northeastern Europe where this species is still absent or relatively rare. There, controlling the spread of R. pseudoacacia will require monitoring sources of invasion in the landscape and reducing the occurrence of this species. The expected effects of climate change will likely be observed 20 years earlier than previously forecasted. Hence we highlighted the urgent need for acceleration of policies aimed at climate change mitigation in Europe. Also, our results showed the need for using more complete distribution data to analyze potential niche models.