Seed germination is a key stage in a plant's life cycle, influencing regeneration from seed by determining the post-germination environment, plant fitness and evolutionary potential. Therefore, seed germination traits are expected to play a fundamental role in the naturalization of alien seed plants; yet broad-scale empirical evidence of this remains limited. Using seed germination data for 1146 native temperate European herbaceous species, we tested whether species that have become naturalized outside their native range differ from non-naturalized species in overall germinability (final germination proportion) and in their germination responses to six environmental cues across temperate, tropical dry and tropical humid macroclimatic zones of naturalization. We also assessed whether germinability and responses to these cues are associated with the geographic extent of naturalization, using a phylogenetically informed meta-analysis that integrates 18,596 standardized laboratory germination records with global naturalization data. Naturalization was a common phenomenon, with 60% of species having naturalized in temperate regions and over 30% having naturalized in tropical regions. Naturalized species showed consistently higher overall germinability, germination at lower temperatures and higher requirements for seed scarification compared to non-naturalized species, while other germination traits varied with the macroclimatic zone of naturalization. The extent of naturalization was also positively, though weakly, related to higher germinability and to the same germination traits that distinguished naturalized from non-naturalized species. Synthesis. This study provides global-scale evidence that the naturalization of European herbaceous species is related to specific germination traits acquired in the native range. Our findings indicate that traits such as high germinability, low stratification requirements and responsiveness to scarification act as preadaptations that facilitate naturalization by increasing opportunities for establishment. They also show that standardized laboratory germination tests using seeds sourced from native populations represent a cost-effective tool for improving global risk assessments and for predicting naturalization potential under climate change through alterations in regeneration from seed.

Invasive alien plants pose a significant threat to coastal ecosystems worldwide, with Carpobrotus taxa being among the most damaging. One of the most notable environmental consequences of plant invasions in coastal ecosystems is the modification of both abiotic and biotic soil properties. In this research, we investigated the impact of Carpobrotus taxa, representing distinct population genetic clusters in their native and non-native ranges, on soil abiotic characteristics, and the diversity of soil microorganisms. We sampled soils at 17 sites with Carpobrotus present vs absent, located in three regions: Southern Europe and California (non-native range) and South Africa (native range). We compared the pH, nutrient content, and diversity and composition of prokaryotic and fungal communities in soils from different regions as well as plots with and without Carpobrotus. We found substantial variation in soil abiotic properties and microbial diversity and composition between the studied regions, suggesting a strong influence of the regional context. Regardless of origin (i.e., native or nonnative) or the population genetic cluster, Carpobrotus presence caused significant changes in soil chemical properties and microbial communities but the type and direction of the changes varied across regions. For example, pH declined under Carpobrotus in California but not in the other regions, whereas % organic matter increased in the other regions but not in California. Understanding the context-dependent effects is crucial for predicting the ecological impacts of these invasive taxa.

Invasive plants are a major cause of diversity decline and altered ecosystem functioning in freshwater systems, with high connectivity making them particularly susceptible to new introductions and spread. While studies of plant invasion hotspots have used geopolitical regions to understand global patterns, freshwater plant invasions are better understood at the scale of basins. By combining the inventory of species in the Global Naturalized Alien Flora with aquatic habitat status of all those species and their global occurrence records, we analysed the richness of non-native freshwater plants found in freshwater basins worldwide. After accounting for basin area and sampling effort, we found that the pattern of freshwater plant hotspots differs from that of terrestrial plants. There are basins on all ice-free continents with higher-than-expected non-native freshwater plant richness, though there are relatively few such basins in Europe. Importantly, almost a third of all RAMSAR Convention wetland sites occur in basins with at least 10 non-native freshwater plant species. Our findings demonstrate that freshwater plant invasions may present a considerable risk to the conservation of key freshwater ecosystems on all continents, but better surveillance of wetland sites is needed to separate current invasion levels from future risk.

The character of invaded habitats provides a complex information about the ecology of naturalized aliens and suggests the type of processes associated with their establishment at a landscape level. While single-habitat affiliations are typically studied, the synergistic combinations of habitats occupied by species offer more detailed and complete information about plant naturalizations. We performed cluster analysis to reveal the similarity of 14 habitat categories, based on the composition of affiliated naturalized species; tested if the globally most represented habitat combinations occur more frequently than expected by random; tested if the species affiliated in a given combination of habitats are globally more successful, compared to species affiliated in the corresponding single habitats; and tested, if the frequency of the most represented habitat combinations differs between the Old World and New World and between the Northern and Southern hemisphere. cluster analysis to reveal the similarity of 14 habitat categories, based on the composition of affiliated naturalized species; tested if the globally most represented habitat combinations occur more frequently than expected by random; tested if the species affiliated in a given combination of habitats are globally more successful, compared to species affiliated in the corresponding single habitats; and tested, if the frequency of the most represented habitat combinations differs between the Old World and New World and between the Northern and Southern hemisphere. Preliminary results of the cluster analysis revealed predictable groupings of invaded habitats similar in environmental conditions, such as Open forests – Scrub, Aquatic – Wetlands, Dryland – Rocky, Agricultural – Ruderal clusters. However, we found that Human-maintained grasslands and Natural grasslands are occupied by very different suites of naturalized alien species. Globally, the combinations of human-disturbed habitats containing either Ruderal or Agricultural habitat occurred with a significantly higher frequency than expected at random and occupied more regions than those restricted to either habitat alone. This suggests that habitat generalism – specifically across anthropogenic disturbance regimes – is a key predictor of global invasion success. Biogeographic patterns in the habitat combinations frequencies differ between the Old World and New World and between the Northern and Southern hemisphere. The most overrepresented habitat combinations in the Old World and Northern hemisphere were Open forests – Ruderal habitats and Agricultural habitats – Ruderal habitats, respectively, reflecting a legacy of prolonged human settlement and intensive landscape modification in regions where modern invasions originated. In contrast, the most overrepresented combination in the New World was Human-maintained grasslands – Ruderal habitats, a pattern likely driven by the historical expansion of European-style pastoralism and livestock management. Further, the most overrepresented combination in the South was Forests - Ruderal habitats, which may be linked to human-induced disturbances of (semi-) natural vegetation.

While the influential role of scientific associations in shaping research fields is well recognized, their impact within the domain of invasion science remains underexplored. This review combines qualitative narrative with quantitative metrics to trace the development of Neobiota, the first European non-profit and non-governmental scientific association dedicated to the study of biological invasions. Since its foundation in 1999, the Neobiota network has aimed to foster scientific exchange and collaboration, advance and integrate research across all dimensions of invasion science, and disseminate findings to support evidence-based policies. Evolving rapidly from a German working group into Europe’s leading network for invasion science, Neobiota has united researchers and practitioners across disciplines, taxa, and national boundaries. In contrast to many other associations, Neobiota operates with a low-threshold, non-bureaucratic governance model, promoting inclusivity and cross-border engagement. We document how its biennial conferences—hosted in 12 European countries between 2000 and 2024—have supported thematic diversity (ranging from molecular biology to socio-economy), increasing international participation (9–47 countries globally), and active policy outreach. Thematically, the focus of research presented at conferences has shifted over time from ecological patterns and species inventories to environmental impacts, predictive modeling, management strategies, and socio-political dimensions of invasions. Trends in equity reveal progress toward gender parity among keynote speakers and session chairs. Neobiota has also supported the dissemination of knowledge through two publication platforms: the Neobiota series (2000–2008) and the open-access, peer-reviewed journal NeoBiota launched in 2011. This journal currently operates under an Editorial Board with 75 subject editors and a team of five Co-Editors-in-Chief. We conclude that over the past 25 years, Neobiota has been instrumental in building a cohesive and inclusive scientific community globally, advancing and disseminating interdisciplinary research on biological invasions, and informing policy, particularly in support of legal frameworks to prevent and mitigate the negative impacts of non-native species.

The savanna habitats often harbour abundant and species-rich bat communities. Whether they represent mere ad hoc assemblages of incidentally co-occurring forms or distinct entities integrated by locally specific adaptations and balanced resource partitionings is largely unknown, as are the natural drivers shaping community variation at different spatial scales. An extensive dataset (130,888 acoustic bat records from 31 acoustic parataxa) was collected in 60 plots across Kruger National Park (KNP), South Africa; the plots were located (i) at perennial rivers, (ii) at seasonal rivers, and (iii) on dry crests away from any water source. Besides the effect of water availability, distance to campsites, and microgeographic variation on bat community richness and structure, we found (i) extensive homogeneity in community structure at local, subregional, and regional scales contrasting to a mosaic from between-plot variation, (ii) absence of robust effects of environmental biotic and abiotic predictors on the distribution of individual acoustic parataxa and community variation, (iii) nearly identical pattern of habitat preferences in all community members approaching the centroid of KNP habitat variation, and (iv) an exceptionally high degree of community nestedness. These results suggest that the bat community of the KNP savanna biome represents a single entity consistently integrated with a network of coexistence relations that probably arose locally during a long savanna history.

Aim The intentional or unintentional transport of non-native plants is key to overcoming geographic barriers. However, it remains unclear whether such introduction pathways associate with overcoming environmental barriers, which is key for successful invasion. Here, we test how intentionality of introduction associates with niche breadth and niche harshness. Location Europe. Time Period 1914-2020. Major Taxa Studied 220 plant species. Methods Across > 60,000 invaded vegetation plots, we tested whether intentionality of introduction (intentional, unintentional, or both) and characteristics of non-native plants (native climatic niche breadth, growth form, dispersal syndrome, height, residence time) were associated with their niche breadth, quantified through habitats, climate, and co-occurring flora. We tested how the intentionality of introduction was associated with environmental harshness (drought, salinity, oligotrophy, and elevation), while accounting for land-cover and habitat types. Results Non-native plants introduced both intentionally and unintentionally had a broader habitat range, compared to non-native plants introduced only unintentionally. A broad climatic niche in the native range was associated with a broader invaded climatic niche, while a long residence time was associated with broader habitat and biotic niches. Intentional introduction was associated with the invasion of dry habitats and forests, whereas unintentional introduction was linked to the invasion of saline, high-elevation, and disturbed environments. Main Conclusions In addition to triggering invasions, the type of process responsible for introduction can partly explain how non-native plants overcome environmental barriers in the invaded range. The intentionality of introduction was associated with niche breadth only in terms of habitat range, while the association with niche harshness depended on the type of stress, which highlights the importance of integrative niche assessments. The relationship between intentionality of introduction and the invaded niche could relate to intentionality-specific differences in biological attributes (environmental tolerance, dispersal capacity, and preference for disturbance) and the introduction process (propagule pressure and residence time).

Biological invasions impose substantial ecological and socio-economic burdens, yet the global economic impacts of invasive plants remain incompletely quantified. Here, we provide the first comprehensive global synthesis of reported monetary costs associated with invasive plants using the InvaCost database. After data validation and filtering for highly reliable, observed estimates, we identified a total cost of US$ 361.8 billion in documented costs worldwide between 1960 and 2022, representing a conservative baseline of invasive plant impacts at global level. Costs were strongly uneven across taxa and regions, with a small number of species and families accounting for the vast majority of costs and North America dominating reported expenditures. Terrestrial environments and the agricultural sector bore the greatest economic burden, while damage costs exceeded more than three times those related to management, and preventive investments remained negligible. Annual costs increased markedly from the 1990s onward, reaching peak values exceeding US$ 50 billion in some years. Cumulative damage costs followed sigmoidal trajectories, indicating rapid escalation over recent decades and suggesting substantial long-term economic liabilities under business-as-usual conditions. Socio-economic context and country size were key predictors of reported costs, highlighting strong reporting and capacity biases. Despite the magnitude of documented impacts, plant invasion costs remain severely underestimated due to taxonomic, geographic and sectoral data gaps. Our synthesis reveals the scale, concentration and accelerating trajectory of invasive plant costs globally, underscoring the urgent need for improved reporting, proactive prevention and more effective management to limit future economic losses.

Invasive alien species (IAS) are a major driver of global biodiversity loss, generating substantial ecological, economic and social impacts. Prevention and early intervention are widely recognised as being more cost‑effective than long‑term management. As a result, IAS policy frameworks increasingly rely on predictive strategies and tools to guide prioritisation. Horizon scanning has emerged as a key approach, providing structured, forward‑looking assessments of IAS that are likely to arrive in a new area in the near future, establish invasive populations and cause harm. Despite widespread uptake of the method, there has, to our knowledge, been no global synthesis of how IAS horizon scanning exercises are conducted, how methodologies are developed, and what their potential policy implications are. Here, we present a global review of over 50 IAS horizon scanning exercises undertaken up to 2026, drawing on published and grey literature. We examine how horizon scans were designed across multiple taxonomic groups, geographic scales, regions and environments, evaluate their underlying objectives, such as informing policy and biosecurity, and review their recommendations. Our review shows that the number of horizon scans has been steadily increasing in recent years. Across the horizon scanning literature, terrestrial and freshwater environments were more frequently represented than marine systems, and exercises more often covered a range of taxonomic groups (including plants and animals) rather than focusing on a single group (e.g. invertebrates) alone. Furthermore, the majority of horizon scanning exercises to date have been undertaken in Europe, predominantly at a country level, although transnational- and regional‑level exercises have also been conducted. Impacts on native biodiversity were the dominant focus, although consideration of economic and human health impacts have been increasing in recent studies. Horizon scanning outputs are most often intended to inform biosecurity planning and policy implementation, including the prioritisation of species for further risk assessment and risk management. Most exercises follow a broadly consistent workflow: compilation of large species longlists; application of exclusion criteria to focus further effort and review; structured scoring of likelihood of arrival, establishment, spread and impact; and the application of consensus‑based prioritisation through expert elicitation and moderated group discussions. However, we identified variation in how species lists are compiled/generated, how climate or habitat suitability is assessed, which risk‑scoring frameworks are applied, and whether management feasibility or socio‑economic considerations are formally incorporated. Many studies report uncertainty associated with scoring the likelihood of arrival, establishment, and impact, particularly for understudied taxonomic groups and emerging pathways. Recurring challenges include inconsistent reporting of methods and assumptions, and limited evaluation of whether identified species inform regulatory or other action. We highlight the value of horizon scans for the effective prevention of IAS and discuss how greater standardisation of reporting and systematic evaluation could strengthen the policy impact, e.g. by facilitating the transfer of outcomes between ecologically similar regions and allowing for the upscaling of local results to larger geographic scales. Similarly, as horizon scanning practice expands, this might allow the integration of big data analytics and machine learning methods to identify emerging patterns, pathways, and taxonomic or functional trends associated with invasion risk. This could facilitate more data-driven, automated and rapid screening processes, improving the scalability and consistency of assessments, and strengthening proactive decision-making.

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.

Abstract Global megatrends are large–scale, long–term shifts that shape environmental and societal change and provide a novel lens for anticipating future biological invasions. Using expert elicitation, we assessed how 15 megatrends may influence the arrival, establishment, spread, and impact of alien plant invasions by 2050. Most megatrends were expected to increase invasion risks, particularly by accelerating species arrival and spread. Megatrends clustered into four gigatrends: Anthropocene, Digital, Societal, and Technology. In the Anthropocene, invasion threats will escalate through increased global trade and climate–driven range shifts. Digital driven e-commerce and misinformation further elevate risks, whereas an aging society reduces the Societal capacity for managing invasive plants. Despite advances in Technology potentially abating plant invasions through improved detection and control tools, significant adoption barriers remain. Invasion scientists must urgently help policymakers recognize that, although future megatrends will amplify plant invasions, decisive engagement can still steer trajectories toward mitigating this growing global threat.

Protected areas (PAs) are key for conserving biodiversity and can act as partial barriers against the regional spread of alien species. Yet, the number of invasive species and the magnitude of their impact on PAs are increasing globally, creating an urgent need to establish effective management actions. Increased public interest in biological invasions in PAs may lead to increased support for their management. To assess recent public interest, we extracted and analysed data from Twitter/X, which was one of the most popular microblogging social media platforms during the study period. Firstly, we extracted all tweets posted between 2010 and 2020 containing the scientific name of any plant species recorded as naturalised anywhere in the world, or the term ‘invasive species’, together with the name of any national park globally and the term ‘national park’. This approach allowed us to capture potential mentions of species across their native and non-native ranges. Mentions of species in their native ranges were identified and flagged in the dataset. Secondly, using Kruger National Park (i.e. one of the oldest and most widely known protected areas in the world) as a study case, we extracted all tweets posted in 2010–2020 containing the term ‘Kruger’ together with: (1) the scientific name of any of the 146 taxa recorded in the recently updated naturalised alien flora of the park, (2) the genus name of some of the most well-known naturalised plant species in the park, some of which also function as common names, and (3) the term ‘invasive species’. We found a very limited number of tweets. These results suggest that public engagement with the topic of invasive plant species in national parks on social media was limited during the study period. Conservation implications: Public awareness campaigns are needed to support successful management of plant invasions in protected areas globally.

Invasive animal species threaten ecosystems, biodiversity and human livelihoods. Behavioural traits such as boldness, exploratory tendencies, learning ability and social interactions are known to influence invasion success. Yet these behavioural traits remain underexplored due to challenges in observing behaviour across large spatial and temporal scales. The emerging field of iEcology-studying ecology using digital data such as online photos, videos, sounds and text, generated for other purposes-offers a novel and scalable approach for investigating invasive species behaviour. Here, we demonstrate the application of iEcology to uncover novel insights into the behaviour of invasive species, such as dominance over the native species, interactions with native species or increased tolerance to humans, all critical for assessing species' invasion potential and management. We also discuss challenges of applying iEcology to studying the behaviour of invasive animals and highlight the need for careful validation and complementary methods. Finally, we highlight ways and provide a workflow to maximise the potential of iEcology for advancing the study of invasive species behaviour. We advocate for integrating iEcology into invasion science to advance our understanding of animal behaviours accompanying invasion success and ultimately to support the monitoring, management and mitigation strategies of biological invasions. We argue that iEcology is best viewed as a complementary tool that enriches traditional behavioural ecology and invasion biology, enabling rapid, accessible insights into one of the most urgent ecological issues of our time.

Drivers of non-native plant success in drylands are poorly understood. Here we identify functional differences between dryland native and non-native perennial plants and assess how biotic, abiotic and anthropogenic factors shape the success of the latter. On the basis of plant community and functional trait data from 98 sites across 25 countries, we report a total of 41 non-native plant species at 31 sites. Non-natives tend towards faster growth strategies than natives. Non-native plant richness is higher at sites with greater grazing pressure and under environmental conditions associated with higher soil fertility, decomposition and fungal richness-conditions that tend to occur in less arid regions-and lower where native plant and herbivore richness are greater. Non-native plant cover correlates positively with grazing pressure and negatively with native plant richness. Taken together, our results suggest that non-native plant success in drylands is facilitated when high grazing pressure coincides with elevated resource availability. Such context-dependence of non-native plant success and linkages with native plant and herbivore diversity highlight the need for managing grazing and conserving biodiversity across the world's drylands.

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.

Grassland ecosystems are facing rapid and ongoing change driven by intensified land-use and accelerated climate change, highlighting the urgent need to understand their potential adaptation and response to environmental change. We analyzed data from 52 980 vegetation plots spanning all major grassland habitats in Europe (including alpine, rocky, sandy, saline, dry, mesic and wet grasslands). We quantified competitive (C), stress-tolerant (S), and ruderal (R) strategies for 7858 plant species based on key functional traits and mapped the spatial patterns of C-, S- and R-strategies across European grasslands. Using random forest models, we evaluated the relative importance of environmental factors in shaping these patterns and explored potential changes in the distribution of C-, S- and R-strategies under future climate scenarios. We further investigated how these strategies and their environmental drivers vary across grassland habitats. Our results revealed a clear biogeographical gradient in the distribution of C-, S- and R-strategies from predominantly stress-tolerant strategies in Mediterranean grasslands to greater representation of competitive and ruderal strategies in temperate regions. Climate and soil factors emerged as major drivers shaping these patterns at the continental scale. Projected responses to future climate change varied among regions: grasslands in the Atlantic and Continental regions were projected to decrease in C-strategy and increase in both S- and R-strategy representation, whereas grasslands in Arctic and boreal regions exhibited contrasting trends. Mediterranean grasslands were projected to undergo a transition from mainly R-strategy toward S-strategy species predominance. Furthermore, the strategy patterns and their key drivers differed among grassland habitats, with patterns largely reflecting habitat-specific environmental constraints. This study demonstrates the utility of Grime's CSR framework for characterizing broad-scale patterns of plant adaptive strategies across diverse grassland habitats. It highlights region- and habitat-specific differences in potential responses to future climate change, with implications for targeted grassland management and restoration.

Human influence is a key driver of plant invasions. Yet, invasion science has largely focused on ecological factors, often overlooking the human and social dimensions that shape the invasion process. The InvaSyn project aims to address this gap by identifying plant invasion syndromes that integrate these dimensions, ultimately improving our understanding of the context-dependent nature of biological invasions. To contribute to this aim, we draw on the Protected Areas and Invasive Alien Species (PROTIAS) database, developed within the SynHab project (www.synhab.com), which compiles data on the presence of naturalised alien plant species across nearly 1,500 protected areas (PAs) in more than 50 countries, encompassing approximately 5,000 alien taxa. Using novel culturomics approaches, we aim to characterise people's interest in and awareness of non-native plant species listed in the PROTIAS database by analysing Google Health Trends and Wikipedia. For this, we searched en.wikipedia articles associated with PROTIAS-listed PAs for content related to these non-native plant species. For each species, we quantified relative search volumes on Google Health Trends and pageviews on en.wikipedia. Furthermore, in each Wikipedia PA articles we examined the frequency of mentions, the context in which species appeared (e.g. introduction, impacts, management), and the level of engagement generated (e.g. the number of visits to species links). We then used these metrics to classify non-native species into groups with similar patterns of people’s interest and awareness (e.g. high engagement but limited search volume) using multidimensional scaling (MDS). Species-level analyses were also conducted to relate these metrics to naturalisation success, defined as the number of PROTIAS-listed PAs and GloNAF (Global Naturalised Alien Flora) regions from which a species has been reported. We hypothesise that certain types of plant invasions in PAs are shaped by distinct combinations of social and ecological factors that group into identifiable clusters (e.g. a species that attracts high public attention due to its substantial impact but has limited naturalisation success). Additionally, we recorded the frequency of mentions of other major drivers of global environmental change (e.g. pollution, fire, direct exploitation of species) in the Wikipedia PA articles, to contextualise how people's interest in plant invasions compares with attention to other conservation-related threats. By integrating the PROTIAS database with culturomics, this study aims to generate insights on the perception of plant invasions in PAs that can help guide conservation efforts.

Urban areas serve as hubs for non-native plant introductions, but the extent to which these introductions have homogenized city floras globally remains unexplored. We analyzed species inventories from 553 cities across six continents and show that non-native plants increase mean pairwise floristic similarity by ~50%, from a Jaccard index of 0.11 for native species alone to 0.16 when non-natives are included. Non-natives increase intracontinental similarity by 25%, but boost intercontinental similarity by 423%, due to intercontinental native floras sharing few species. City connectivity (indexed by air-travel frequency) amplifies non-native similarity more than native similarity, while geographic distance constrains native similarity more strongly, consistent with dispersal limitation. Contrary to our original hypothesis, climatic distance constrains non-native similarity as strongly as native similarity, confirming that climate is a hard environmental filter regardless of species’ origin. Meanwhile, urban socio-economic and physical features also affect native and non-native floristic similarity comparably. Regional analyses reveal pronounced asymmetries, with non-native species strongly homogenizing cities in Europe, North America, and Oceania, whereas Asian cities show weak intercontinental convergence. Decomposing similarity into ecological components reveals distinct mechanisms: homogenization between city pairs that involve European cities is dominated by species transfers (taxa native in one region but naturalized in another), reflecting colonial and trade legacies, whereas North American-Oceanian convergence is driven by a shared pool of widespread non-native species. These findings demonstrate that human-mediated plant movement has become a dominant force reshaping global urban flora, with effects modulated by connectivity, environmental filtering, and region-specific historical legacies.

Understanding physiological integration in invasive clonal plants is relevant to invasion biology because resource transfer across ramets may allow alien plants to buffer spatial heterogeneity in their introduced areas. However, experimental evidence across native and non-native ranges is limited. Here, we tested whether physiological integration provides greater performance benefits to Carpobrotus taxa in non-native than native ranges. We grew clonal fragments under controlled conditions from eleven populations representing different genetic clusters across their native and non-native ranges. Connected recipient ramets showed higher growth than severed ones, with increased ramet length, node number, Branching and Vigor Indices, while connected donor ramets showed reduced growth, indicating resource redistribution within the clone. Plants from non-native ranges exhibited overall higher growth-related traits and chlorophyll content, suggesting enhanced growth and stress tolerance across genetic backgrounds. These results indicate that physiological integration allows Carpobrotus taxa to overcome environmental heterogeneity by reallocating resources among ramets, promoting clonal growth and expansion, and potentially increasing competitive ability in non-native ranges. Our findings provide experimental evidence across multiple populations that physiological integration can promote the ecological success of clonal invaders.

Effective conservation of biodiversity, declining at unprecedented rate, requires not only monitoring of threatened species populations but also rapid detection of new incursions of alien species. However, traditional monitoring methods are costly, and citizen-science data is often geographically biased. iEcology, i.e. harnessing online digital data generated for purposes other than science (e.g. social media posts, photos, or online search behaviour), has been proposed as a tool to fill such biodiversity data gaps, especially in underrepresented regions. Despite growing interest, the full potential of iEcology for monitoring species distributions has not been systematically assessed. We systematically reviewed studies that used iEcology methods to obtain georeferenced species observation data, with specific focus on the representation of digital platforms, taxonomic groups, ecological realms (freshwater, marine, terrestrial) and geographic regions, as well as raw data availability. As a substantial proportion of the screened & reviewed studies focused on non-native species, we additionally assessed whether any reported impact information is relevant to Gloim (Global environmental impacts of plant invasions), our new project on global invasion impacts.