Alien plants of Europe: introduction pathways, gateways and time trends.

Building and managing large datasets of alien species is crucial to research, management and control of biological invasions. To this end, the European Alien Species Information Network (EASIN) platform aggregates, integrates and harmonizes spatio-temporal data regarding alien species in Europe, including both invasive and non-invasive alien species. These data are stored in the EASIN Geodatabase after their harvesting from relevant sources in the frame of a global and European databases partnership and scientific literature. The ownership of the data remains with its source, which is properly cited and linked. The process of data harvesting is performed through the EASIN Data Broker system, which retrieves the information related to alien species data in Europe and stores them in a normalized database structure. Data are subsequently refined through validation, cleansing and standardization processes and finally stored in the EASIN Geodatabase. All data are finally visualized and shown in occurrence maps at different levels of spatial visualization. Analysis of the data contained in the EASIN Geodatabase through flexible web services offered by the system has already provided useful input in scientific works and policies on biological invasions. Data from European Union (EU) member state official surveillance systems, within the framework of the EU Regulation 1143/2014 on Invasive Alien Species, are expected to contribute to the update of the EASIN Geodatabase. In addition, data from citizen science initiatives will further enrich the Geodatabase after appropriate validation. In this article we describe and discuss the technical aspects, data flow and capabilities of the EASIN Geodatabase.

The European Alien Species Information Network (EASIN) was launched in 2012 by the European Commission to facilitate the exploration of existing alien species information and to assist the implementation of European policies on biological invasions. At the core of EASIN, there is an inventory of all known alien and cryptogenic species in Europe (the EASIN Catalogue, herein published), which includes relevant information, such as taxonomic classification, pathways of introduction, year and country of first introduction. Spatial records of species occurrence in Europe are stored in the EASIN geo-databases, integrating data from many data providers and the literature. All this information is publicly available through a widget framework, providing easy to use and flexible tools for searching and mapping. The EASIN datasets have been used for pan-European or regional assessments of pathways and gateways of alien invasions, towards the fulfilment of the related targets of the Convention on Biological Diversity and of European policies. Moreover, in support of the new EU Regulation on the prevention and management of the introduction and spread of invasive alien species in Europe, an Early Warning and Rapid Response System is being developed by EASIN.

Ecological impact of phytoinvasions in Ukraine

The European Alien Species Information Network (EASIN; http://easin.jrc.ec.europa.eu) aims to facilitate the exploration of existing alien species information from distributed sources through a network of interoperable web services, and to assist the implementation of European policies on biological invasions. The network allows extraction of alien species information from online information systems for all species included in the EASIN catalogue. This catalogue was based on an inventory of reported alien species in Europe that was produced by reviewing and standardizing information from 43 online databases. It includes information on taxonomy, synonyms, common names, pathways of introduction, native range in Europe, and impact. EASIN catalogue entails the basic information needed to efficiently link to existing online databases and retrieve spatial information for alien species distribution in Europe. Using search functionality powered by a widget framework, it is possible to make a tailored selection of a subgroup of species based on various criteria (e.g., environment, taxonomy, pathways). Distribution maps of the selected species can be produced dynamically and downloaded by the user. The EASIN web tools and services follow internationally recognized standards and protocols, and can be utilized freely and independently by any website, while ownership of the data remains with its source, which is properly cited and linked.

Invasive alien species (IAS) are a key driver of global biodiversity loss. Reducing their spread and impact is a target of the Sustainable Development Goals (SDG target 15.8) and of the EU IAS Regulation 1143/2014. The use of citizen science offers various benefits to alien species’ decision-making and to society, since public participation in research and management boosts awareness, engagement and scientific literacy and can reduce conflict in IAS management. We report the results of a survey on alien species citizen science initiatives within the framework of the European Cooperation in Science and Technology (COST) Action Alien-CSI. We gathered metadata on 103 initiatives across 41 countries, excluding general biodiversity reporting portals, spanning from 2005 to 2020, offering the most comprehensive account of alien species citizen science initiatives on the continent to date. We retrieved information on project scope, policy relevance, engagement methods, data capture, data quality and data management, methods and technologies applied and performance indicators such as the number of records coming from projects, the numbers of participants and publications. The 103 initiatives were unevenly distributed geographically, with countries with a tradition of citizen science showing more active projects. The majority of projects were contributory and were run at a national scale, targeting the general public, alien plants and insects, and terrestrial ecosystems. These factors of project scope were consistent between geographic regions. Most projects focused on collecting species presence or abundance data, aiming to map presence and spread. As 75% of the initiatives specifically collected data on IAS of Union Concern, citizen science in Europe is of policy relevance. Despite this, only half of the projects indicated sustainable funding. Nearly all projects had validation in place to verify species identifications. Strikingly, only about one third of the projects shared their data with open data repositories such as the Global Biodiversity Information Facility or the European Alien Species Information Network. Moreover, many did not adhere to the principles of FAIR data management. Finally, certain factors of engagement, feedback and support, had significant impacts on project performance, with the provision of a map with sightings being especially beneficial. Based on this dataset, we offer suggestions to strengthen the network of IAS citizen science projects and to foster knowledge exchange among citizens, scientists, managers, policy-makers, local authorities, and other stakeholders.

The European Alien Species Information Network (EASIN) was created with the aim to provide easy access to accurate information on alien species in Europe. EASIN allows the retrieval of spatial information from existing online data providers in order to produce integrated georeferenced distribution maps of alien species in Europe. In November 2012, a new data provider, the Ellenic Network on Aquatic Invasive Species (ELNAIS), joined EASIN; this has significantly increased the available georeferenced information on marine/estuarine alien species in Greek waters. Here, we use maps created by EASIN to show differences in patterns of distribution in Greece for the most abundant Phyla of marine alien species - Mollusca, Arthropoda, Chordata and Annelida. We also show that the two main pathways of introduction of marine alien species (Lessepsian migration and Shipping) are related to different patterns of species spatial distribution in Greece. Overall, the tools provided by EASIN can greatly aid scientists and policy makers in obtaining high quality information on marine alien species in Greece, especially after the association with ELNAIS.

The European Alien Species Information Network (EASIN) was created with the aim to provide easy access to accurate information on alien species in Europe. EASIN allows the retrieval of spatial information from existing online data providers in order to produce integrated georeferenced distribution maps of alien species in Europe. In November 2012, a new data provider, the Ellenic Network on Aquatic Invasive Species (ELNAIS), joined EASIN; this has significantly increased the available georeferenced information on marine/estuarine alien species in Greece. Here, we use maps created by EASIN to show differences in patterns of distribution in the Greek Seas for the most abundant Phyla of marine alien species - Mollusca, Arthropoda, Chordata and Annelida. We also show that the two main pathways of introduction of marine alien species (Lessepsian migration and Shipping) are related to different patterns of species spatial distribution in Greece. Overall, the tools provided by EASIN can greatly aid scientists and policy makers in obtaining high quality information on marine alien species in Greece, especially after the association with ELNAIS.

The European Alien Species Information Network (EASIN) was created with the aim to provide easy access to accurate information on alien species in Europe. EASIN allows the retrieval of spatial information from existing online data providers in order to produce integrated georeferenced distribution maps of alien species in Europe. In November 2012, a new data provider, the Ellenic Network on Aquatic Invasive Species (ELNAIS), joined EASIN; this has significantly increased the available georeferenced information on marine/estuarine alien species in Greek waters. Here, we use maps created by EASIN to show differences in patterns of distribution in Greece for the most abundant Phyla of marine alien species - Mollusca, Arthropoda, Chordata and Annelida. We also show that the two main pathways of introduction of marine alien species (Lessepsian migration and Shipping) are related to different patterns of species spatial distribution in Greece. Overall, the tools provided by EASIN can greatly aid scientists and policy makers in obtaining high quality information on marine alien species in Greece, especially after the association with ELNAIS.

AimTo examine how native plant native communities, environment and geography are associated with alien plant species invasion in tropical island forests.LocationFour US national parks in Hawai'i and American Samoa.MethodsWe analysed the richness, coverage and composition of alien plant species communities located across 204 plots, five islands and two archipelagos. We used generalized linear mixed‐effects models and generalized dissimilarity models to determine the relative importance of native plant species communities (richness, structure and composition), environment (temperatures, precipitation, and soil age) and geography (elevation, geographical distance between plots, identity of islands and archipelagos) on alien plant species communities.ResultsAlien plant species were found in >90% of plots with on average four species covering ~15% of the understorey. Variation in alien species richness and coverage was primarily explained by archipelago and island identity and elevation. Plots located on younger islands tended to exhibit higher richness and coverage of alien plants. Native tree density and canopy height were negatively correlated with alien species coverage but not with alien species richness. Elevation was negatively correlated with both the richness and coverage of alien species. Differences in elevation, mean annual precipitation and geographical distances explained about 40% of the observed spatial turnover in alien species composition with differences in elevation being the main driver. Turnover in alien species composition was weakly correlated with turnover in native species.Main conclusionsIn the studied islands, higher elevations seem to be relatively spared from alien species invasion so far. However, our results suggest that the negative effect of elevation on alien species coverage may be larger than on alien species richness. Maintenance of tall and dense canopy may limit the coverage of alien species but not the number of alien species. Our results also support that alien species invasion may be particularly high on isolated archipelagos and younger islands.

Invasive process of alien species is affected by not only the invaded habitats, but also the surrounding landscape matrix. Understanding the effects of landscape matrix on alien species is of great significance for controlling invasive alien species. We surveyed plant communities along the water-level fluctuating zone (WLFZ) of the Three Gorges Reservoir. Invasive status of alien plant species was evaluated. Totally 10 spatial scales of the surrounding landscape matrix in the scope of 2000 m (including WLFZ) were classified, and 14 landscape indices were applied to analyze the landscape matrix composition and configuration. Using the principal component analysis and correlation analysis, the effects of landscape matrix on the alien invasive plant species and associated scale effect were tested. Results showed that a total of 42 alien invasive plant species were found in the WLFZ, belonging to 17 families and 36 genera. Fuling was a dividing place to differentiate invasive species distribution. The number of the alien invasive species between Fuling and the Three Gorges Dam was found more than that between Fuling and Jiangjin. For the all scales (within 2000 m). The higher the landscape matrix fragmentation was, the more difficult the alien species invading. The higher landscape connectivity was, the easier the alien species invading. The effects of landscape matrix composition and configuration on the invasive plant diversity at large scales (1200-2000 m) was more significant than those at small scales (200-1000 m), in which landscape matrix composition and configuration at 1200-1400 m showed the strongest effect, demonstrating a significant spatial scale effect. Different invasive plant species showed the scale effects of landscape matrix composition and configuration. At all scales, Xanthium strumarium and Bidens frondosa showed weak correlations with landscape indices, but Bidens tripartita and Erigeron canadensis showed strong correlations. Landscape matrix was closely related to invasive plant species, and demonstrated a significant scale effect. The alien invasive plant species could be traced to the landscape matrix at large scales. Grassland and forest patches at the small scales could be used as the 'stepping stone' for the alien species transiting before they arrived at the WLFZ. In order to control alien plants in the WLFZ, land-use management and optimization should be strengthened at different scales of landscape matrix on the basis of enhancement of habitat management. A diversified comprehensive control for alien species should thus be taken into account.

Summary Preventing the arrival of invasive alien species (IAS) is a major priority in managing biological invasions. However, information on introduction pathways is currently scattered across many data bases that often use different categorisations to describe similar pathways. This hampers the identification and prioritisation of pathways to meet the main targets of recent environmental policies. Therefore, we integrate pathway information from two major IAS data bases, IUCN's Global Invasive Species Database (GISD) and the DAISIE European Invasive Alien Species Gateway, applying the new standard categorisation scheme recently adopted by the Convention on Biological Diversity (CBD). We describe the process of mapping pathways from the individual data bases to the CBD scheme and provide, for the first time, detailed descriptions of the standard pathway categories. The combined data set includes pathway information for 8323 species across major taxonomic groups (plants, vertebrates, invertebrates, algae, fungi, other) and environments (terrestrial, freshwater, marine). We analyse the data for major patterns in the introduction pathways, highlighting that the specific research question and context determines whether the combined or an individual data set is the better information source for such analyses. While the combined data set provides an improved basis for direction‐setting in invasion management policies on the global level, individual data sets often better reflect regional idiosyncrasies. The combined data set should thus be considered in addition to, rather than replacing, existing individual data sets. Pathway patterns derived from the combined and individual data sets show that the intentional pathways ‘Escape’ and ‘Release’ are most important for plants and vertebrates, while for invertebrates, algae, fungi and micro‐organisms unintentional transport pathways prevail. Differences in pathway proportions among marine, freshwater and terrestrial environments are much less pronounced. The results also show that IAS with highest impacts in Europe are on average associated with a greater number of pathways than other alien species and are more frequently introduced both intentionally and unintentionally. Synthesis and applications. Linking data bases on invasive alien species by harmonising and consolidating their pathway information is essential to turn dispersed data into useful knowledge. The standard pathway categorisation scheme recently adopted by the Convention on Biological Diversity may be crucial to facilitate this process. Our study demonstrates the value of integrating major invasion data bases to help managers and policymakers reach robust conclusions about patterns in introduction pathways and thus aid effective prevention and prioritisation in invasion management.

Biological invasions, resulting from human activities, exert substantial impacts on ecosystems worldwide. This review focuses on marine invasive alien species (IAS) in Europe, examining the current state, proposing strategies to address the problem, and offering recommendations for enhanced management. Effective management of biological invasions relies on accessible, accurate data to inform decision-making. Information systems such as the European Alien Species Information Network (EASIN), Aquatic Non-Indigenous and Cryptogenic Species (AquaNIS), and World Register of Introduced Marine Species (WriMS) provide comprehensive databases on IAS, but their sustainability requires long-term maintenance, continuous updates, and support. Most countries lack specific monitoring programs for marine IAS, and standardization and improvement of monitoring methods are needed. Port monitoring plays a vital role in the early detection of new arrivals, and recent advancements in molecular techniques show promise for effective IAS monitoring. Risk screening tools are commonly employed to rank taxa based on their invasiveness potential in European regions, but variations in protocols can yield inconsistent results. European impact assessments highlight resource competition, novel habitat creation, and predation as primary mechanisms for negative impacts on biodiversity, while the creation of novel habitats represents a key mechanism for positive impacts. Preventing IAS introductions is critical, and measures such as ballast water treatment systems are implemented to reduce the likelihood of marine introductions. However, understanding introduction pathways remains uncertain for many IAS. Eradication and control efforts for marine IAS have limited success, emphasizing the need for enhanced biosecurity measures. Climate change, especially ocean warming, can intensify IAS impacts on native species and ecosystems. In climate change hotspots, some tropical aliens may, however, compensate for the loss of thermally sensitive natives with similar traits. Therefore, it is imperative to consider the interactions between climate change and IAS in developing effective management and conservation strategies. Enhancing IAS management in Europe entails i) securing adequate funding, ii) expanding the list of IAS of Union Concern to adequately cover marine invasions, iii) learning from countries with successful biosecurity practices, iv) sustaining information systems, v) improving monitoring and early warning systems with innovative technologies, vi) enhancing prediction models, vii) conducting integrated impact assessments and mapping cumulative IAS impacts, and vii) considering the potential benefits of IAS in ecosystem functioning and services.

潮虫消耗木本植物凋落物的可选择性试验

Insights into ecological drivers of alien plant invasions can be gained through comparative studies of growth and fecundity of invasive alien plants versus those of co‐occurring non‐invasive alien plants and native plants across environmental conditions in common garden settings. Habitats that harbour alien plant species in many ecosystems globally are presently experiencing light pollution resulting from artificial light at night (ALAN) and increased rates of nutrient enrichment of the soil. However, the potential interactive effects of ALAN and nutrient enrichment on invasiveness of alien plant species remain unknown. Here, we performed a common‐garden experiment to test the interactive effects of ALAN and soil nutrient enrichment on the growth of a random set of ten alien (five invasive and five non‐invasive naturalized) and seven co‐occurring native ornamental plant species that are commonly cultivated within urban and peri‐urban areas of Nairobi city in Kenya. We predicted that a simultaneous increase in photoperiod via ALAN and nutrient enrichment will favour growth of invasive alien plant species over that of non‐invasive alien and native plant species. We grew the 17 plant species under natural daylight (ALAN−) versus natural daylight followed by ALAN (ALAN+) and fully crossed with two levels of nutrient enrichment (low vs. high) and competition (competition vs. no‐competition against a native plant Ocimum gratissimum ) treatments. Under simultaneous high‐nutrient and no‐competition treatments, ALAN enhanced mean total biomass of invasive and non‐invasive naturalized alien species by 61.1% and 131.4%, respectively but decreased that of native plant species by 34%. In contrast, under simultaneous high‐nutrient and competition treatments, ALAN enhanced mean total biomass of invasive alien plant species by 68.6% and that of non‐invasive naturalized alien species by 51.9% and native species by 35.4%. High‐nutrient treatment enhanced flower formation more strongly in invasive and non‐invasive naturalized alien plants than in native plants. The invasive and non‐invasive naturalized alien species grew taller than native species across the light, nutrient, and competition treatments. Synthesis : The present findings suggest that light pollution and nutrient enrichment may jointly confer growth advantage to invasive alien plant species over that of co‐occurring native plant species and enhance invasiveness of alien plant species.

The number of alien species arriving within new regions has increased at unprecedented rates. Managing the pathways through which alien species arrive and spread is important to reduce the threat of biological invasions. Harmonising information on pathways across individual sectors and user groups is therefore critical to underpin policy and action. The European Alien Species Information Network (EASIN) has been developed to easily facilitate open access to data of alien species in Europe. The Convention on Biological Diversity (CBD) Pathway Classification framework has become a global standard for the classification of pathways. We followed a structured approach to assign pathway information within EASIN for a subset of alien species in Europe, which covered 4169 species, spanning taxonomic groups and environments. We document constraints and challenges associated with implementing the CBD Pathway Classification framework and propose potential amendments to increase clarity. This study is unique in the scope of taxonomic coverage and also in the inclusion of primary (independent introductions to Europe) and secondary (means of dispersal for species expansion within Europe, after their initial introduction) modes of introduction. In addition, we summarise the patterns of introduction pathways within this subset of alien species within the context of Europe. Based on the analyses, we confirm that the CBD Pathway Classification framework offers a robust, hierarchical system suitable for the classification of alien species introduction and spread across a wide range of taxonomic groups and environments. However, simple modifications could improve interpretation of the pathway categories ensuring consistent application across databases and information systems at local, national, regional, continental and global scales. Improving consistency would also help in the development of pathway action plans, as required by EU legislation.