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.

中文翻译：

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将《生物多样性途径分类公约》适用于欧洲的外来物种

到达新区域的外来物种数量以前所未有的速度增长。管理外来物种到达和扩散的途径对于减少生物入侵的威胁很重要。因此，统一跨各个部门和用户群体的途径的信息对于支持政策和行动至关重要。建立欧洲外来物种信息网络（EASIN）的目的是轻松地促进对欧洲外来物种数据的开放访问。《生物多样性公约》途径分类框架已成为途径分类的全球标准。我们遵循一种结构化的方法，在EASIN中为欧洲的一部分外来物种分配了途径信息，该物种涵盖了4169个物种，涵盖了生物分类群和环境。我们记录了与实施《生物多样性公约路径分类》框架相关的制约因素和挑战，并提出了可能的修正案以提高清晰度。这项研究在分类学覆盖范围以及引入的主要模式（独立引入欧洲）和次要的（引入物种后在欧洲范围内扩散物种的传播方式）方面都是独特的。此外，我们总结了在欧洲范围内这一外来物种子集中的引入途径模式。根据分析，我们确认《生物多样性公约》的途径分类框架提供了一个健壮的，分级的系统，适用于引入外来物种并在广泛的生物分类群和环境中扩散的分类。然而，简单的修改可以改善途径类别的解释，确保在本地，国家，区域，大陆和全球范围内跨数据库和信息系统的一致应用。按照欧盟法律的要求，提高一致性还将有助于制定途径行动计划。