The Environmental Impact Classification for Alien Taxa (EICAT) classifies the impacts caused by alien species in their introduced range in standardised terms across taxa and recipient environments. Impacts are classified into one of five levels of severity, from Minimal Concern to Massive, via one of 12 impact mechanisms. Here, we explain revisions based on an IUCN-wide consultation process to the previously-published EICAT framework and guidelines, to clarify why these changes were necessary. These changes mainly concern: the distinction between the two highest levels of impact severity (Major and Massive impacts), the scenarios of the five levels of severity for the hybridisation and disease transmission mechanisms, the broadening of existing impact mechanisms to capture overlooked mechanisms, the Current (Maximum) Impact, and the way uncertainty of individual impact assessments is evaluated. Our aim in explaining this revision process is to ensure consistency of EICAT assessments, by improving the understanding of the framework.

中文翻译：

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改进外来生物群的环境影响分类（EICAT）：对框架和准则的修订摘要

外来生物群的环境影响分类（EICAT）在引入的范围内，将外来物种的影响以标准化的术语在整个生物分类群和接收者环境中分类。通过12种影响机制之一，影响分为严重程度从最小关注到严重的五个级别之一。在这里，我们解释了基于IUCN范围的磋商过程对先前发布的EICAT框架和指南进行的修订，以阐明为什么需要进行这些更改。这些变化主要涉及：影响严重性的两个最高级别（重大和大规模影响）之间的区别，杂交和疾病传播机制的五个严重性级别的场景，扩大现有的影响机制以捕获被忽视的机制，当前（最大）影响，以及评估个人影响评估不确定性的方式。我们解释此修订过程的目的是通过增进对框架的理解，确保EICAT评估的一致性。