SSSI NH3 Critical Levels

This layer provides a Critical Level (CLe) for ammonia against which impacts on a SSSI should be assessed. The value is the lowest CLe for a feature on that site. The layer gives the SSSI name, SSSI code and ammonia Critical Level. The ammonia CLe can be: 1: a 1µg/m3 NH3 Critical Level indicates a SSSI has N-sensitive bryophytes/lichens as a feature or has bryophytes/lichens as key components of a habitat feature of that SSSI; 3: a 3µg/m3 NH3 Critical Level indicates a SSSI has N-sensitive vegetation, or has invertebrate features that are dependent on N-sensitive vegetation; NS: all features on a site are considered not to be particularly sensitive to ammonia; this does not mean that other aspects of a development will not have negative impacts on a SSSI, for example throug
h water pollution or disturbance.

本层提供了针对氨的临界级别（CLe），该级别用于评估对受保护特殊科学兴趣地（SSSI）的影响。该值是该地点特征的最低临界级别。该层提供了SSSI名称、SSSI代码和氨的临界级别。氨的CLe值包括：1：1µg/m³ NH3临界级别表明SSSI具有对氮敏感的苔藓/地衣作为特征，或苔藓/地衣是该SSSI栖息地特征的组成部分；3：3µg/m³ NH3临界级别表明SSSI拥有对氮敏感的植被，或拥有依赖于对氮敏感的植被的无脊椎动物特征；NS：该地点的所有特征均被认为对氨不特别敏感；这并不意味着其他发展方面不会对SSSI产生负面影响，例如通过水污染或干扰。