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SSSI guidelines

Rationale, Operational approach and criteria, Detailed guidelines for habitats and species groups.

Part Two of the guidelines is being revised.


The Guidelines for the Selection of Biological Sites of Special Scientific Interest (SSSIs) provide a consistent rationale for the evaluation and selection of biological SSSIs throughout Great Britain (the guidelines for the Selection of Geological and Physiographical SSSIs are published separately by JNCC). SSSIs are designated in accordance with the duties in law placed upon each of the country nature conservation bodies (CNCBs) to notify as a SSSI any area of land which, in its opinion, is of special interest by reason of any of its flora, fauna, geological, geomorphological or physiographical features. The Guidelines are intended primarily to help CNCB staff in the selection of biological SSSIs, but are also intended as a public statement of the selection principles for all interested parties.

Part 1 of the Guidelines sets out the general principles from which the evaluation and selection procedures have been developed and explains background issues and concepts. It deals with the broad operational approach and the criteria for SSSI evaluation and selection. Part 2 presents the detailed and specific guidance for each of the main habitat types and species groups.

A revision of Part 2 chapters is underway and as of February 2021 over half (about 60%) of the reviewed chapters have been published, and progress is being made with the rest. 

The revisions are being undertaken by staff in the country nature conservation bodies (CNCBs), who work together across the UK to revise and review the chapter under the leadership of one of the authors. JNCC carries out a further process of peer review, and the finished chapter is approved by JNCC's Joint Committee before being published.

The SSSI Biological Guidelines chapters are listed below. Where revisions are underway, the link is to the old version of the guidelines.


Part 1: Rationale, Operational Approach and Criteria for Site Selection

Part 1: Rationale, Operational Approach and Criteria for Site Selection 


Part 2: Habitat Chapters

No Name Revision

Coastlands (coastal saltmarsh, sand dune, machair, shingle, and maritime cliff and slopes, habitats)

Revised (2019)
1b Marine Intertidal & Shallow Subtidal Revised (2019)
1c Saline lagoons  Revised (2022)
2 Woodlands Revised (2018)
3 Lowland grasslands  Revised (2014)
4 Lowland heathland Revised (2018)
5 Non-montane rock habitats (1989) Revision underway
6 Freshwater habitats Revised (2018)
7 Fens (1989) Revision underway
8 Bogs (1994) Revision underway
9 Upland habitats (1989) Revision underway
10 Artificial habitats (1989) Revision underway


Part 2: Species Chapters

No. Name Revision
11 Vascular plants Revised (2021)


Revised (2018)

Lichens and associated microfungi

Revised (2018)
14 Fungi (non-lichenised) Revised (2018)
15 Charophytes (stoneworts) Revised (2020)
16 Mammals Revised (2019)
17 Birds  Revised (2015; updated 2020)
18 Reptiles and amphibians  Revised (2022)
19 Freshwater fish Revised (2018)
19b Estuarine fish Revised (2022)
20 Invertebrates  Revised (2019)

Please cite as: JNCC, Guidelines for selection of biological SSSIs


Published: .

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