Introduction

Red lists and lists of nationally rare and scarce plants are commonly used conservation tools, used to focus conservation effort and influence policy and decision making.

For some years, the BBS has periodically produced lists of nationally rare and scarce bryophytes. Nationally rare taxa in Britain (excluding Ireland) are defined as those occurring in 1–15 10 km squares, whilst nationally scarce taxa occur in 16–100 10 km squares. It can be interesting to compare lists to identify those species which are declining – and conversely, those which are increasing. The most recent lists have been published in Field Bryology, and links are given below.

In 2013, Nick Hodgetts and Neil Lockhart produced an equivalent list for Ireland, although using slightly different criteria to identify rarity. Their article also clearly explains the distinction between these lists and the more rigorous Red Lists, and clarifies the purpose of each. Both authors were also involved in the production of the first Red List for bryophytes in Ireland (see next section).

Red Lists categorise species according to their risk of extinction, taking into account factors like population decline, range contraction, habitat loss etc. in addition to rarity. In 1964, the International Union for Conservation of Nature (IUCN) was founded, and this organisation is responsible for compiling and publishing the IUCN Red List of Threatened Species – the world’s most comprehensive inventory of the global conservation status of biological species. The IUCN not only endeavours to assess the threats to all species, but to repeat the assessment every few years to give a picture of whether a species is stable, declining or increasing over time. In practical terms however, it is not possible to assess every single species and there is still a place for other organisations to produce regional Red Lists of certain species groups.

The first Red List for Britain was produced in 2001; the list was updated on an ad hoc basis, until in 2011 Nick Hodgetts published a new Revised Red List of bryophytes in Britain. More recently, Des Callaghan has produced a Red List of the Bryophytes of Britain which follows IUCN guidance and includes distribution data from the 2014 Atlas (somewhat confusingly, this paper was published in 2023, in the last issue of Journal of Bryology 44, (2022)).

These Red Lists cover England, Scotland, Wales and the Isle of Man, but exclude Ireland, Northern Ireland and the Channel Islands.

BBS members have also produced Red Lists for bryophytes in both Ireland and Wales, and a European Red List was published in 2019.