The identification and distribution of Sphagnum balticum (Russow) C.E.O.Jensen in Britain

ABSTRACT

Introduction

The aims of this study were to help clarify the identification of Sphagnum balticum in Britain, to review its distribution, and to investigate the possible presence of hybrids between it and either S. cuspidatum or S. fallax.

Methods

All sites at which Sphagnum balticum has been recorded recently in Britain were visited in 2020, and a search made for it and other species with which it could be confused, together with possible hybrids. Samples were collected when suitable material was found. DNA was extracted from 31 shoots, each representing one field sample. Fifteen microsatellites that have been developed for Sphagnum species were amplified and genotyped. The genetic structure of the data was investigated using principal coordinate analysis and cluster analysis.

Results

The results of the genetic analysis support the recognition of four taxa, which corresponded to four morphologically identified taxa: Sphagnum angustifolium, S. balticum, S. cuspidatum and S. fallax. There was no evidence of hybrids. Over-recording of S. balticum has occurred in Britain due to confusion with some forms of S. cuspidatum and S. fallax, which can exhibit some morphological characters usually used to identify S. balticum. An illustrated identification key is provided to help solve this problem.

Conclusions

Sphagnum balticum is a very rare species in Britain that has undergone a decline due to habitat destruction and alteration. It is presently known to survive at only three sites, of which two are within protected areas.

KEYWORDS:

• Microsatellites
• Sphagnum cuspidatum
• Sphagnum fallax

Acknowledgements

Many thanks to Martin Furness (Natural England) for managing the project contract. For various help and support, many thanks to Tom Blockeel (Sheffield, UK), Sam Bosanquet (Natural Resources Wales), Dave Genney (NatureScot), Steven Heathcote (JBA Consulting), Niklas Lönnell (Swedish University of Agricultural Sciences), John O’Reilly (Ptyxis Ecology), Dave Reed (Natural Resources Wales), Chris Tilbury (Royal Society for the Protection of Birds) and Rachel Webster (MANCH). Thanks also to NINA Genlab for assistance in the laboratory, and to reviewers for reviewing the manuscript.

Disclosure statement

No potential conflicts of interest were reported by the authors.

Additional information

Funding

Funding for this study was provided by Natural England and the British Bryological Society.

Notes on contributors

Des A. Callaghan

Des A. Callaghan is a consultant bryologist operating under Bryophyte Surveys Ltd, working throughout Britain and further afield. His research is focused on threatened species, taxonomy and conservation ecology.

Magni Olsen Kyrkjeeide

Magni O. Kyrkjeeide is a researcher at Norwegian Institute for Nature Research (NINA), Trondheim, Norway, working on Sphagnum systematics, mire restoration, monitoring and conservation of threatened species.

Kristian Hassel

Kristian Hassel is a professor at Norwegian University of Science and Technology, Trondheim, Norway, where he is head of the botanical collections at NTNU University Museum. His research focuses on bryophyte biosystematics with a special emphasis on speciation processes and biogeography of northern species, but also including questions related to applied conservation biology.