The microclimate occupied by the hyperoceanic liverwort Leptoscyphus cuneifolius (Hook.) Mitt. within a temperate rain forest in Wales

ABSTRACT

Introduction

Because climate change risks serious negative impacts on drought-sensitive species in Britain, in the short as well as the long term, the microclimate occupied by the hyperoceanic liverwort Leptoscyphus cuneifolius within a temperate rain forest in Wales was investigated.

Methods

At Coed y Rhygen, Gwynedd, Wales, 10 trees occupied by the liverwort were randomly selected, and its abundance was measured on the southerly and northerly aspect of each trunk. Data loggers were installed to measure temperature, relative humidity and illuminance on both aspects, from 1 January 2020 to 31 December 2022. Temperature and relative humidity values were used to calculate vapour pressure deficit (VPD). Bootstrap paired t-tests were used to test for significant differences in the mean number of locations of Leptoscythus cuneifolius on the southerly versus northerly aspects of trunks, and in the monthly mean values of temperature, VPD and illuminance on the southerly versus northerly aspects.

Results and conclusions

Leptoscyphus cuneifolius is significantly more abundant on the northerly aspect of trunks, and the microclimate that it occupies is dynamic, both spatially and temporally. In early spring, a sharp peak occurs in solar radiation and VPD, especially on the southerly aspect, caused by the altitude of the sun rising from its winter low and the subsequent emergence of the deciduous forest leaf canopy. Further study is required to understand the effects of the macroclimate on the microclimate occupied by hyperoceanic bryophytes in temperate rain forest, and to what extent this habitat may provide a refuge from climate change.

KEYWORDS:

• Bryophyte
• climate change
• oceanic woodland
• vapour pressure deficit

Acknowledgement

Many thanks to Graham Williams (Natural Resources Wales) for overseeing the contract for this work.

Disclosure statement

No potential conflict of interest was reported by the author.

Additional information

Funding

Funding for this work was provided by Natural Resources Wales.

Notes on contributors

Des A. Callaghan

Des Callaghan is a consultant bryologist operating under Bryophyte Surveys Ltd. His research is focused on threatened species, conservation ecology and taxonomy.