Modelling the future distribution of rare bryophytes in Scotland: the importance of the inclusion of habitat loss

ABSTRACTBackground Species distribution models (SDMs) have been widely used to predict species ranges and their future distribution under climate change scenarios, mostly using only climatic variables. An important factor that is usually neglected, is the habitat of the species that are being modelled. Even when included, it is often considered a fixed factor, but in reality, it is also subjected to changes.Aims In this study, we assessed if this omission can lead to different projected distributions of the species.Methods For this purpose, we applied an ensemble of SDMs, and we projected the distribution of rare bryophyte species in Scotland in the 2050s. Bryophytes are generally very climate-reliant and lend themselves to bioclimatic studies, and we selected species different grades of affinity with blanket bogs, which are threatened by climate change. Blanket bog extension was included in the model as an explanatory variable, and the models were run for three 2050s scenarios: once with the current blanket bog distribution and twice using the blanket bog distribution derived from two bioclimatic models (Lindsay modified and Blanket Bog Tree model), under the same climate change projections.Results The results showed some differences in the predicted future distribution of those species with a strong relationship with blanket bogs, when habitat changes were accounted for. For example, Sphagnum majus, the species with the highest affinity with blanket bog in our study, was not predicted to change its future distribution when blanket bog is held constant at the current level, but was predicted to lose up to 60% of its current suitable area when the projected loss of blanket bog is included.Conclusion Our results suggest that adding future habitat changes could improve the reliability of SDMs in the first steps of planning for conservation and restoration.KEYWORDS: Blanket bogbryophytesclimate changespecies distribution modelsensembleDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. AcknowledgementsWe thank Andrew Coupar for his help in defining the list of bryophyte species for the study, Astley Hastings and the ADVENT project for providing the Land Cover Map and Christopher Ellis for his technical advice with Maxent. We also thank the many anonymous reviewers who have contributed to greatly improving the manuscript from its first version to this final one. This work was supported by a Studentship from the Macaulay Development Trust (Grant Number: E000646-507 00).Declaration of InterestsThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.Supplementary materialSupplemental data for this article can be accessed online at https://doi.org/10.1080/17550874.2023.2274839Additional informationFundingThe work was supported by the Macaulay Development Trust [E000646-507 00].Notes on contributorsAnna FerrettoAnna Ferretto conceptualisation, methodology and writing – review and editing- formal analysis, writing, original draft preparation; Pete Smith: conceptualisation, methodology and writing – review and editing, supervision; David Genney: methodology and writing – review and editing; Robin Matthews: conceptualisation, methodology and writing, review and editing, supervision. Mostafa Hadizadeh: methodology and climate data bias correction; Rob Brooker: conceptualisation, methodology and writing, review and editing, supervision.Anna Ferretto is interested in the effects of climate change on different ecosystem services and biodiversity and in the concept of planetary boundaries and how our societies can thrive within these biophysical limits.Pete SmithPete Smith is interested in climate change impacts on ecosystems, and land management for climate change mitigation, adaptation and to enhance nature.David Robert GenneyDavid Robert Genney is a plant ecologist, specialised in bryophytes, lichens and fungi, and interested in the development of monitoring techniques for each of these species groups.Robin MatthewsRobin Matthews research interests are in the processes of change and adaptation in coupled socio-ecological systems in response to external drivers, and in using integrated modelling approaches to explore mitigation and adaptation to climate change, and to the provision of ecosystem services.Mostafa HadizadehMostafa Hadizadeh is interested in the intersection of data science and environmental science, with a specific emphasis on developing innovative data-driven approaches to tackle urgent environmental challenges.Rob BrookerRob Brooker is a plant ecologist interested in how environmental drivers such as land use and climate change impact on the composition of plant communities and how they function.