Improving forecasts of arctic-alpine refugia persistence with landscape-scale variables

ABSTRACT

Refugia, the sites preserving conditions reminiscent of suitable climates, are projected to be crucial for species in a changing climate, particularly at high latitudes. However, the knowledge of current locations of high-latitude refugia and particularly their ability to retain suitable conditions under future climatic changes is limited. Occurrences of refugia have previously been mainly assessed and modelled based solely on climatic features, with insufficient attention being paid to potentially important landscape-scale factors. Here, climate-only models and ‘full’ models incorporating topo-edaphic landscape-scale variables (radiation, soil moisture and calcareousness) were developed and compared for 111 arctic-alpine plant species in Northern Fennoscandia. This was done for both current and future climates to determine cells with resilient climatic suitability harbouring refugia. Our results show that topographic and edaphic landscape-scale predictors both significantly improve models of arctic-alpine species distributions and alter projections of refugia occurrence. The predictions of species–climate models ignore landscape-scale ecological processes and may thus provide inaccurate estimates of extinction risk and forecasts of refugia where species can persist under a changing climate.

KEYWORDS:

• Climate change
• refugia
• landscape-scale factor

Acknowledgement

We would like to thank the Finnish Museum of Natural History as one of the main contributors of the data on vascular plant species and Juha Aalto for helping with gathering the environmental data and data analysis.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Annina K.J. Niskanen is a doctoral researcher at the Department of Geosciences and Geography, University of Helsinki, and is interested in the functioning of plant refugia and modelling vulnerable ecosystems.

Dr Risto K. Heikkinen is a senior research scientist at The Finnish Environment Institute with expertise on conservation biology of threatened ecosystems and modelling the climate change impacts on biodiversity.

Dr Heidi K. Mod is a postdoc at the University of Lausanne and is interested in biotic interactions among cold-adapted vegetation.

Dr Henry Väre is a senior curator and Principal Investigator at The Finnish Museum of Natural History.

Miska Luoto is a professor at the Department of Geosciences and Geography, University of Helsinki. His study interests are related to the integration of remote sensing and geographical information data in global change modelling.

Additional information

Funding

AN was funded by the Lapland Regional Fund (Finnish Cultural Foundation), Societas pro Fauna et Flora Fennica and The Doctoral Program in Geosciences. We acknowledge funding from the Academy of Finland (Project Number 1140873). Also, HM was partly founded by the Alfred Kordelin Foundation and The Doctoral Program in Geosciences, and ML was partly funded by the Academy of Finland (Project Number 286950).