Thermal homogenization of boreal communities in response to climate warming
Abstract
Globally, rising temperatures are increasingly favoring warm-affiliated species. Although changes in community composition are typically measured by the mean temperature affinity of species (the community temperature index, CTI), they may be driven by different processes and accompanied by shifts in the diversity of temperature affinities and breadth of species thermal niches. To resolve the pathways to community warming in Finnish flora and fauna, we examined multidecadal changes in the dominance and diversity of temperature affinities among understory forest plant, freshwater phytoplankton, butterfly, moth, and bird communities. CTI increased for all animal communities, with no change observed for plants or phytoplankton. In addition, the diversity of temperature affinities declined for all groups except butterflies, and this loss was more pronounced for the fastest-warming communities. These changes were driven in animals mainly by a decrease in cold-affiliated species and an increase in warm-affiliated species. In plants and phytoplankton the decline of thermal diversity was driven by declines of both cold- and warm-affiliated species. Plant and moth communities were increasingly dominated by thermal specialist species, and birds by thermal generalists. In general, climate warming outpaced changes in both the mean and diversity of temperature affinities of communities. Our results highlight the complex dynamics underpinning the thermal reorganization of communities across a large spatiotemporal gradient, revealing that extinctions of cold-affiliated species and colonization by warm-affiliated species lag behind changes in ambient temperature, while communities become less thermally diverse. Such changes can have important implications for community structure and ecosystem functioning under accelerating rates of climate change.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (35)
Jussi Mäkinen
Research Center for Ecological Change, Organismal and Evolutionary Research Programme, Faculty of Biological and Environmental Sciences
Emilie E. Ellis
Research Center for Ecological Change, Organismal and Evolutionary Research Programme, Faculty of Biological and Environmental Sciences
Laura H. Antão
Andréa Davrinche
Research Center for Ecological Change, Organismal and Evolutionary Research Programme, Faculty of Biological and Environmental Sciences
Anna-Liisa Laine
Research Center for Ecological Change, Organismal and Evolutionary Research Programme, Faculty of Biological and Environmental Sciences
Marjo Saastamoinen
Research Center for Ecological Change, Organismal and Evolutionary Research Programme, Faculty of Biological and Environmental Sciences
Irene Conenna
Research Center for Ecological Change, Organismal and Evolutionary Research Programme, Faculty of Biological and Environmental Sciences
Maria Hällfors
Research Center for Ecological Change, Organismal and Evolutionary Research Programme, Faculty of Biological and Environmental Sciences
Andrea Santangeli
Research Center for Ecological Change, Organismal and Evolutionary Research Programme, Faculty of Biological and Environmental Sciences
Elina Kaarlejärvi
Janne Heliölä
Nature Solutions Unit
Ida-Maria Huikkonen
Nature Solutions Unit
Mikko Kuussaari
Nature Solutions Unit
Reima Leinonen
Kainuu Centre for Economic Development, Transport and the Environment
Aleksi Lehikoinen
Finnish Museum of Natural History
Juha Pöyry
Nature Solutions Unit
Anna Suuronen
Nature Solutions Unit
Maija Salemaa
Natural Resources Institute Finland
Tiina Tonteri
Natural Resources Institute Finland
Kristiina M. Vuorio
Nature Solutions Unit
Birger Skjelbred
Norwegian Institute for Water Research
Marko Järvinen
Nature Solutions Unit
Stina Drakare
Department of Aquatic Sciences and Assessment
Laurence Carvalho
Norwegian Institute for Water Research
Erik Welk
Department of Geobotany and Botanical Garden, Martin Luther University
Gunnar Seidler
Department of Geobotany and Botanical Garden, Martin Luther University
Pieter Vangansbeke
František Máliš
Radim Hédl
Alistair G. Auffret
Department of Ecology
Jan Plue
Pieter De Frenne
Jesse M. Kalwij
Institute of Geography and Geoecology
Jarno Vanhatalo
Research Center for Ecological Change, Organismal and Evolutionary Research Programme, Faculty of Biological and Environmental Sciences
Tomas Roslin
Department of Ecology