Distance decay 2.0 – a global synthesis of taxonomic and functional turnover in ecological communities
Authors: Graco-Roza Caio , Aarnio Sonja , Abrego Nerea , Acosta Alicia T. R. , Alahuhta Janne , Altman Jan , Angiolini Claudia , Aroviita Jukka , Attorre Fabio , Baastrup-Spohr Lars , Barrera-Alba José Juan , Belmaker Jonathan , Biurrun Idoia , Bonari Gianmaria , Bruelheide Helge , Burrascano Sabina , Carboni Marta , Cardoso Pedro , Carvalho José Carlos , Castaldelli Giuseppe , Christensen Morten , Correa Gilsineia , Dembicz Iwona , Dengler Jürgen , Dolezal Jiri , Domingos Patricia , Erös Tibor , Ferreira Carlos E. L. , Filibeck Goffredo , Floeter Sergio R. , Friedlander Alan , Gammal Johanna , Gavioli Anna , Gossner Martin M. , Granot Itai , Guarino Riccardo , Gustafsson Camilla , Hayden Brian , He Siwen , Heilmann-Clausen Jacob , Heino Jani , Hunter John T. , Huszar Vera Lucia de Moraes , Janišová Monika , Jyrkänkallio-Mikkola Jenny , Kahilainen Kimmo , Kemppinen Julia , Kozub Łukasz , Kruk Carla , Kulbiki Michel , Kuzemko Anna , Roux Peter Christian le , Lehikoinen Aleksi , Lima Domênica Teixeira de , Lopes-Urrutia Angel , Lukács Balázs A. , Luoto Miska , Mammola Stefano , Marinho Marcelo Manzi , Menezes Luciana da Silva , Milardi Marco , Miranda Marcela , Moser Gleyci Aparecida Oliveira , Mueller Joerg , Niittynen Pekka , Norkko Alf , Nowak Arkadiusz , Ometto Jean , Ovaskainen Otso , Overbeck Gerhard E. , Pacheco Felipe Siqueira , Pajunen Virpi , Palpurina Salza , Picazo Félix , Prieto Juan Antonio Campos , Rodil Ivan F. , Sabatini Francesco Maria , Salingré Shira , Sanctis Michele de , Segura Angel M. , da Silva Lucia Helena Sampaio , Stevanovic Zora Dajic , Swacha Grzegorz , Teittinen Anette , Tolonen Kimmo T. , Tsiripidis Ioannis , Virta Leena , Wang Beixin , Wang Jianjun , Weisser Wolfgang , Xu Yuan , Soininen Janne 
Published: March 2021

Understanding the variation in community composition and species abundances, i.e., β-diversity, is at the heart of community ecology. A common approach to examine β-diversity is to evaluate directional turnover in community composition by measuring the decay in the similarity among pairs of communities along spatial or environmental distances. We provide the first global synthesis of taxonomic and functional distance decay along spatial and environmental distance by analysing 149 datasets comprising different types of organisms and environments. We modelled an exponential distance decay for each dataset using generalized linear models and extracted r2and slope to analyse the strength and the rate of the decay. We studied whether taxonomic or functional similarity has stronger decay across the spatial and environmental distances. We also unveiled the factors driving the rate of decay across the datasets, including latitude, spatial extent, realm, and organismal features. Taxonomic distance decay was stronger along spatial and environmental distances compared with functional distance decay. The rate of taxonomic spatial distance decay was the fastest in the datasets from mid-latitudes while the rate of functional decay increased with latitude. Overall, datasets covering larger spatial extents showed a lower rate of decay along spatial distances but a higher rate of decay along environmental distances. Marine ecosystems had the slowest rate of decay. This synthesis is an important step towards a more holistic understanding of patterns and drivers of taxonomic and functional β-diversity.