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 J. , Belmaker Jonathan , Biurrun Idoia , Bonari Gianmaria , Bruelheide Helge , Burrascano Sabina , Carboni Marta , Cardoso Pedro , Carvalho José C. , 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 M. , 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 L. M. , Janišová Monika , Jyrkänkallio‐Mikkola Jenny , Kahilainen Kimmo K. , Kemppinen Julia , Kozub Łukasz , Kruk Carla , Kulbiki Michel , Kuzemko Anna , Christiaan le Roux Peter , Lehikoinen Aleksi , Teixeira de Lima Domênica , Lopez‐Urrutia Angel , Lukács Balázs A. , Luoto Miska , Mammola Stefano , Marinho Marcelo M. , Menezes Luciana S. , Milardi Marco , Miranda Marcela , Moser Gleyci A. O. , Mueller Joerg , Niittynen Pekka , Norkko Alf , Nowak Arkadiusz , Ometto Jean P. , Ovaskainen Otso , Overbeck Gerhard E. , Pacheco Felipe S. , Pajunen Virpi , Palpurina Salza , Picazo Félix , Campos Juan Antonio , Rodil Iván F. , Sabatini Francesco M. , Salingré Shira , De Sanctis Michele , Segura Angel M. , da Silva Lucia H. S. , Stevanovic Zora D. , Swacha Grzegorz , Teittinen Anette , Tolonen Kimmo T. , Tsiripidis Ioannis , Virta Leena , Wang Beixin , Wang Jianjun , Weisser Wolfgang , Xu Yuan , Soininen Janne 
Published: May 2022

Aim

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 variation in community composition by measuring the decay in the similarity among pairs of communities along spatial or environmental distance. We provide the first global synthesis of taxonomic and functional distance decay along spatial and environmental distance by analysing 148 datasets comprising different types of organisms and environments.

Location

Global.

Time period

1990 to present.

Major taxa studied

From diatoms to mammals.

Method

We measured the strength of the decay using ranked Mantel tests (Mantel r) and the rate of distance decay as the slope of an exponential fit using generalized linear models. We used null models to test whether functional similarity decays faster or slower than expected given the taxonomic decay along the spatial and environmental distance. We also unveiled the factors driving the rate of decay across the datasets, including latitude, spatial extent, realm and organismal features.

Results

Taxonomic distance decay was stronger than functional distance decay along both spatial and environmental distance. Functional distance decay was random given the taxonomic distance decay. The rate of taxonomic and functional spatial distance decay was fastest in the datasets from mid‐latitudes. Overall, datasets covering larger spatial extents showed a lower rate of decay along spatial distance but a higher rate of decay along environmental distance. Marine ecosystems had the slowest rate of decay along environmental distances.

Main conclusions

In general, taxonomic distance decay is a useful tool for biogeographical research because it reflects dispersal‐related factors in addition to species responses to climatic and environmental variables. Moreover, functional distance decay might be a cost‐effective option for investigating community changes in heterogeneous environments.