Global Arthropod beta-diversity is spatially and temporally structured by latitude
Authors: Seymour Mathew , Roslin Tomas , deWaard Jeremy , Perez Kate , D'Souza Michelle , Ratnasingham Sujeevan , Ashfaq Muhammad , Levesque-Beaudin Valerie , Blagoev Gergin , Bukowski Belén , Cale Peter , Crosbie Denise , Decaëns Thibaud , deWaard Stephanie , Ekrem Torbjørn , Elansary Hosam , Ondo Fidèle Evouna , Fraser David , Geiger Matthias , Hajibabaei Mehrdad , Hallwachs Winnie , Hanisch Priscila , Hausmann Axel , Heath Mark , Hogg Ian , Janzen D , Kinnaird Margaret , Kohn Joshua , Larrivée Maxim , Lees David , León-Règagnon Virginia , Liddell Michael , Lijtmaer Darío , Lipinskaya Tatsiana , Locke Sean , Manjunath Ramya , Martins Dino , Martins Marlúcia , Mazumdar Santosh , McKeown Jaclyn , Miller Scott , Milton Megan , Miskie Renee , Morinière Jérôme , Mutanen Marko , Naik Suresh , Nichols Becky , Noguera Felipe , Novotny Vojtech , Penev Lyubomir , Pentinsaari Mikko , Quinn Jenna , Ramsay Leah , Rochefort Regina , Schmidt Stefan , Smith M. , Sobel Crystal , Somervuo Panu , Sones Jayme , Staude Hermann , Jaques Brianne St. , Stur Elisabeth , Telfer Angela , Tubaro Pablo , Wardlaw Timothy , Worcester Robyn , Yang Zhaofu , Young Monica R. , Zemlak Tyler , Zakharov Evgeny , Zlotnick Bradley , Ovaskainen Otso , Hebert Paul 
Published: September 2023

Aim: Global gradients in species biodiversity may or may not be associated with greater species replacement closer to the equator. Yet, empirical validation of these patterns has so far focused on less diverse taxa, with comparable assessments of mega-diverse groups historically constrained by the taxonomic impediment.
Location: Global
Time period: 2010-2017
Major taxa studied: Terrestrial arthropods
Methods: Here we assess the temporal and spatial dynamics of arthropod communities using a beta-diversity framework, drawing on samples across 129 globally distributed monitoring sites. Overall, we encountered more than 150,000 unique barcode index numbers (BINs) (i.e. species proxies). We assessed between site differences in community diversity using beta-diversity and the partitioned beta-diversity components of species replacement (i.e. turnover) and richness difference (i.e. a measure of nestedness).
Results: We show that global differences in community compositional change are linked to latitudinal, spatial, and temporal gradients. General global beta-diversity trends remained consistent across biogeographic regions, with beta-diversity (dissimilarity) increasing with decreasing latitude, greater spatial distance and greater temporal distance. By contrast, species replacement and richness difference patterns varied across biogeographic regions, suggesting different underlying processes are shaping regional biodiversity patterns. Latitudinal effects on species replacement or richness difference were significant for 3 out of 5 regions. Comparably we found significant spatial distance relationships with species replacement or richness difference for 3 out of 5 regions. Temporal distance was significantly associated with species replacement or richness difference for all 5 regions.
Main conclusion: The general expectations of the latitudinal diversity gradient (LDG) are supported using a large, extensive global sampling effort. Our findings generally support the global LDG expectations, however, partitioned assessment of beta-diversity indicates the underlying processes driving the general global pattern, here species replacement and richness difference, may be regionally linked to differences in seasonality effects or variation in spatial distribution of environmental factors.