Isadora E. Fluck

Conflicts of Interest The authors declare no conflicts of interest. Data Availability Statement All data and code for this study will be made publicly available on Figshare upon publication at https://figshare.com/s/6570f4490d656a0d4850. Supporting Information Filename Description geb70266-sup-0001-TableS1-S9-FigureS1-S4.pdfPDF document, 1.1 MB Supporting Information S1.

1 INTRODUCTION A central focus of ecology is to understand how species relate to their biotic and abiotic environments. Species traits have long been used as a currency for linking species to environmental gradients (de Bello et al., 2021; McGill et al., 2006) and assessing the influence of biotic interactions on biodiversity patterns (Read, Baiser, et al., 2018; Whittaker, 1972).

Introduction Species composition can be affected by several factors such as geographic barriers, climatic factors and geographic distance, creating different spatial patterns of species distribution (Qian and Ricklefs 2012). Although the effects of rivers, climate and geographic distance on species distribution have been extensively explored for several taxa (Buckley and Jetz 2008, Naka and Brumfield 2018), the relative importance of these processes is not well understood.