Ulrike Herzschuh, Kathleen R. Stoof-Leichsenring, Luca Zsofia Farkas, Ying Liu, Sisi Liu, Thomas Böhmer, Izabella Baisheva, Boris K. Biskaborn, Jérémy Courtin, Bernhard Diekmann, Laura S. Epp, Barbara von Hippel, Sichao Huang, Yongson Huang, Weihan Jia, Darrell S. Kaufman, Hanno Meyer, Martin Melles, Stefano Meucci, Luidmila A. Pestryakova, Luise Schulte, Bernd Wagner, Zhigang Wang, Evgenii S. Zakharov
- Ecological connectivity shapes ecosystem responses to climate change and is thought to underpin stability, yet its millennial-scale dynamics remain poorly resolved. We asked how spatial and temporal connectivity of plant metacommunities changed over the last 40 ka and which processes drove it. We analysed and compiled plant sedimentary DNA from 20 lake cores across Beringia (Siberia, Alaska) to investigate community dynamics and, for a high-resolution subset, applied beta- and zeta-diversity to track connectivity. Vegetation changed coherently across the glacial–Holocene transition, with trait shifts mirroring functional composition. Connectivity peaked during the late MIS3 and Last Glacial Maximum—likely aided by the Bering Land Bridge, mass effects and facilitation—collapsed during the Deglacial with rapid turnover, and rebounded in the Holocene as shrub and boreal communities expanded. Temporal zeta within sites exceeded spatial zeta, indicating strong local persistence andEcological connectivity shapes ecosystem responses to climate change and is thought to underpin stability, yet its millennial-scale dynamics remain poorly resolved. We asked how spatial and temporal connectivity of plant metacommunities changed over the last 40 ka and which processes drove it. We analysed and compiled plant sedimentary DNA from 20 lake cores across Beringia (Siberia, Alaska) to investigate community dynamics and, for a high-resolution subset, applied beta- and zeta-diversity to track connectivity. Vegetation changed coherently across the glacial–Holocene transition, with trait shifts mirroring functional composition. Connectivity peaked during the late MIS3 and Last Glacial Maximum—likely aided by the Bering Land Bridge, mass effects and facilitation—collapsed during the Deglacial with rapid turnover, and rebounded in the Holocene as shrub and boreal communities expanded. Temporal zeta within sites exceeded spatial zeta, indicating strong local persistence and resilience. Tundra sites uninvaded by forest maintained continuous species pools. Overall, these patterns underscore the value of a metacommunity perspective for assessing millennial-scale connectivity changes.…
