Northward shift of a biogeographical barrier on China's coast.

Aim: Understanding the formation and maintenance of biogeographical breaks is fundamental for developing analyses related to biodiversity and conservation. Biogeographical patterns along China's coast are changing dramatically in the face of climate change and alterations in land‐use. In this paper, we sought to clarify the mechanisms responsible for the formation and maintenance of a biogeographical barrier on China's coast. Location: Coastline of northern China. Methods: We have reviewed literature of research related to biogeographical and phylogeographical patterns of intertidal macrobenthos along the coast of Jiangsu Province and adjacent areas, summarized the distribution patterns and biogeographical breakers. We have also reviewed literature about the processes and drivers on coastal biogeographical breaks, to clarify the mechanisms acting to the northward shift of the biogeographical break. Results: The Yangtze (Changjiang) River Estuary Biogeographical Barrier (YREBB) at 30°–31°N, which serves as a coastal biogeographical boundary for the Cold Temperate Northwest Pacific Province and the Warm Temperate Northwest Pacific Province for marine species, has moved northward to ~33°–34°N due to the changes in habitat continuity, oceanographic circulation and climate factors. Consequently, a new biogeographic barrier for intertidal macrobenthos, the Subei Biogeographical Barrier (SBB) on the central coast of Jiangsu Province, has emerged. Main conclusions: The formation and maintenance of the SBB are closely related to the larval dispersal potential, larval settlement success and post‐settlement population establishment, all of which have been profoundly influenced by anthropogenic environmental changes. The northward shift of the YREBB and the appearance of the SBB provide an excellent model system for investigating the impacts of climate change and land‐use change on coastal biogeographic patterning and for clarifying the mechanisms underlying the formation and maintenance of biogeographical barriers in the face of the unprecedented environmental changes. [ABSTRACT FROM AUTHOR]