Understanding the local drivers of beta‐diversity patterns under climate change: The case of seaweed communities in Galicia, North West of the Iberian Peninsula

Aim To understand spatial-temporal changes (beta-diversity) in coastal communities and their drivers the context of climate change. Coastal ecosystems are extremely exposed dynamic, where seaweed assemblages have been associated with changing water temperatures. However, at local scale, effects upwelling events related stressors seek further exploration. Location Galicia rías, North West Iberian Peninsula. Methods Using data collected 42 sampling localities rias over two time periods (1998 2014), we analysed community's composition through space. We calculated temporal beta-diversity index spatial as pairwise differences between localities. use generalized dissimilarity models, to identify environmental beta-diversity. Results found a significant change rias, 1998 2014 (temporal beta-diversity). They were mostly species loss rather than replacement. The among (spatial beta-diversity) was significantly higher 1998. Nitrate concentration consistently predicted main driver both patterns. Main conclusions Unlike other studies marine ecosystems, our results suggest that observed structure perennial Rias might lead biotic heterogenization, indirectly linked nutrients availability intensity. Changes call scientific attention importance studies.