Species turnover drives β-diversity patterns across multiple spatial and temporal scales in Great Lake Coastal Wetland Communities

β dissimilarity indices have described community variation occurring from unique structuring processes: species turnover and nestedness. However, the importance of scale definition remains critical and challenging during β assessments with a need for simultaneous spatial and temporal assessment to determine ecological phenomena governing biological communities. We aim to examine the contribution of turnover and nestedness structuring processes across multiple spatial and temporal scales to demonstrate the importance of scale consideration in β assessments. Using a site-to-basin-wide spatiotemporal hierarchical design, we examined diversity patterns, testing spatial, and temporal facets of β diversity structuring Laurentian Great Lake coastal wetland fish and macroinvertebrate communities from 2000 to 2012. Both fish and macroinvertebrate communities were analyzed using β dissimilarity indices under the same hierarchical design. Results indicated strong spatial and temporal turnover structuring with increasing β diversity and community turnover as scale localized. We suggest that high turnover is the result of inhospitable winter conditions followed by random re-colonization events in the spring. With relatively unique communities across space and time, biodiversity-oriented management of coastal wetlands should consider an all-inclusive approach as biodiversity hotspots are not apparent.