Storm effects on intertidal invertebrates: increased beta diversity of few individuals and species

Abstract

Climate change is predicted to lead to more extreme weather events, including changes to storm frequency, intensity and location. Yet the ecological responses to storms are incompletely understood for sandy shorelines, the globe’s longest land-ocean interface. Here we document how storms of different magnitude impacted the invertebrate assemblages on a tidal flat in Brazil. We specifically tested the relationships between wave energy and spatial heterogeneity, both for habitat properties (habitat heterogeneity) and fauna (β-diversity), predicting that larger storms redistribute sediments and hence lead to spatially less variable faunal assemblages. The sediment matrix tended to become less heterogeneous across the flat after high-energy wave events, whereas β-diversity increased after storms. This higher β-diversity was primarily driven by species losses. Significantly fewer species at a significantly lower density occurred within days to weeks after storms. Negative density and biomass responses to storm events were most prominent in crustaceans. Invertebrate assemblages appeared to recover within a short time (weeks to months) after storms, highlighting that most species typical of sedimentary shorelines are, to some degree, resilient to short-term changes in wave energy. Given that storm frequency and intensity are predicted to change in the coming decades, identifying properties that determine resilience and recovery of ecosystems constitute a research priority for sedimentary shorelines and beyond.

Spatial and temporal variation in the diet of the sandy beach gastropod Olivella minuta

“…Amaral et al () investigated the intertidal macrofauna of both beaches and found that the number of species and abundance of individuals in Araçá Bay was more than double that observed at Barequeçaba. Similarly, Corte, Checon, et al (), Corte, Schlacher, et al () registered hundreds of macrofaunal species at Araçá, including higher numbers of polychaetes, molluscs, and crustaceans, whereas Nucci et al () registered only three species of Crustacea at Barequeçaba. The larger abundance of feeding items at Araçá, and more selective and constant feeding behavior by individuals of O. minuta at this site, may also explain the very high production and turnover (production/biomass) ratio observed by Petracco et al (), which is one of the highest found so far for sandy beach gastropods.…”

Effects of a tropical cyclone on salt marsh insect communities and post‐cyclone reassembly processes

“…surveys between pre‐Isaac and the third day after it landed, between the third and 14th day after the hurricane, and so on). We used a Bray–Curtis distance measure to calculate a dissimilarity index for each site (Corte et al , Vokurkova et al ), and ternary plots to visualize the relative contribution of the three components of β diversity to overall differences between consecutive time periods. In the ternary plots, values of replacement, abundance difference, and similarity decide the position of each dot (representing the difference in community structure measured between consecutive time periods) in the plot.…”

Do natural disturbances have significant effects on sandy beach macrofauna of Southeastern Brazil?

“…Although storms are expected to enhance erosive processes and directly kill macroinvertebrates (Mclachlan et al 1996), studies have suggested that several macrofaunal species, mainly detritivorous ones, as the crustacean E. braziliensis, are resilient to moderate events on non-urbanized sandy beaches, regardless of morphodynamics (Alves and Pezzuto 2009, Harris et al 2011, Machado et al 2016. As suggested by other authors (Machado et al 2016, Corte et al 2017, storm wave events may enhance both redistribution of sediment fauna and productivity at sandy shores, reducing competition and increasing macrofauna richness, density and diversity. Moderate storms may increase short-term deposition of organic detritus (e.g.…”

“…However, dissipative and undisturbed beach populations may also be controlled by ecological interactions (e.g., density-dependent mechanisms) (Defeo and Mclachlan 2005). Other environmental conditions are thought to be important drivers of the community structure of the macrofauna, including temperature (Taylor and Mclachlan 1980), food availability (Bergamino et al 2013), and natural disturbances such as storms (Harris et al 2011, Machado et al 2016, Corte et al 2017 and rainfall Defeo 1999, 2015).…”