Different functional feeding groups of mangrove soil molluscs invoke unique co‐occurrence patterns in response to a climate extreme

Abstract

AbstractAimDue to differences in community functional traits and composition, the response of communities to environmental changes can be variable, and thus an understanding of the mechanisms underlying differential functional group responses is necessary. We investigated a mangrove soil mollusc community before (in 2007) and after (in 2008 and 2009) an extreme cold event (ECE) to determine the effects of the ECE on co‐occurrence patterns, spatiotemporal turnover and ecological processes in different functional groups (i.e. in‐faunal shelled deposit feeders [ISDFs] and hard‐bodied, mobile scavenger/predators [MS/Ps]).LocationSoutheast coasts of China.MethodWe used network analysis and null models to test the co‐occurrence patterns of the soil mollusc community. We used the analysis of distance and time decay to characterize the spatial turnover and temporal succession of the mollusc community based on presence/absence, relative abundance and biomass data. We performed random forest (RF), variation partitioning analysis (VPA) and Mantel tests to detect the effects of local environmental filtering and dispersal limitations on the soil mollusc community.ResultsWe found a decrease in species richness and biomass and an increase in abundance after an ECE, reflecting a significant change in mangrove soil mollusc communities. The network modularization, divergent succession and geographical differentiation of the ISDFs increased from 2008 to 2009, but environmental filtering and regional dispersal limitations decreased. The temporal trends of the network modules, geographical differentiation and dispersal limitations of MS/Ps followed a hump‐shaped pattern from 2008 to 2009, whereas the temporal trends of environmental filtering and temporal divergence exhibited an inverted hump‐shape pattern. The ECE changed the main environmental drivers of ISDFs and MS/Ps from water salinity to meteorology and vegetation factors.Main conclusionsMangrove soil mollusc communities in different functional groups invoked different spatiotemporal turnover models and ecological processes to shape unique co‐occurrence patterns in response to an ECE. We highlight the value of dividing different functional groups in developing predictive frameworks for a better understanding of community functional responses to global change.