Introduction of species by humans breaks down biogeographic boundaries and results in the homogenization of species composition, yet empirical tests of this impact in marine forest ecosystems are still scarce. Large-scale planting aimed at reversing losses of mangroves has been the dominant strategy for mangrove restoration adopted by many organizations in the past decades, but there is a lack of quantitative understanding of the impacts of such large-scale plantings on mangrove biogeography. Here we used data collected before and after large-scale planting to compare the species richness and compositional similarities among 72 mangrove sites over a biogeographic scale (18-28°N) in China. After the large-scale planting, 15 of the mangrove species spread toward the higher latitudes, reflecting the geographical barriers of the mangrove plants have been broken. Local species richness of mangrove increased by 44.82% and biogeographic compositional similarity of mangroves increased by 13.33%, reflecting large-scale introduction and planting increase local diversity of mangrove but enhance biological homogenization. The dispersal limitation of mangrove communities reduced by 11.1%, which indicates that the community assemblage process of mangrove changed obviously. Worryingly, two alien species, Sonneratia apetala and Laguncularia racemosa, have dispersal across the biogeographic scale studied, reflecting an increase in the risk of biogeographic invasion. It is expected that biological homogeneity and species invasion will further influence the functional biogeography of mangroves. Our results highlight that mangrove biogeography is defined by human activities in the Anthropocene.

The frequency and intensity of climate extreme events are expected to increase with global warming in the future. Climate extreme events, such as an extreme cold event (ECE) will continue to influence the stability of soil fauna community biomass, since climate changes often cause a shift in community compositions and structures (e.g. biomass). Few studies, however, have addressed the effects of climate extreme events on the stability of soil fauna community biomass. A field investigation was conducted from 2007 to 2010 to assess the influence of an ECE on the biomass stability of the soil mollusc community across four mangrove wetlands (∼450 km) in South China. Distance-decay and time-decay were used to test the spatiotemporal dynamics of the community biomass. Network analysis and null model were performed to detect the importance of competitive interactions in shaping the stability of the soil mollusc community biomass. The ECE reduced the biomass of the soil mollusc community but increased the complexity of the spatiotemporal patterns of the community biomass. The ECE increased divergent temporal succession and spatial segregation in the soil mollusc community biomass, reflecting the spatiotemporal dynamics of the soil mollusc community biomass influenced by the ECE. Importantly, the ECE decreased the biomass stability of the soil mollusc community by an average of 34.17%. An increase in the modularity of an interactive network (by 75%) and a rise in the intensity of species competition were found after the ECE, reflecting that the ECE enhanced the competitive interactions of the soil mollusc community. The changes in the biomass stability of the soil mollusc community potentially impact their ability to provide ecosystem functions and services such as food production and carbon sequestration for humans. In general, these findings provide valuable ecological insights concerning the effects of climate extremes on the stability properties of ecological soil communities, thereby providing potential applications for soil management and predicting climate changes.

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This is an open access article under the terms of the Creat ive Commo ns Attri bution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

No abstract

No abstract

No abstract

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.