Human‐mediated dispersal redefines mangrove biogeography in the Anthropocene

Abstract

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.

Coupling near‐surface geomorphology with mangrove community diversity at the estuarine scale: A case study at Dongzhaigang Bay, China

“…(two), Acrostichum spp. (two), Xylocarpus (one), Nypa (one), Lumnitzera (one), Ceriops (one), Rhizophora (one), Excoecaria (one), Aegiceras (one), Avicennia (one), Kandelia (one) and Laguncularia (one) (Chen et al ., 2021). These genera differ greatly in structural morphology, including five different root types: pneumatophores, prop roots, knee roots, plank roots and fibrous roots (Fig.…”

Large‐scale changes in macrobenthic biodiversity driven by mangrove afforestation

“…afforestation, anthropogenic changes, biodiversity, distance-decay effect, habitat availability, mangrove crabs, mangrove molluscs, mangrove restoration afforestation will increase by 44.82% of local species richness of mangrove and increase by 13.33% of biogeographic compositional similarity of mangroves, reflecting change the structure and biogeographic pattern of mangrove plant communities (Chen, Gu, Lee, Wang, et al, 2021). However, the ecological effects of the largescale mangrove planting were not well studied.…”

“…The anthropogenic mangrove forests can provide additional habitat mosaic pattern for the colonization of marine benthic animals (Li et al, 2015; Marcus, 2005; Peng et al, 2009). A recent study conducted at a biogeographic scale (18–28°N) in China has found that large‐scale introduction and afforestation will increase by 44.82% of local species richness of mangrove and increase by 13.33% of biogeographic compositional similarity of mangroves, reflecting change the structure and biogeographic pattern of mangrove plant communities (Chen, Gu, Lee, Wang, et al, 2021). However, the ecological effects of the large‐scale mangrove planting were not well studied.…”

“…To enhance our understanding of ecological patterns and processes of the effect of mangrove afforestation, it is critical to conduct large‐scale research, which can provide more comprehensive insights and help reconcile conflicting findings (Baiser et al, 2012; Capinha et al, 2015). Furthermore, large‐scale research can inform the development of more effective management and conservation strategies by providing knowledge on regional or global patterns of biodiversity, ecosystem function and human impacts (Bernardo‐Madrid et al, 2019; Chen, Gu, Lee, Wang, et al, 2021). It is noteworthy that the impact of scaling mangrove afforestation on the regional biodiversity pattern of mangrove faunas is not well‐understood and warrants further investigation.…”

“…To remedy the degradation of mangroves and coastal erosion and control the invasion of the introduced cordgrass, Spartina alterniflora , large‐scale anthropogenic mangrove forests have been planted on the coast of southern China (Chen, Gu, Lee, Wang, et al, 2021; Liu et al, 2018; Ren et al, 2009). The unprecedented mangrove restorations along the Chinese intertidal zones give us an opportunity to detect how habitat addition and modification influence the biodiversity pattern of mangrove faunal and their maintenance mechanisms.…”