Indirect effects of non‐native Spartina alterniflora and its fungal pathogen (Fusarium palustre) on native saltmarsh plants in China. (12th July 2014)

• Record Type: Journal Article
• Authors: Li, Hui; Zhang, Xiameng; Zheng, Rushui; Li, Xiao; Elmer, Wade H.; Wolfe, Lorne M.; Li, Bo; Mack, Richard
• Is Part Of: Journal of ecology. Volume 102:Number 5(2014:Sep.)
• Page Start: 1112
• Page End: 1119
• Publication Date: 2014-07-12
• Subjects: Plant ecology -- Periodicals; 577.05
• DOI: 10.1111/1365-2745.12285
• Languages: English
• ISSNs: 0022-0477

Abstract

<abstract abstract-type="main" id="jec12285-abs-0001"> <title>Summary</title> <p> <list id="jec12285-list-0001" list-type="order"> <list-item> <p>Pathogens can affect their hosts and change community composition and structure. Pathogens may be key determinants of biological invasions. However, few empirical studies exist examining how non‐native plants drive their invasions through indirect effects involved with pathogens. Here, indirect effects refer to how one species alters the effect that another species has on a third.</p> </list-item> <list-item> <p> <italic>Fusarium palustre</italic> was associated with the dieback of <italic>Spartina alterniflora</italic> in its native North American saltmarshes. Native plant <italic>Phragmites australis</italic> was also found to die back in the Dongtan wetland of the Chinese Yangtze River estuary invaded by non‐native <italic>Spartina alterniflora</italic>. This phenomenon suggests that <italic>Spartina</italic> might not escape from its pathogen when being introduced from its native North America and has indirectly caused the dieback of <italic>Phragmites</italic> in China.</p> </list-item> <list-item> <p>To investigate the indirect effect of <italic>Spartina</italic> involving <italic>Fusarium</italic>, we sampled plants and soils in dieback patches to isolate the pathogen. Next, we used an artificial inoculation study to determine the virulence of <italic>Fusarium</italic> to both <italic>Phragmites</italic> and <italic>Spartina</italic>. Finally, the spatial distribution of <italic>Fusarium</italic> was studied through examining its incidence in saltmarshes along the east coast of China.</p> </list-item> <list-item> <p>The endophytic fungus <italic>F. palustre</italic> was found to be closely associated with <italic>Phragmites</italic> dieback in the Dongtan wetland and it is likely that it was transported by non‐native <italic>Spartina</italic> from its native North American saltmarshes to the Chinese saltmarshes. The spillover of <italic>F. palustre</italic> from non‐native <italic>Spartina</italic> to native <italic>Phragmites</italic> might subsequently facilitate <italic>Spartina</italic> invasion.</p> </list-item> <list-item> <p> <italic>Synthesis</italic>. Invasive plants do not only directly compete with native plants, but also indirectly cause pathogen infection on the latter, by acting as vectors and reservoirs for pathogens shared with native plants. Our findings highlight the significance of indirect effects involving pathogens in biological invasions. It is necessary to consider these pathogen‐mediated indirect effects of non‐native plant species in multi‐host‐pathogen systems for management and restoration purposes.</p> </list-item> </list> </p> </abstract>