Adult trees cause density‐dependent mortality in conspecific seedlings by regulating the frequency of pathogenic soil fungi |
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| Authors: | Minxia Liang Xubing Liu Gregory S. Gilbert Yi Zheng Shan Luo Fengmin Huang Shixiao Yu |
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| Affiliation: | 1. Department of Ecology, School of Life Sciences/State Key Laboratory of Biocontrol, Sun Yat‐sen University, Guangzhou, China;2. Environmental Studies Department, University of California, Santa Cruz, CA, USA;3. Smithsonian Tropical Research Institute, Balboa, Ancón, Panama |
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| Abstract: | Negative density‐dependent seedling mortality has been widely detected in tropical, subtropical and temperate forests, with soil pathogens as a major driver. Here we investigated how host density affects the composition of soil pathogen communities and consequently influences the strength of plant‐soil feedbacks. In field censuses of six 1‐ha permanent plots, we found that survival was much lower for newly germinated seedlings that were surrounded by more conspecific adults. The relative abundance of pathogenic fungi in soil increased with increasing conspecific tree density for five of nine tree species; more soil pathogens accumulated around roots where adult tree density was higher, and this greater pathogen frequency was associated with lower seedling survival. Our findings show how tree density influences populations of soil pathogens, which creates plant‐soil feedbacks that contribute to community‐level and population‐level compensatory trends in seedling survival. |
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| Keywords: | Host density Janzen– Connell effect seedling survival soil‐borne plant pathogens subtropical forest |
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