Department of Ecology, School of Life Sciences and State Key Laboratory of Biocontrol, Sun Yat-sen University, Guangzhou, 510275, China.
Department of Earth and Environmental Sciences, The University of Manchester, Manchester, M13 9PT, UK.
Nat Commun. 2020 May 26;11(1):2636. doi: 10.1038/s41467-020-16507-y.
The mechanisms regulating community composition and local dominance of trees in species-rich forests are poorly resolved, but the importance of interactions with soil microbes is increasingly acknowledged. Here, we show that tree seedlings that interact via root-associated fungal hyphae with soils beneath neighbouring adult trees grow faster and have greater survival than seedlings that are isolated from external fungal mycelia, but these effects are observed for species possessing ectomycorrhizas (ECM) and not arbuscular mycorrhizal (AM) fungi. Moreover, survival of naturally-regenerating AM seedlings over ten years is negatively related to the density of surrounding conspecific plants, while survival of ECM tree seedlings displays positive density dependence over this interval, and AM seedling roots contain greater abundance of pathogenic fungi than roots of ECM seedlings. Our findings show that neighbourhood interactions mediated by beneficial and pathogenic soil fungi regulate plant demography and community structure in hyperdiverse forests.
调控物种丰富森林中群落组成和本地优势树种的机制仍不清楚，但与土壤微生物相互作用的重要性正日益得到认可。在这里，我们表明，通过与相邻成年树木下方土壤中根相关真菌菌丝相互作用的幼苗比与外部真菌菌丝隔离的幼苗生长更快，存活率更高，但这些效应仅在具有外生菌根（ECM）而非丛枝菌根（AM）真菌的物种中观察到。此外，十年来自然再生的 AM 幼苗的存活率与周围同种植物的密度呈负相关，而 ECM 树种幼苗的存活率在这段时间内呈正密度依赖性，并且 AM 幼苗的根中含有比 ECM 幼苗根更多的致病性真菌。我们的研究结果表明，由有益和致病性土壤真菌介导的邻域相互作用调节了高度多样化森林中的植物种群动态和群落结构。
