Ectomycorrhizal (EM) fungi play an important role in forest ecosystems. However, little is known about the mechanisms driving diversity and community composition of soil EM fungi in urban forest parks which are intensively affected by anthropogenic activities. In this study, we investigated the EM fungal community using Illumina high-throughput sequencing with soil samples collected from three typical forest parks, including Olympic Park, Laodong Park, and Aerding Botanical Garden of Baotou City. The results showed that soil EM fungi richness index followed a pattern of Laodong Park (146.43±25.17) > Aerding Botanical Garden (102.71±15.31) > Olympic Park (68.86±6.83). Russula, Geopora, Inocybe, Tomentella, Hebeloma, Sebacina, Amanita, Rhizopogon, Amphinema, and Lactarius were the dominant genera in the three parks. EM fungal community composition was significantly different among the three parks. Results of linear discriminant analysis effect size (LEfSe) indicated that all parks had biomarker EM fungi that exhibiting significantly different abundance. The normalized stochasticity ratio (NST) and the inferring community assembly mechanisms by phylogenetic-bin-based null model analysis (iCAMP) showed that both stochastic and deterministic processes determined soil EM fungal communities in the three urban parks, with a dominant role of the stochastic process. Drift and dispersal limitation in the stochastic process and homogeneous selection in the deterministic process were the dominant ecological processes of soil EM fungal community assembly in the three urban parks.
外生菌根(EM)真菌在森林生态系统中起重要作用。然而,人们对受人类活动密切影响的城市森林公园中土壤EM真菌的多样性、群落组成及维持机制还知之甚少。本文基于Illumina高通量测序对包头市奥林匹克公园、劳动公园和阿尔丁植物园3个典型的森林公园土壤中的EM真菌群落进行研究。结果表明: 3个公园土壤EM真菌的丰富度指数大小为劳动公园(146.43±25.17)> 阿尔丁植物园(102.71±15.31)> 奥林匹克公园(68.86±6.83);红菇属、地孔菌属、丝盖伞属、棉革菌属、粘滑菇属、蜡壳耳属、鹅膏属、须腹菌属、阿太菌属和乳菇属是3个公园的优势属;3个公园间EM真菌群落组成存在显著差异,线性判别分析效应大小(LEfSe)结果表明,所有公园都具有多度差异显著的标志EM真菌;标准化随机率(NST)和基于系统发育结合的零模型推断群落构建机制(iCAMP)分析显示,城市森林土壤EM真菌群落的构建由随机性过程和确定性过程共同驱动,但随机性过程占主导地位。随机过程中的漂变、扩散限制以及确定性过程中的同质化选择是这3个城市公园林下土壤EM真菌群落构建的主要生态学过程。.
Keywords: Baotou City; ecological process; ectomycorrhizal fungi; urban forest park.