Arbuscular mycorrhizal fungal communities under gradients of grazing in Mongolian grasslands of different aridity
Arbuscular mycorrhizal fungal communities under gradients of grazing in Mongolian grasslands of different aridity
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DOI：
10.1007/s00572-018-0855-7
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发表时间：
2018-10-01
期刊：
影响因子：
3.9
通讯作者：
Yamato, Masahide
中科院分区：
文献类型：
--
作者：
Kusakabe, Ryota;Taniguchi, Takeshi;Yamato, Masahide
对内蒙古草原丛枝菌根真菌（AM）群落在放牧强度梯度下的分布特征进行了研究：内蒙古胡斯泰国家公园（胡斯泰）的山地森林草原、曼达尔戈维和布尔干的荒漠草原。放牧强度分为轻度放牧（LG）、中度放牧（MG）和重度放牧（HG） 3类。在区系组成上，放牧降低了禾本科植物的地上部生物量，其中以针茅（Stipa spp）的生物量最大。3个研究点AM真菌群落存在差异，但大部分AM真菌操作分类单元（OTUs）普遍存在，占总reads的1.0%以上。这表明AM真菌群落可能来源于相似的AM真菌区系，并与环境因子相对应。不同放牧强度下AM真菌群落组成差异显著。各样地最优势AM真菌OTU相对丰度随放牧强度的增加而降低。最优势AM真菌OTUs的平均比例也随放牧强度的增加而降低。单一AM真菌分类群的优势可能是AM真菌共生的典型生态特征，放牧干扰了AM真菌的群落结构。
Communities of arbuscular mycorrhizal (AM) fungi in Mongolian grassland were characterized under gradients of grazing intensity at three study sites of different aridity: mountain forest steppe at Hustai National Park (Hustai), and desert steppe at Mandalgovi and Bulgan. Grazing intensity was classified into three categories: lightly grazed (LG), moderately grazed (MG), and heavily grazed (HG). With regard to floristic composition, grazing decreased the shoot biomass of Poaceae species, especially Stipa spp. Distinctness of the AM fungal communities was observed among the three study sites, but most of the AM fungal operational taxonomic units (OTUs) that comprised over 1.0% of the total reads were ubiquitous. This result indicates that the AM fungal communities may be derived from similar AM fungal floras in correspondence with environmental factors. The composition of AM fungal communities differed significantly among the grazing intensities at all study sites. The relative abundance of the most dominant AM fungal OTU of the LG plots decreased with an increase in grazing intensity at all study sites. The mean proportions of the most dominant AM fungal OTUs also decreased with increased grazing intensity at Hustai. Dominance by a single AM fungal taxon may be a typical ecological feature of the AM fungal symbiosis, and grazing disturbs AM fungal community structure.