State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China ; University of Chinese Academy of Sciences, Beijing, China.
PLoS One. 2013 Sep 26;8(9):e76447. doi: 10.1371/journal.pone.0076447. eCollection 2013.
Arbuscular mycorrhizal (AM) fungi form symbiotic associations with most plant species in terrestrial ecosystems, and are affected by environmental variations. To reveal the impact of disturbance on an AM fungal community under future global warming, we examined the abundance and community composition of AM fungi in both soil and mixed roots in an alpine meadow on the Qinghai-Tibetan Plateau, China. Warming and grazing had no significant effect on AM root colonization, spore density and extraradical hyphal density. A total of 65 operational taxonomic units (OTUs) of AM fungi were identified from soil and roots using molecular techniques. AM fungal OTU richness was higher in soil (54 OTUs) than in roots (34 OTUs), and some AM fungi that differed between soil and roots, showed significantly biased occurrence to warming or grazing. Warming and grazing did not significantly affect AM fungal OTU richness in soil, but warming with grazing significantly increased AM fungal OTU richness in roots compared to the grazing-only treatment. Non-metric multidimensional scaling analysis showed that the AM fungal community composition was significantly different between soil and roots, and was significantly affected by grazing in roots, whereas in soil it was significantly affected by warming and plant species richness. The results suggest that the AM fungal community responds differently to warming and grazing in soil compared with roots. This study provides insights into the role of AM fungi under global environmental change scenarios in alpine meadows of the Qinghai-Tibetan Plateau.
丛枝菌根（AM）真菌与陆地生态系统中的大多数植物物种形成共生关系，并受到环境变化的影响。为了揭示未来全球变暖对 AM 真菌群落的干扰影响，我们在中国青藏高原高寒草甸调查了土壤和混合根系中 AM 真菌的丰度和群落组成。增温和放牧对 AM 根定殖、孢子密度和根外菌丝密度没有显著影响。利用分子技术从土壤和根部分别鉴定出 65 个 AM 真菌的操作分类单元（OTUs）。土壤中的 AM 真菌 OTU 丰富度（54 个 OTUs）高于根系（34 个 OTUs），土壤和根系之间存在一些 AM 真菌，它们对增温和放牧的出现有明显的偏向性。增温和放牧对土壤中 AM 真菌 OTU 丰富度没有显著影响，但与单独放牧相比，增温和放牧显著增加了根系中 AM 真菌 OTU 的丰富度。非度量多维标度分析表明，AM 真菌群落组成在土壤和根系之间存在显著差异，在根系中受到放牧的显著影响，而在土壤中则受到增温和植物物种丰富度的显著影响。研究结果表明，AM 真菌在土壤和根系中对增温和放牧的反应不同。本研究为青藏高原高寒草甸 AM 真菌在全球环境变化情景下的作用提供了新的见解。
