Table_2_Molecular Diversity and Distribution of Arbuscular Mycorrhizal Fungi at Different Elevations in Mt. Taibai of Qinling Mountain.DOCX

Arbuscular mycorrhizal fungi (AMFs) play a vital role in ecosystems, especially in ecosystem variability, diversity, and function. Understanding the AMF diversity, distribution, and their driver at different altitudinal gradients is a benefit for understanding the ecological function of AMF in mountain ecosystems. In this study, we explored the AMF molecular diversity and their distribution from 660 to 3,500 m a.s.l. in Mount Taibai of Qinling Mountains based on high-throughput sequencing technology. A total of 702 operational taxonomic units (OTUs) in 103 species of AMF are isolated from soil samples, which belong to 18 identified and 1 unidentified genus in 10 families. The fungi in the genus of Glomus is the most dominant, with the occurrence frequency of 100% and the relative abundance of 42.268% and 33.048% on the species and OTU level, respectively. The AMF colonization in root could be simulated by a cubic function with the change of altitudes with the peak and trough at a.s.l. 1,170 and 2,850 m, respectively. Further, AMF diversity indices including Sob, Shannon diversity, and Pielou evenness also showed the same cubic function change trends with increasing altitude at OTU and species levels. However, the average values of diversity indices at OTU level are always higher than these at the species level. Based on the OTU level, the highest and lowest values of Shannon and Pielou indices are observed at the altitudes of 1,400 and 2,800 m, respectively. The pattern of AMF community distribution in Mt. Taibai is driven by altitude with the characteristics of more abundance in the medium- to low-altitude than high-altitude areas. In general, abundant AMF molecular diversity and species exit in different elevations of Mt. Taibai, which indicate gradient changes with elevations.

丛枝菌根真菌（AMFs）在生态系统中扮演着至关重要的角色，尤其是在生态系统变异性、多样性和功能方面。深入研究AMFs的多样性、分布及其在不同海拔梯度上的驱动因素，对于理解AMFs在山地生态系统中的生态功能具有重要意义。在本研究中，我们基于高通量测序技术，对秦岭太白山660至3,500米海拔范围内的AMFs分子多样性和分布进行了探索。从土壤样本中分离出702个操作分类单元（OTUs），涉及103种AMFs，分属于10个科中的18个已知属和1个未知属。其中，Glomus属的真菌最为突出，其出现频率为100%，在物种和OTU水平上的相对丰度分别为42.268%和33.048%。AMFs在根系中的定殖可以通过一个立方函数模拟，其峰值和谷值分别位于海拔1,170米和2,850米。此外，AMFs多样性指数，包括Sob指数、Shannon多样性和Pielou均匀度指数，在OTU和物种水平上也显示出随海拔增加而呈现的立方函数变化趋势。然而，在OTU水平上的多样性指数平均值始终高于物种水平上的平均值。基于OTU水平，Shannon和Pielou指数的最高和最低值分别出现在海拔1,400米和2,800米。太白山AMF群落分布的模式受海拔影响，呈现出中低海拔区域比高海拔区域更丰富的特点。总体而言，太白山不同海拔高度上存在着丰富的AMFs分子多样性和物种，这表明了随海拔变化的梯度特征。