Alterations of Arbuscular Mycorrhizal Fungal Diversity in Soil with Elevation in Tropical Forests of China

Mycorrhizas play a vital role in ecosystem function, diversity and productivity. However, mycorrhizas in tropical forests are considered to be a neglected area of research in contrast to the well-studied diversity patterns of macro organisms. To this end, soil samples from 0 to 30 cm in depth were collected from six or four elevations in a typical tropical forest of Mt. Jianfeng and Mt. Diaoluo in China. The arbuscular mycorrhizal fungal (AMF) diversity and community composition were explored among different elevations based on high-throughput barcoded sequencing on the Illumina MiSeq platform. Environmental variables of soil characteristics, and elevation on AMF community assembly were analyzed using canonical correspondence analysis. In total, 316 AMF operational taxonomic units (OTUs) were found to belong to four identified and one unclassified order, and Glomus was the most dominant genus in tropical forest. AMF communities or diversity did not clearly reflect local environmental conditions, the spatial distance between mountains and elevation. In total, 68% and 56% of taxa of AMF were observed on multiple elevations in Mt. Jianfeng and Mt. Diaoluo, respectively. Furthermore, 8.9% and 19% of OTUs were exhibited on all elevations in Mt. Jianfeng and Mt. Diaoluo, respectively. The AMF alpha diversity, richness and evenness were similar across the two surveyed tropical mountains. The influence of elevation showed no distinct role on the diversity of AMF taxa. Overall, AMF communities and diversity are abundant in tropical forests and with little influence of elevation in tropical forests of China.