Elevation, but not phosphorus, shapes arbuscular mycorrhizal fungal colonization of plateau wetland plants: A case study of the Qinghai-Tibet Plateau

Plateau wetlands play an important role in protecting biodiversity and regulating runoff and local climate, especially on the Qinghai-Tibet Plateau. Arbuscular mycorrhizal fungi (AMF) can colonize the roots of wetland plants and affect their ecological function. To investigate AMF colonization of wetland plants on the Qinghai-Tibet Plateau, we conducted a field survey of the South-Tibet River Basin across a sampling distance of >1 000 km and an elevational range of 4 000 to 5 000 m. A total of 130 AMF OTUs was detected in sediment samples. In addition, a negative correlation was found between elevation and AMF relative abundance in sediment based on generalized linear mixed model analysis, and AMF colonization also decreased significantly with elevation from 4 046 to 5 157 m. Structural equation model analysis showed that AMF colonization, relative abundance, and richness in sediments were directly affected by elevation, but not significantly impacted by total phosphorus content in sediments. To the best of our knowledge, this study is the first to investigate AMF colonization in wetland plants on a high-elevation plateau (>4 000 m). Our findings have important implications for understanding the interactions between AMF and Qinghai-Tibet Plateau wetland plants.