Different Response of Arbuscular Mycorrhizal Fungal Communities in Roots and Rhizosphere Soil of Elymus Nutans to Long-term Warming in an Alpine Meadow

Elymus nutans is one of the most representative species in alpine meadows, characterized by its high nutrient content. The symbiosis between arbuscular mycorrhizal fungi (AMF) and plants can contribute to the functionality and stability of alpine meadow ecosystems under climate warming. However, the response of AMF communities in both rhizosphere soil and roots of Elymus nutans to long-term warming remains unclear. We conducted a 7-year field warming experiment to examine the effects of warming (+ 2 °C) on the composition of AMF communities in rhizosphere soil and plant roots of Elymus nutans . Warming increased rhizosphere soil organic carbon and available phosphorus content while also promoting mycorrhizal colonization. Furthermore, the number of unique amplicon sequence variants (ASVs) was higher in the rhizosphere soil samples compared to root samples. The dominant families found in both rhizosphere soil and root samples were Glomeraceae and Paralomeraceae . Warming significantly affected AMF communities in rhizosphere soil, increasing the diversity and the relative abundance of Glomeraceae. However, no significant changes were observed in AMF communities in Elymus nutans roots under warming conditions compared to control. Soil organic carbon strongly influenced AMF communities in rhizosphere soil, while NH 4 + -N and soil water content were correlated with AMF communities in roots. Long-term warming significantly altered the AMF community in the rhizosphere soil and had little effect on the AMF community of Elymus nutans roots.