Differences in Metabolic Characteristics of Rhizosphere Fungal Community of Typical Arboreal, Shrubby and Herbaceous Species in Oasis of Arid Region

<i>Populus euphratica</i>, <i>Tamarix ramosissima</i>, and <i>Sophora alopecuroides</i> are, respectively, typical arboreal, shrubby, and herbaceous species in oases of arid regions. It is important to study the difference in metabolic characteristics of the rhizosphere fungal community of these plant species and their relationships with soil factors for the preservation of delicate arid oasis ecosystems with future environmental changes. In this study, we, respectively, collected 18 rhizosphere soil samples of <i>P. euphratica</i>, <i>T</i>. <i>ramosissima</i>, and <i>S. alopecuroides</i> to explore the difference in rhizosphere fungal metabolic characteristics of different plant life forms and their underlying driving factors. The results showed that (1) soil physicochemical properties (including soil water content, pH, etc.) were significantly different among different plant species (<i>p</i> < 0.05). (2) Rhizosphere fungal metabolic characteristics were significantly different between <i>S. alopecuroides</i> and <i>T. ramosissima</i> (ANOSIM, <i>p</i> < 0.05), which was mainly caused by the different utilization of carboxylic carbon. (3) The RDA showed that the main driving factors of the variations in rhizosphere fungal metabolic characteristics were different among different plant species. The main explanatory variables of the variations in the metabolic characteristics of the rhizosphere fungal community were carbon to nitrogen ratio (23%) and available potassium (17.4%) for <i>P. euphratica</i>, while soil organic carbon (23.1%), pH (8.6%), and total nitrogen (8.2%) for <i>T. ramosissima</i>, and soil clay content (36.6%) and soil organic carbon (12.6%) for <i>S. alopecuroides</i>. In conclusion, the variations in rhizosphere fungal metabolic characteristics in arid oases are dominantly affected by soil factors rather than plant life forms.