This study profiles soil-inhabiting fungi across Saudi Arabia via PacBio-based metabarcoding

Deserts are home to diverse microbial communities important in many ecological processes and strategies for responding to changing climates. We recorded the biodiversity of soil-inhabiting fungi and their predictors in Saudi Arabia via metabarcoding. Alpha diversity of the fungal communities varied greatly, with high diversity in moist montane habitats and very low diversity in hyper-arid regions. The fungal community was dominated by members of the orders Pleosporales, Pezizales, Agaricales, Glomerales, and Sordariales, most of which represented saprotrophic guilds. Modelling analyses showed that soil pH, elevation, vegetation coverage, and vegetation indices substantially impact soil fungi's richness and community composition. These patterns mirror global dryland trends, with low diversity and high evenness in hyper-arid sites but higher richness and ecological differentiation in montane and vegetated regions. Our results demonstrate that vegetation cover, edaphic conditions, and altitude jointly shape fungal diversity in Arabian soils, offering mechanistic insight into community assembly and predicting ecosystem responses to climate change in arid landscapes.

沙漠孕育着多样的微生物群落，这类群落在诸多生态过程与气候变化应对策略中发挥着关键作用。本研究通过宏条形码（metabarcoding）技术，记录了沙特阿拉伯境内土壤栖居真菌的生物多样性及其影响因子。真菌群落的阿尔法多样性（Alpha diversity）差异显著：湿润山地生境中多样性水平较高，而超干旱区域的多样性则极低。该真菌群落以格孢菌目（Pleosporales）、盘菌目（Pezizales）、伞菌目（Agaricales）、球囊霉目（Glomerales）以及粪壳菌目（Sordariales）的类群为优势类群，其中多数类群属于腐生营养类群（saprotrophic guilds）。建模分析结果显示，土壤pH值、海拔、植被覆盖度以及植被指数对土壤真菌的丰富度与群落组成具有显著影响。这些格局与全球旱地生态系统的变化趋势一致：超干旱样地的多样性较低但均匀度（evenness）较高，而山地与植被覆盖区域的真菌丰富度更高且生态分化显著。本研究结果表明，植被覆盖、土壤条件（edaphic conditions）与海拔共同塑造了阿拉伯地区土壤中的真菌多样性，为理解干旱景观中的群落构建机制以及预测生态系统对气候变化的响应提供了机制性见解。