Arbuscular mycorrhizal (AM) fungi affect ecosystem processes improving plant tolerance in (hyper)arid/saline environments. However, there are no previous studies on the presence of AM fungi in the Atacama Desert (Northern Chile), the driest desert in the world. Here, we studied the root and rhizosphere in 111 samples of representative plants from three elevation gradients: (i) hyperarid desert (700–2000 m a.s.l.), (ii) pre-Puna (2000–3100 m a.s.l.) and (iii) Puna (3100–4500 m a.s.l.) elevation belts. Soil pH, electrical conductivity (EC), organic matter, cations and the AM colonization and fungal structures were determined. All plants showed colonization and fungal structures. Root colonization ranged from 3.5 to 87%, hyphae showed densities from 0.13 to 204 m g⁻¹, and spore densities between 20 and 45,500 per 100 g of soil. The highest fungal structure abundances were found in Prosopis tamarugo, Baccharis scandens, Werneria pinnatifida, Deyeuxia curvula and Festuca deserticola rhizospheres. In general, EC and cations showed strong relationship with fungal structure abundance. Here, we reported for the first time the widespread presence of AM symbiosis in all the elevation belts of the Atacama Desert, constituting a first step to understand the ecological role that AM fungi play under extreme aridity and salinity conditions.

丛枝菌根（AM）真菌会影响生态系统过程，从而改善（高）干旱/盐碱环境下的植物耐受性。但是，以前没有关于在世界上最干燥的沙漠阿塔卡马沙漠（智利北部）中存在AM真菌的研究。在这里，我们研究了来自三个海拔梯度的111个代表性植物样品的根和根际：（i）高干旱沙漠（700–2000 m asl），（ii）普纳前（2000–3100 m asl）和（iii）普纳（3100–4500 m ASL）高程带。测定土壤的pH值，电导率（EC），有机质，阳离子以及AM的定殖和真菌结构。所有植物均显示出定植和真菌结构。根定植范围为3.5％至87％，菌丝显示密度为0.13至204 m g ^-1每100克土壤的孢子密度在20到45,500之间。最高的真菌结构丰度出现在塔氏疟原虫，Baccharis scandens，Werneria pinnatifida，Deyeuxia curvula和Festuca deserticola根际。通常，EC和阳离子与真菌结构丰度具有很强的关系。在这里，我们首次报道了在阿塔卡马沙漠的所有高程带中广泛存在AM共生现象，这是了解AM真菌在极端干旱和盐碱条件下发挥生态作用的第一步。