Fertile islands play an important role in ecosystem structure and function. However, studies on the effects of fine roots of desert shrubson fertile islands in contrasting textured soils are scarce. We investigated soil water and nutrient contents, microbial biomass, fine root densities of Haloxylon ammodendron (C.A.Mey.), and their enrichment indices along a soil profile (100 cm deep and 200 cm wide) in two soils: Torripsamment (coarse-textured) and Haplocalcid (fine-textured). In both soils, water and nutrient contents, microbial biomass, and fine root densities decreased with increasing distance from the taproot. Their enrichment indices exceeded 1.0, except at the 190 cm distance from the taproot. Compared with the Haplocalcid, the Torripsamment had higher enrichment levels for all parameters, which mainly occurred at 0–20 and 20–60 cm depths. The enrichment indices of fine root densities were positively related to those of soil variables at similar depths, and the relationships were more intense in the Torripsamment than in the Haplocalcid at 0–20 and 20–60 cm depths. These results suggest that fine root distribution along the soil profile promotes fertile islands extending from the surface to deep soils. Soil texture affects fine root distribution and consequently modulates the intensity of fertile islands.

肥沃的岛屿在生态系统的结构和功能中起着重要作用。但是，关于荒漠灌木丛肥沃岛屿的细根对对比有纹理的土壤的影响的研究很少。我们调查了土壤水分和养分含量，微生物生物量，梭梭细根密度（CAMey。），以及它们在两种土壤中沿土壤剖面（深100厘米和宽200厘米）的富集指数：龟裂（粗纹理）和单倍骨（细纹理）。在两种土壤中，水和养分含量，微生物生物量和细根密度都随着距主根距离的增加而降低。它们的富集指数超过1.0，但距主根的距离为190 cm。与Haplocalcid相比，Torripsamment对所有参数的富集水平更高，主要发生在0–20和20–60 cm深度。细根密度的富集指数与相似深度的土壤变量的富集指数正相关，并且在0至20厘米和20至60厘米深度处，龟裂中的关系比单倍体中的关系更紧密。这些结果表明，沿土壤剖面的精细根分布促进了肥沃的岛屿从表面扩展到深层土壤。土壤质地会影响根系的分布，从而调节肥沃岛屿的强度。