Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR-CONICET, Provincia de La Rioja, UNLAR, SEGEMAR, UNCa), Entre Ríos y Mendoza s/n, 5301, Anillaco La Rioja, Argentina.
Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y de Diagnóstico (CEBBAD), Departamento de Ciencias Naturales y Antropológicas, CONICET, Buenos Aires, Argentina.
Microb Ecol. 2019 Feb;77(2):451-459. doi: 10.1007/s00248-018-1227-8. Epub 2018 Jul 12.
Subterranean rodents are considered major soil engineers, as they can locally modify soil properties by their burrowing activities. In this study, the effect of a subterranean rodent of the genus Ctenomys on soil properties and root endophytic fungal propagules in a shrub desert of northwest Argentina was examined. Our main goal was to include among root endophytic fungi not only arbuscular mycorrhiza but also the dark septate endophytes. We compared the abundance of fungal propagules as well as several microbiological and physicochemical parameters between soils from burrows and those from the surrounding landscape. Our results show that food haulage, the deposition of excretions, and soil mixing by rodents' burrowing promote soil patchiness by (1) the enrichment in both types of root endophytic fungal propagules; (2) the increase in organic matter and nutrients; and (3) changes in soil edaphic properties including moisture, field capacity, and texture. These patches may play a critical role as a source of soil heterogeneity in desert ecosystems, where burrows constructed in interpatches of bare soil can act, once abandoned, as "islands of fertility," promoting the establishment of plants in an otherwise hostile environment.
穴居啮齿动物被认为是主要的土壤工程师，因为它们的挖掘活动可以局部改变土壤性质。在这项研究中，我们研究了阿根廷西北部灌木荒漠中一种 Ctenomys 属的穴居啮齿动物对土壤性质和根内生真菌繁殖体的影响。我们的主要目标是将根内生真菌不仅包括丛枝菌根真菌，还包括深色有隔内生真菌。我们比较了洞穴土壤和周围景观土壤中真菌繁殖体的丰度以及几个微生物学和物理化学参数。研究结果表明，食物搬运、排泄物的沉积和啮齿动物的挖掘导致的土壤混合，通过（1）两种类型的根内生真菌繁殖体的富集；（2）有机质和养分的增加；以及（3）土壤物理性质的变化，包括水分、田间持水量和质地，促进了土壤斑块的形成。这些斑块可能在荒漠生态系统中作为土壤异质性的一个重要来源发挥关键作用，因为在光秃斑块之间建造的洞穴一旦被废弃，就可以成为“肥沃的岛屿”，促进植物在原本恶劣的环境中建立。
