Abstract Biocrusts presented their highest expression in the inter-patches. However, an increase in the level of aridity along the landscape could lead to vascular plants to make a notable influence on the spatial distribution of biocrusts. Our objective was to determine the spatial variation of the vascular plant interactions with biocrusts, and the individual variations of biocrusts and each of its components along a gradient of aridity in Argentina. We worked on three sites following a semiarid-arid-hyperarid environmental aridity gradient. We established 15 plots along the stress gradient. In each plot, we evaluated the spatial distribution of cyanobacteria, mosses, and lichens and the interaction with the dominant shrubs using a distance index analysis. The hyperarid site showed an aggregate distribution pattern for each biological group (biocrusts, mosses, lichens, and cyanobacteria). The semiarid site showed an aggregate distribution for mosses and cyanobacteria. Respect to the interaction with the shrubs, only the hyperarid site showed a positive interaction between shrubs and the components of biocrusts. We found positive interactions of lichens on the semiarid site, but the arid studied site did not show interactions. Reductions in vegetation cover could directly influence in the biocrust coverage, generating impacts on ecosystems.

中文翻译：

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阿根廷中西部干旱梯度生物土壤结皮的空间分布

摘要 生物结壳在斑块间表达最高。然而，沿景观干旱程度的增加可能导致维管植物对生物结皮的空间分布产生显着影响。我们的目标是确定维管植物与生物结皮相互作用的空间变化，以及生物结皮及其每个成分在阿根廷干旱梯度上的个体差异。我们在遵循半干旱-干旱-超干旱环境干旱梯度的三个地点开展工作。我们沿应力梯度建立了 15 个图。在每个地块中，我们使用距离指数分析评估了蓝藻、苔藓和地衣的空间分布以及与优势灌木的相互作用。超干旱地区显示出每个生物群（生物结皮、苔藓、地衣和蓝藻）的聚集分布模式。半干旱地区显示出苔藓和蓝藻的聚集分布。就与灌木的相互作用而言，只有超干旱地区表现出灌木与生物结皮成分之间的正相互作用。我们在半干旱地区发现了地衣的积极相互作用，但干旱研究地区没有表现出相互作用。植被覆盖的减少会直接影响生物地壳的覆盖，从而对生态系统产生影响。只有超干旱地区显示了灌木和生物结皮成分之间的正相互作用。我们在半干旱地区发现了地衣的积极相互作用，但干旱研究地区没有表现出相互作用。植被覆盖的减少会直接影响生物地壳的覆盖，从而对生态系统产生影响。只有超干旱地区显示了灌木和生物结皮成分之间的正相互作用。我们在半干旱地区发现了地衣的积极相互作用，但干旱研究地区没有表现出相互作用。植被覆盖的减少会直接影响生物地壳的覆盖，从而对生态系统产生影响。