Cyanobacteria are among the first photoautotrophic component of soil microorganism communities which play a key ecological role in nutrient cycles and soil productivity. However, the sustainability of these soil biodiversity ecosystem services is increasingly compromised, especially in urban and peri-urban areas where soils are heavily exploited and used for a wide range of human activities. The aim of this study is to assess the impact of different types of human disturbances on cyanobacteria diversity and distribution in suburban soils of Marrakesh. Soil and cyanobacteria sampling were carried out during two campaigns at six sites located along an anthropogenic gradient from the least urbanized suburbs of Marrakesh to the highly anthropized suburban area. In the laboratory, soil physicochemical characteristics were measured. The morphological identification of cyanobacteria species was based both on microscopic observation and on soil cultures in solid and liquid Z8 media. The results showed a total of 25 cyanobacteria taxa belonging to ten genera, four families, and two orders (Oscillatoriales 88% and Chroococcales 12% of taxa). Among the taxa identified, seven strains were isolated in soil culture in nutrient media and purified in monoalgal culture. The highest cyanobacterial diversity was recorded in irrigated soil with treated wastewater compared to the non-cultivated control soil. In Principal Component and Cluster Analysis, suburban soils were subdivided into three groups depending on the chemical properties and cyanobacteria composition. Cyanobacteria diversity was significantly associated with the soil moisture, total organic carbon (TOC), PO4-P, NO3-N, and NH4-N contents. While diversity and microalgal biomass were significantly lower in the soils affected by municipal and mining solid wastes, the input of organic matter and nutrients from treated wastewater appears to be beneficial for the increasing of the biodiversity of soil cyanobacteria. This survey provides a first inventory of the soil cyanobacterial communities and shows their spatial variability and high sensitivity to the land-use practices and anthropogenic disturbances on urban soil in Moroccan drylands.

中文翻译：

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人为干扰对摩洛哥马拉喀什郊区干旱区土壤蓝藻多样性和分布的影响

蓝藻是土壤微生物群落中最早的光合自养成分之一，在养分循环和土壤生产力中起着关键的生态作用。然而，这些土壤生物多样性生态系统服务的可持续性越来越受到损害，特别是在土壤被大量开发并用于广泛人类活动的城市和城郊地区。本研究的目的是评估不同类型的人类干扰对马拉喀什郊区土壤中蓝藻多样性和分布的影响。土壤和蓝细菌采样是在两个活动期间在六个地点进行的，这些地点沿着从马拉喀什城市化程度最低的郊区到高度人为化的郊区的人为梯度。在实验室中，测量土壤理化特性。蓝藻物种的形态学鉴定基于显微镜观察和固体和液体 Z8 培养基中的土壤培养。结果显示共有25个蓝藻类群，属于10个属、4个科和2个目（Oscillatoriales 88%和Chroococcales 12%）。在鉴定的分类群中，在营养培养基的土壤培养中分离出 7 个菌株，并在单藻培养中纯化。与未栽培的对照土壤相比，在处理过废水的灌溉土壤中记录了最高的蓝藻多样性。在主成分和聚类分析中，郊区土壤根据化学性质和蓝藻组成细分为三组。蓝藻多样性与土壤水分、总有机碳 (TOC)、PO4-P、NO3-N、和 NH4-N 含量。虽然受市政和采矿固体废物影响的土壤中的多样性和微藻生物量显着降低，但来自处理过的废水的有机物质和养分的输入似乎有利于增加土壤蓝藻的生物多样性。该调查提供了土壤蓝藻群落的第一个清单，并显示了它们的空间变异性和对摩洛哥旱地城市土壤的土地利用实践和人为干扰的高度敏感性。