School of Life Sciences, Hebei University, Baoding 071002, China; College of Traditional Chinese Medicine, Hebei University, Baoding 071002, China.
Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100193, China.
Microbiol Res. 2023 Apr;269:127315. doi: 10.1016/j.micres.2023.127315. Epub 2023 Feb 1.
Assessment changes of soil microbial community structure and function is important in understanding the response to desert ecosystem management. In present study, variations of soil microbial community and edaphic factors associated with five desert shrubs were determined in Anxi extremely arid desert in Northwest China in growing (summer), deciduous (autumn), and snowfall (winter) seasons. For that, the microbial composition and catabolic metabolism were examined using methods of phospholipid fatty acid (PLFA) and Biolog EcoPlate, respectively. Regardless of plant species and seasonal patterns, the microbial community was mostly dominated by gram-negative bacteria (GN); and the carbohydrates, amino acids and polymers were the main carbon sources for desert microbial metabolism. Microbial biomass and metabolic levels were significantly higher in both summer and winter than those of autumn. There was no correlation between soil microbial community and carbon utilization in winter; but GN was positively correlated with metabolism of amines carbon sources in summer, while fungal community presented the strongest correlation with suites of carbon sources' metabolic levels in autumn, indicating the uncoupled relationship between microbial community and function in desert ecosystems. Desert shrubs significantly influenced the composition of soil microbial community, whereas the variation of microbial catabolic metabolism was most attributed to seasonality. Nevertheless, the effects of both plant species (21.3 %) and climate variation (84.9 %) interacted with soil properties, indicating the seasonality of soil nutrients predominately determined the changes in composition and metabolism of desert microbes. Both the comprehensive seasonal level and the intra-seasonal paired correlation analysis proved that phosphorus was the key factor in determining microbial community composition, while ammonia and nitrate nitrogen were more correlated to microbial functional metabolism. Additionally, soil moisture and organic carbon in desert environment also induced the shifts in ratio of fungi and bacterial communities. We conclude that the seasonal patterns of soil microbial community and metabolic function in extremely arid desert are predictable, and mainly influenced by specific soil factors driven by desert shrubs and climate factors. These findings will provide a basis for evaluating the management of soil resources and microbial function in desert environments.
评估土壤微生物群落结构和功能的变化对于理解荒漠生态系统管理的响应非常重要。本研究在中国西北极端干旱的安西荒漠中，在生长季（夏季）、落叶季（秋季）和降雪季（冬季），确定了与五种荒漠灌木相关的土壤微生物群落和土壤因子的变化。为此，使用磷脂脂肪酸（PLFA）和 Biolog EcoPlate 方法分别检测了微生物组成和分解代谢。无论植物种类和季节模式如何，微生物群落主要由革兰氏阴性菌（GN）主导；碳水化合物、氨基酸和聚合物是荒漠微生物代谢的主要碳源。夏季和冬季的微生物生物量和代谢水平明显高于秋季。冬季土壤微生物群落与碳利用之间没有相关性；但是夏季 GN 与胺类碳源的代谢呈正相关，而真菌群落与秋季碳源代谢水平的综合相关性最强，表明荒漠生态系统中微生物群落与功能之间存在解耦关系。荒漠灌木显著影响土壤微生物群落的组成，而微生物分解代谢的变化主要归因于季节性。然而，植物种类（21.3%）和气候变化（84.9%）的影响与土壤特性相互作用，表明土壤养分的季节性主要决定了荒漠微生物组成和代谢的变化。综合季节性水平和季节内配对相关分析均表明，磷是决定微生物群落组成的关键因素，而氨氮和硝氮与微生物功能代谢的相关性更强。此外，荒漠环境中的土壤水分和有机碳也导致了真菌和细菌群落比例的变化。我们得出结论，极端干旱荒漠土壤微生物群落和代谢功能的季节性模式是可预测的，主要受荒漠灌木和气候因素驱动的特定土壤因素的影响。这些发现将为评估荒漠环境中土壤资源和微生物功能的管理提供依据。
