Northeast Asia Ecosystem Carbon Sink Research Center (NACC), Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, School of Ecology, Northeast Forestry University, Harbin, 150040, China.
Shanghai Engineering Research Center of Sustainable Plant Innovation, Shanghai Botanical Garden, Shanghai, 200030, China.
J Environ Manage. 2024 Nov;370:122428. doi: 10.1016/j.jenvman.2024.122428. Epub 2024 Sep 10.
Soil microbial diversity is crucial for regulating biogeochemical cycles, including soil carbon (C) dynamics and nutrient cycling. However, how climate, plants, and soil properties influence the microbiome in forests remains unclear, especially at the continental scale, hindering us to better understand forest C-climate change feedback. Here, we investigated the spatial patterns of microbial diversity across China's forests and explored the controlling factors of microbial β diversity and network complexity. Our results showed that soil pH strongly influenced bacterial and fungal β diversity compared to climate, soil nutrient and plant properties. To further investigate the environmental preference of the microbial networks, we classified the amplicon sequence variants (ASVs) into five groups ranging from acidic to alkaline soils. Co-occurrence network analysis revealed that the topological structure of the bacterial network (e.g., edge and degree) increased with pH and was negatively correlated with β diversity but not for fungal diversity. Soil fungi exhibited higher β diversity and network complexity (i.e., degree and betweenness) than bacteria in acidic soils (pH < 5.1), and vice versa in neutral and alkaline soils (pH > 5.5). Within the pH range of 5.1-5.5, the bacterial-fungal network displayed the highest network complexity with the lowest fungal β diversity, and significant positive correlations were found between fungal β diversity and soil properties. In addition, bacterial growth in acidic soil (pH < 5.5) showed positive correlations with acid phosphatase (AP), but negative ones with β-1,4-glucosidase (BG), and vice versa in neutral and alkaline soils (pH > 5.5). Furthermore, 46 bacterial core species were identified, and their abundance had significant correlation with soil pH. These findings highlight the critical role of soil pH in driving soil microbial β diversity across China's forests and reveal the effects of pH thresholds on changes in the soil microbial network and core species.
土壤微生物多样性对于调节生物地球化学循环至关重要，包括土壤碳（C）动态和养分循环。然而，气候、植物和土壤特性如何影响森林中的微生物组尚不清楚，特别是在大陆尺度上，这阻碍了我们更好地理解森林 C-气候变化反馈。在这里，我们调查了中国森林中微生物多样性的空间格局，并探讨了微生物 β多样性和网络复杂性的控制因素。我们的结果表明，与气候、土壤养分和植物特性相比，土壤 pH 强烈影响细菌和真菌的 β 多样性。为了进一步研究微生物网络的环境偏好，我们将扩增子序列变异体（ASV）分为从酸性到碱性土壤的五个组。共生网络分析显示，细菌网络的拓扑结构（例如，边缘和度）随着 pH 值的增加而增加，与 β 多样性呈负相关，但与真菌多样性无关。在酸性土壤（pH<5.1）中，土壤真菌表现出更高的 β 多样性和网络复杂性（即度和介数），而在中性和碱性土壤（pH>5.5）中则相反。在 pH 值为 5.1-5.5 的范围内，细菌-真菌网络显示出最高的网络复杂性，真菌的 β 多样性最低，并且真菌 β 多样性与土壤特性之间存在显著的正相关关系。此外，酸性土壤（pH<5.5）中细菌的生长与酸性磷酸酶（AP）呈正相关，而与β-1,4-葡萄糖苷酶（BG）呈负相关，而在中性和碱性土壤（pH>5.5）中则相反。此外，鉴定出 46 个细菌核心种，其丰度与土壤 pH 值显著相关。这些发现突出了土壤 pH 值在中国森林土壤微生物 β 多样性中的关键作用，并揭示了 pH 阈值对土壤微生物网络和核心物种变化的影响。
