Department of Earth and Environmental Sciences, Korea University, Seoul 02841, South Korea.
School of Civil, Environmental and Architectural Engineering, Korea University, Seoul 02841, South Korea.
Sci Total Environ. 2021 Nov 25;797:148944. doi: 10.1016/j.scitotenv.2021.148944. Epub 2021 Jul 16.
The land-use change from natural to managed farmland ecosystems can undergo perturbations and significantly impact soil environment and communities. To understand how anthropogenic land-use alteration determines in-depth relationships among soil environmental factors and soil bacterial communities, high-resolution characterization was performed using soil samples (27 spots × 3 depths; top 10-20 cm, middle 90-100 cm, bottom 180-190 cm) from a natural forest and a 50 year-old farmland. The soil bacterial community abundance (number of OTU's per sample) and diversity (Faith's phylogenetic diversity) was significantly higher in the top layer of farmland soil than in forest soil. However, the differences in bacterial community abundance between farmland and forest decreased with depth, suggesting that the effect of fertilization was limited to top and middle layers. The phyla Acidobacteria and Proteobacteria were distributed distinctively during the land-use change. The subgroups Gp1-3 of Acidobacteria were more abundant in the forest samples (pH 3.5-5), while Gp4-7 and Gp10 were predominant in the farmland (pH 4.5-9.5). Members belonging to α-Proteobacteria and Xanthomonadales in γ-Proteobacteria were dominant in the forest, whereas β-, δ-, and γ-Proteobacteria were relatively abundant in the farmland. Both multivariate and correlation network analyses revealed that Acidobacteria and Proteobacteria communities were significantly affected by soil pH, as well as toxic metals from pesticides (Zn, Cr, Ni, Cu, Cd, As) and terminal electron acceptors (NO, bioavailable Fe(III), SO). In line with the long history of anthropogenic fertilization, the farmland site showed high abundance of membrane and ATP-binding cassette transporter genes, suggesting the key for uptake of nutrients and for protection against toxic metals and environmental stresses. This study provides new insights into the use of both Acidobacteria and Proteobacteria community structures as a bacterial indicator for land-use change.
从自然到管理农田生态系统的土地利用变化会经历干扰，并对土壤环境和群落产生重大影响。为了了解人为土地利用变化如何决定土壤环境因子和土壤细菌群落之间的深入关系，我们对天然林和 50 年农田的土壤样本（27 个点×3 个深度；表层 10-20cm、中层 90-100cm、底层 180-190cm）进行了高分辨率的特征描述。农田土壤表层的土壤细菌群落丰度（每个样本的 OTU 数量）和多样性（Faith 的系统发育多样性）明显高于森林土壤。然而，农田和森林土壤细菌群落丰度的差异随深度而减小，这表明施肥的影响仅限于表层和中层。在土地利用变化过程中，酸杆菌门和变形菌门分布明显不同。酸杆菌门的 Gp1-3 亚群在森林样本中更为丰富（pH 3.5-5），而 Gp4-7 和 Gp10 则在农田中占优势（pH 4.5-9.5）。属于α-变形菌门和γ-变形菌门的Xanthomonadales的成员在森林中占优势，而β-、δ-和γ-变形菌门在农田中相对丰富。多元和相关网络分析都表明，酸杆菌门和变形菌门群落受到土壤 pH 值以及农药（Zn、Cr、Ni、Cu、Cd、As）和末端电子受体（NO、可利用的 Fe（III）、SO）中有毒金属的显著影响。与长期的人为施肥历史相一致，农田样地表现出高丰度的膜和 ATP 结合盒转运蛋白基因，这表明了吸收养分和抵御有毒金属和环境压力的关键。本研究为利用酸杆菌门和变形菌门群落结构作为土地利用变化的细菌指标提供了新的见解。
