PDF(Pubmed)
Abstract：
UNASSIGNED: Understanding patterns and processes of microbial biogeography in soils is important for monitoring ecological responses to human activities, particularly in ecologically vulnerable areas such as the Qinghai-Xizang Plateau. Highland barley is the staple food of local people and has mainly been cultivated along the Yarlung Zangbo River valley in Xizang.
UNASSIGNED: Here we investigated soil bacterial communities from 33 sampling sites of highland barley farmland in this region and compared them to those from wild ecosystems including alpine tundra, meadow, forest, and swamp. Additionally, the effects of environmental factors on bacterial communities, as well as the relative importance of stochastic and deterministic processes in shaping the beta diversity of soil bacterial communities in alpine ecosystems were assessed.
UNASSIGNED: In contrast to soils of wild ecosystems, these farmland samples harbored a highly homogeneous bacterial community without significant correlations with geographic, elevation, and edaphic distances. Discriminant bacterial taxa identified for farmland samples belong to Acidobacteria, with Acidobacteria Gp4 as the dominant clade. Although Acidobacteria were the most abundant members in all ecosystems, characterized bacterial taxa of meadow and forest were members of other phyla such as Proteobacteria and Verrucomicrobia. pH and organic matter were major edaphic attributes shaping these observed patterns across ecosystems. Null model analyses revealed that the deterministic assembly was dominant in bacterial communities in highland barley farmland and tundra soils, whereas stochastic assembly also contributed a large fraction to the assembly of bacterial communities in forest, meadow and swamp soils.
UNASSIGNED: These findings provide an insight into the consequences of human activities and agricultural intensification on taxonomic homogenization of soil bacterial communities in the Qinghai-Xizang Plateau.
UNASSIGNED: Here we investigated soil bacterial communities from 33 sampling sites of highland barley farmland in this region and compared them to those from wild ecosystems including alpine tundra, meadow, forest, and swamp. Additionally, the effects of environmental factors on bacterial communities, as well as the relative importance of stochastic and deterministic processes in shaping the beta diversity of soil bacterial communities in alpine ecosystems were assessed.
UNASSIGNED: In contrast to soils of wild ecosystems, these farmland samples harbored a highly homogeneous bacterial community without significant correlations with geographic, elevation, and edaphic distances. Discriminant bacterial taxa identified for farmland samples belong to Acidobacteria, with Acidobacteria Gp4 as the dominant clade. Although Acidobacteria were the most abundant members in all ecosystems, characterized bacterial taxa of meadow and forest were members of other phyla such as Proteobacteria and Verrucomicrobia. pH and organic matter were major edaphic attributes shaping these observed patterns across ecosystems. Null model analyses revealed that the deterministic assembly was dominant in bacterial communities in highland barley farmland and tundra soils, whereas stochastic assembly also contributed a large fraction to the assembly of bacterial communities in forest, meadow and swamp soils.
UNASSIGNED: These findings provide an insight into the consequences of human activities and agricultural intensification on taxonomic homogenization of soil bacterial communities in the Qinghai-Xizang Plateau.
摘要：
■了解土壤中微生物生物地理的模式和过程对于监测人类活动的生态反应非常重要，特别是在青藏高原等生态脆弱地区。高地大麦是当地人民的主食，主要在西藏的雅鲁藏布江流域种植。
■在这里，我们调查了该地区33个高地大麦农田采样点的土壤细菌群落，并将它们与包括高山苔原在内的野生生态系统进行了比较，草甸,森林,还有沼泽.此外,环境因素对细菌群落的影响，以及随机和确定性过程在塑造高山生态系统土壤细菌群落β多样性中的相对重要性。
■与野生生态系统的土壤相比，这些农田样本具有高度同质的细菌群落，与地理没有显着相关性，高程,和edaphic距离。为农田样品鉴定的判别细菌类群属于酸性细菌，以酸杆菌Gp4为优势枝。尽管酸细菌是所有生态系统中最丰富的成员，以草地和森林为特征的细菌类群是其他门的成员，例如变形杆菌和Verrucomicrobia。pH和有机质是塑造整个生态系统中这些观察到的模式的主要土壤属性。空模型分析表明，确定性组装在高地大麦农田和苔原土壤的细菌群落中占主导地位，而随机组装对森林中细菌群落的组装也贡献了很大一部分，草地和沼泽土壤。
■这些发现为人类活动和农业集约化对青藏高原土壤细菌群落分类均质化的影响提供了见解。
■在这里，我们调查了该地区33个高地大麦农田采样点的土壤细菌群落，并将它们与包括高山苔原在内的野生生态系统进行了比较，草甸,森林,还有沼泽.此外,环境因素对细菌群落的影响，以及随机和确定性过程在塑造高山生态系统土壤细菌群落β多样性中的相对重要性。
■与野生生态系统的土壤相比，这些农田样本具有高度同质的细菌群落，与地理没有显着相关性，高程,和edaphic距离。为农田样品鉴定的判别细菌类群属于酸性细菌，以酸杆菌Gp4为优势枝。尽管酸细菌是所有生态系统中最丰富的成员，以草地和森林为特征的细菌类群是其他门的成员，例如变形杆菌和Verrucomicrobia。pH和有机质是塑造整个生态系统中这些观察到的模式的主要土壤属性。空模型分析表明，确定性组装在高地大麦农田和苔原土壤的细菌群落中占主导地位，而随机组装对森林中细菌群落的组装也贡献了很大一部分，草地和沼泽土壤。
■这些发现为人类活动和农业集约化对青藏高原土壤细菌群落分类均质化的影响提供了见解。
