Habitat-specific environmental factors regulate spatial variability of soil bacterial communities in biocrusts across northern China's drylands
Habitat-specific environmental factors regulate spatial variability of soil bacterial communities in biocrusts across northern China's drylands
复制标题
特定生境的环境因素调节中国北方旱地生物结皮土壤细菌群落的空间变异
DOI：
10.1016/j.scitotenv.2020.137479
复制
发表时间：
2020-06-01
影响因子：
9.8
通讯作者：
Huang, Gang
中科院分区：
文献类型：
--
作者：
Su, Yan-gui;Liu, Jie;Huang, Gang
生物结壳是全球生态系统中常见的生物成分，它们含有多种土壤生物，能有效地增强土壤稳定性，发挥一系列重要的生态功能。然而，生物结壳中微生物群落的地理格局很少被评估，尽管它与旱地生态系统功能的空间变化密切相关。我们研究了中国北部4个生态系统(戈壁、荒漠、荒漠草原和草原)在降水梯度(16566.yr(-1))下生物结壳中的土壤细菌群落。细菌OTU数量和系统发育多样性并不是随着干旱程度的降低而线性增加，戈壁地区明显较低，荒漠、荒漠草原和草原之间差异不显著。戈壁和荒漠土壤细菌群落组成与荒漠草原和荒漠草原不同，戈壁和荒漠土壤细菌群落组成相似，说明生境在土壤细菌群落结构中起着关键作用。土壤细菌群落的地理格局受到地理距离和环境因素的强烈影响。4个生态系统细菌群落差异的第一个解释因子是戈壁和荒漠的干旱、荒漠草原的降水和草原的土壤无机氮。4个生态系统细菌功能类群的地理分布格局与群落组成相似，戈壁和荒漠较干燥的生境中含有可移动元素和革兰氏阴性细菌的类群较多。我们的结果揭示了生物结壳中土壤细菌群落多样性、组成和功能群的非线性变化，表明地理距离和生境特定的环境因素决定了不同生态系统中土壤细菌群落的分布。(C)2020爱思唯尔B.V.保留所有权利。
Biocrusts are common biotic components in diyland ecosystems worldwide, they contain diverse soil organisms and effectively enhance soil stability and perform a series of key ecological functions. However, the geographical pattern of microbial communities in biocrusts is rarely assessed, despite it is closely related to the spatial variation of ecosystem functions in drylands. We assessed soil bacterial communities in biocrusts across four ecosystems (Gobi, desert, desert steppe and grassland) in a precipitation gradient (16-566 mm yr(-1)) in northern China. Bacterial OTU number and phylogenetic diversity did not linearly increase with decreasing aridity, they were significantly lower in Gobi and similar among desert, desert steppe and grassland. Soil bacterial community composition in Gobi and desert were different than those in desert steppe and grassland, and they were similar between Gobi and desert, this suggests the key role of habitat in structuring soil bacterial communities. The geographic pattern of soil bacterial communities was strongly influenced by both geographic distance and environmental factors. The first explanatory factor for the geographic variation of bacterial community dissimilarity differed among four ecosystems, being aridity in Gobi and desert, precipitation in desert steppe, and soil inorganic nitrogen in grassland. The geographic pattern of the bacterial functional group profile showed a similar pattern with community composition across four ecosystems, and the groups of containing mobile elements and gram negative bacteria were more abundant in drier habitats of Gobi and desert. Our results reveal the non-linear changes in diversity, composition and functional group of soil bacterial communities in biocrusts across the precipitation gradient from hyper-arid to semi-humid regions, and suggest that the geographic distance and habitat-specific environmental factors determine the distribution of soil bacterial communities in different ecosystems. (C) 2020 Elsevier B.V. All rights reserved.