快速城市化极大地改变了土壤环境,生物多样性,和陆地生态系统的稳定性。土壤微生物群落,全球生物多样性的关键组成部分,在生态系统稳定中起着举足轻重的作用,并且极易受到城市化的影响。然而,城市化对多样性的影响,稳定性,土壤微生物群落的网络结构仍然知之甚少。在这里,研究了土壤微生物群落的多样性和稳定性,包括细菌,真菌,和原生生物,跨越三个城市化水平不同的地区——城市,郊区,和生态区-使用高通量测序技术。我们的结果表明,城市化导致土壤微生物群落的α多样性显着下降,导致土壤稳定性显著下降,通过平均变异度(AVD)评估。稳定性的丧失与土壤真菌和protistan群落的α多样性减少有关,随着细菌之间相互作用的减弱,真菌,和原生生物。值得注意的是,通过网络分析鉴定的大多数梯形物种被归类为细菌(变形杆菌),并与影响AVD的环境因素呈强正相关。这突出表明,细菌的变异性以及真菌和原生生物的不变性对于维持土壤微生物的稳定性至关重要。此外,结构方程模型表明,protistan多样性主要驱动所有研究区域的土壤微生物稳定性。在郊区和生态区,土壤微生物稳定性直接受土壤性质的影响,细菌多样性,和基石物种,以及间接受重金属影响。这些结果强调了城市化如何通过降低多样性和网络复杂性来降低土壤微生物群落的稳定性。而生态区的建立可能有助于保持土壤微生物群落的多样性和稳定性。
Rapid
urbanization considerably alters soil environment, biodiversity, and stability of terrestrial ecosystems. Soil microbial community, a key component of global biodiversity, plays a pivotal role in ecosystem stability and is highly vulnerable to
urbanization. However, effects of
urbanization on the diversity, stability, and network structure of soil microbial community remain poorly understood. Herein, we investigated the diversity and stability of soil microbial communities, including bacteria, fungi, and protists, across three regions with different levels of urbanization-urban, suburb, and ecoregion-using high-throughput sequencing techniques. Our results revealed that
urbanization led to a notable decrease in the alpha diversity of soil microbial community, causing a significant reduction in soil stability, as assessed by the average variation degree (AVD). The loss of stability was linked to the diminished alpha diversity of the soil fungal and protistan communities, along with weakened interactions among bacteria, fungi, and protists. Notably, the majority of keystone species identified through network analysis were classified as bacteria (Proteobacteria) and displayed a strong positive correlation with the environmental factors influencing AVD. This highlights that the variability of bacteria and the immutability of fungi and protists are important to sustain soil microbial stability. Furthermore, structural equation models indicated that protistan diversity primarily drove soil microbial stability across all regions studied. In the suburban and ecoregion areas, soil microbial stability was directly influenced by the soil properties, bacterial diversity, and keystone species, as well as indirectly affected by heavy metals. These results underscore how
urbanization can reduce the stability of soil microbial community via declined diversity and network complexity, whereas the establishment of ecoregions maybe contribute to preserve the diversity and stability of soil microbial community.