Shao Ming, Zhang Shengyin, Pei Yu, Song Sen, Lei Tianzhu, Yun Hanbo
Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, China.
University of Chinese Academy of Sciences, Beijing, China.
Front Microbiol. 2023 Mar 21;14:1125832. doi: 10.3389/fmicb.2023.1125832. eCollection 2023.
Under climate warming conditions, storage and conversion of soil inorganic carbon () play an important role in regulating soil carbon (C) dynamics and atmospheric CO content in arid and semi-arid areas. Carbonate formation in alkaline soil can fix a large amount of C in the form of inorganic C, resulting in soil C sink and potentially slowing global warming trends. Therefore, understanding the driving factors affecting carbonate mineral formation can help better predict future climate change. Till date, most studies have focused on abiotic drivers (climate and soil), whereas a few examined the effects of biotic drivers on carbonate formation and stock. In this study, , calcite content, and soil microbial communities were analyzed in three soil layers (0-5 cm, 20-30 cm, and 50-60 cm) on the Beiluhe Basin of Tibetan Plateau. Results revealed that in arid and semi-arid areas, and soil calcite content did not exhibit significant differences among the three soil layers; however, the main factors affecting the calcite content in different soil layers are different. In the topsoil (0-5 cm), the most important predictor of calcite content was soil water content. In the subsoil layers 20-30 cm and 50-60 cm, the ratio of bacterial biomass to fungal biomass (B/F) and soil silt content, respectively, had larger contributions to the variation of calcite content than the other factors. Plagioclase provided a site for microbial colonization, whereas Ca contributed in bacteria-mediated calcite formation. This study aims to highlight the importance of soil microorganisms in managing soil calcite content and reveals preliminary results on bacteria-mediated conversion of organic to inorganic C.
在气候变暖条件下，土壤无机碳（）的储存与转化在干旱和半干旱地区调节土壤碳（C）动态及大气CO含量方面发挥着重要作用。碱性土壤中碳酸盐的形成能够以无机碳的形式固定大量碳，导致土壤碳汇，并可能减缓全球变暖趋势。因此，了解影响碳酸盐矿物形成的驱动因素有助于更好地预测未来气候变化。迄今为止，大多数研究聚焦于非生物驱动因素（气候和土壤），而少数研究考察了生物驱动因素对碳酸盐形成和储量的影响。在本研究中，对青藏高原北麓河盆地三个土壤层（0 - 5厘米、20 - 30厘米和50 - 60厘米）的 、方解石含量和土壤微生物群落进行了分析。结果表明，在干旱和半干旱地区，三个土壤层之间的 和土壤方解石含量未表现出显著差异；然而，影响不同土壤层中方解石含量的主要因素有所不同。在表层土壤（0 - 5厘米）中，方解石含量最重要的预测指标是土壤含水量。在20 - 30厘米和50 - 60厘米的下层土壤中，细菌生物量与真菌生物量之比（B/F）和土壤粉砂含量分别对方解石含量变化的贡献大于其他因素。斜长石为微生物定殖提供了场所，而钙在细菌介导的方解石形成过程中发挥作用。本研究旨在强调土壤微生物在控制土壤方解石含量方面的重要性，并揭示细菌介导有机碳向无机碳转化的初步结果。
