School of Life Sciences, Henan University, International Joint Research Laboratory for Global Change Ecology, Kaifeng, Henan 475004, China.
Key Laboratory of Forest Ecology and Environment, China's National Forestry and Grassland Administration, Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, No. 2 Dongxiaofu, Haidian District, Beijing 100091, China.
Sci Total Environ. 2022 Feb 1;806(Pt 4):150957. doi: 10.1016/j.scitotenv.2021.150957. Epub 2021 Oct 14.
Changes in soil microbial community play an irreplaceable role in regulating nutrient cycling that shapes forest ecosystem responses to climate change. However, if the effect of experimental warming on soil microorganisms depends upon soil water availability, which is closely related to soil depth is generally not well decumented. We conducted an in situ simulation experiment in an oak forest to determine the response pattern of soil microbial community to manipulated drought and warming at different soil depths. The responses of soil microbial communities to reduced precipitation and soil warming were highly dependent upon soil depth. Reduced precipitation remarkably elevated top-soil microbial biomass carbon (MBC) and nitrogen (MBN) in the unwarmed plots but no effects occured in the warmed plots. Soil warming showed positive effects on top-soil MBC and MBN under ambient precipitation, whereas negative ones were found under decreased precipitation. Neither reduced precipitation nor soil warming displayed effects on sub-soil MBC and MBN. Reduced precipitation notably increased soil total phospholipid fatty acids (PLFA) as well as that of bacterial and gram-negative bacterial only at top-soil in the unwarmed plots. Soil warming showed positive effects on total PLFA, bacterial PLFA, and gram-negative bacterial PLFA at both top- and sub-soil under ambient precipitation. We found that the interactive effects of climate change on soil microorganisms varied with soil depth, indicating that multilayer soil models should be considered while assessing the relationship between soil and atmosphere carbon exchange. Further research is expected to explore the long-term response of soil microorganisms in soil vertical profiles to climate change.
土壤微生物群落的变化在调节养分循环方面起着不可替代的作用，而养分循环则塑造了森林生态系统对气候变化的响应。然而，如果实验增温对土壤微生物的影响取决于土壤水分的有效性，而土壤水分的有效性通常与土壤深度密切相关，那么这种影响在很大程度上还没有得到很好的记录。我们在一片栎树林中进行了一项原位模拟实验，以确定土壤微生物群落对不同土壤深度下人为干旱和增温的响应模式。土壤微生物群落对减少降水和土壤增温的响应高度依赖于土壤深度。减少降水显著提高了未增温样地的表层土壤微生物生物量碳（MBC）和氮（MBN），但在增温样地中没有这种作用。在自然降水条件下，土壤增温对表层土壤 MBC 和 MBN 表现出积极的影响，而在降水减少的情况下则表现出消极的影响。减少降水或土壤增温对亚表层 MBC 和 MBN 均无影响。减少降水显著增加了土壤总磷脂脂肪酸（PLFA）以及未增温样地中仅在表层土壤中的细菌和革兰氏阴性菌的 PLFA。在自然降水条件下，土壤增温对表层和亚表层土壤的总 PLFA、细菌 PLFA 和革兰氏阴性菌 PLFA 均表现出积极的影响。我们发现，气候变化对土壤微生物的交互影响随土壤深度而变化，这表明在评估土壤与大气碳交换之间的关系时，应该考虑多层土壤模型。进一步的研究预计将探索土壤微生物在土壤垂直剖面中对气候变化的长期响应。
