Fu Fangwei, Li Jiangrong, Li Yueyao, Chen Wensheng, Ding Huihui, Xiao Siying
Research Institute of Tibet Plateau Ecology, Tibet Agriculture and Animal Husbandry University, Nyingchi, Tibet, China.
Key Laboratory of Forest Ecology in Tibet Plateau, Ministry of Education, Nyingchi, Tibet, China.
Front Microbiol. 2023 Jun 2;14:1189859. doi: 10.3389/fmicb.2023.1189859. eCollection 2023.
Qinghai-Tibet Plateau is considered a region vulnerable to the effects of climate change. Studying the effects of climate change on the structure and function of soil microbial communities will provide insight into the carbon cycle under climate change. However, to date, changes in the successional dynamics and stability of microbial communities under the combined effects of climate change (warming or cooling) remain unknown, which limits our ability to predict the consequences of future climate change. In this study, soil columns of an var. forest at 4,300 and 3,500 m elevation in the Sygera Mountains were incubated in pairs for 1 year using the PVC tube method to simulate climate warming and cooling, corresponding to a temperature change of ±4.7°C. Illumina HiSeq sequencing was applied to study alterations in soil bacterial and fungal communities of different soil layers. Results showed that warming did not significantly affect the fungal and bacterial diversity of the 0-10 cm soil layer, but the fungal and bacterial diversity of the 20-30 cm soil layer increased significantly after warming. Warming changed the structure of fungal and bacterial communities in all soil layers (0-10 cm, 10-20 cm, and 20-30 cm), and the effect increased with the increase of soil layers. Cooling had almost no significant effect on fungal and bacterial diversity in all soil layers. Cooling changed the structure of fungal communities in all soil layers, but it showed no significant effect on the structure of bacterial communities in all soil layers because fungi are more adapted than bacteria to environments with high soil water content (SWC) and low temperatures. Redundancy analysis (RDA) and hierarchical analysis showed that changes in soil bacterial community structure were primarily related to soil physical and chemical properties, whereas changes in soil fungal community structure primarily affected SWC and soil temperature (Soil Temp). The specialization ratio of fungi and bacteria increased with soil depth, and fungi were significantly higher than bacteria, indicating that climate change has a greater impact on microorganisms in deeper soil layers, and fungi are more sensitive to climate change. Furthermore, a warmer climate could create more ecological niches for microbial species to coexist and increase the strength of microbial interactions, whereas a cooler climate could have the opposite effect. However, we found differences in the intensity of microbial interactions in response to climate change in different soil layers. This study provides new insights to understand and predict future effects of climate change on soil microbes in alpine forest ecosystems.
青藏高原被认为是一个易受气候变化影响的地区。研究气候变化对土壤微生物群落结构和功能的影响，将有助于深入了解气候变化下的碳循环。然而，迄今为止，在气候变化（变暖或变冷）的综合影响下，微生物群落演替动态和稳定性的变化仍然未知，这限制了我们预测未来气候变化后果的能力。在本研究中，利用PVC管法对色季拉山海拔4300米和3500米处的川西云杉林土壤柱进行配对培养1年，以模拟气候变暖和变冷，相应的温度变化为±4.7°C。应用Illumina HiSeq测序技术研究不同土层土壤细菌和真菌群落的变化。结果表明，变暖对0-10厘米土层的真菌和细菌多样性没有显著影响，但变暖后20-30厘米土层的真菌和细菌多样性显著增加。变暖改变了所有土层（0-10厘米、10-20厘米和20-30厘米）的真菌和细菌群落结构，且这种影响随着土层深度的增加而增大。变冷对所有土层的真菌和细菌多样性几乎没有显著影响。变冷改变了所有土层的真菌群落结构，但对所有土层的细菌群落结构没有显著影响，因为真菌比细菌更能适应高土壤含水量（SWC）和低温的环境。冗余分析（RDA）和层次分析表明，土壤细菌群落结构的变化主要与土壤理化性质有关，而土壤真菌群落结构的变化主要受SWC和土壤温度（Soil Temp）的影响。真菌和细菌的专业化比率随土壤深度增加而增加，且真菌显著高于细菌，表明气候变化对深层土壤中的微生物影响更大，且真菌对气候变化更敏感。此外，气候变暖可以为微生物物种共存创造更多的生态位，并增强微生物相互作用的强度，而气候变冷则可能产生相反的效果。然而，我们发现不同土层中微生物相互作用对气候变化的响应强度存在差异。本研究为理解和预测气候变化对高山森林生态系统土壤微生物的未来影响提供了新的见解。
