Wang Dangjun, Zhou Huakun, Zuo Juan, Chen Peng, She Yandi, Yao Buqing, Dong Shikui, Wu Jianshuang, Li Fan, Njoroge Denis Mburu, Shi Guoxi, Mao Xufeng, Ma Li, Zhang Zhonghua, Mao Zhun
Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China.
Key Laboratory of Cold Regions Restoration Ecology, Qinghai Province, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China.
Front Plant Sci. 2022 Apr 8;13:770315. doi: 10.3389/fpls.2022.770315. eCollection 2022.
Climate change and land-use disturbances are supposed to have severely affected the degraded alpine grasslands on the Tibetan Plateau. Artificial grassland establishment has been implemented as a restoration tool against grassland degradation. However, the impact of such degradation and restoration processes on soil microbial communities and soil quality is not clearly understood. Here, we aim to investigate how the dynamics of microbial community and soil quality of alpine grasslands respond to a gradient of degradation and that of restoration, respectively. We conducted a randomised experiment with four degradation stages (light, moderate, heavy, and extreme degradation) and three restoration stages (artificial restoration for 1, 5, and 10 years). We analysed the abundance and diversity of soil bacteria and fungi, and measured soil nutrients, enzymatic activity and microbial biomass. The concentration of soil nitrogen (TN), soil organic matter (OM) in heavy degraded grassland decreased significantly by 37.4 and 45.08% compared with that in light degraded grassland. TN and OM in 10-years restored grassland also increased significantly by 33.10 and 30.42% compared to that in 1-year restored grassland. Four soil enzymatic activity indicators related to microbial biomass decreased with degradation gradient and increased with recovery time (i.e., restoration gradient). Both bacterial and fungal community structure was significantly different among grassland degradation or restoration successional stages. The LEfSe analysis revealed that 29 fungal clades and 9 bacterial clades were susceptible to degraded succession, while16 fungal clades and 5 bacterial clades were susceptible to restoration succession. We conclude that soil quality (TN, OM, and enzymatic activity) deteriorated significantly in heavy degraded alpine grassland. Soil microbial community structure of alpine is profoundly impacted by both degradation and restoration processes, fungal communities are more sensitive to grassland succession than bacterial communities. Artificial grasslands can be used as an effective method of restoring degraded grassland, but the soil functions of artificial grassland, even after 10 years of recovery, cannot be restored to the original state of alpine grassland.
气候变化和土地利用干扰被认为已对青藏高原退化的高寒草原造成了严重影响。人工草地建设已被用作应对草地退化的一种恢复手段。然而，这种退化和恢复过程对土壤微生物群落和土壤质量的影响尚不清楚。在此，我们旨在分别研究高寒草原微生物群落动态和土壤质量如何响应退化梯度和恢复梯度。我们进行了一项随机试验，设置了四个退化阶段（轻度、中度、重度和极度退化）和三个恢复阶段（人工恢复1年、5年和10年）。我们分析了土壤细菌和真菌的丰度和多样性，并测量了土壤养分、酶活性和微生物生物量。与轻度退化草地相比，重度退化草地的土壤氮（TN）浓度和土壤有机质（OM）显著下降了37.4%和45.08%。与1年恢复草地相比，10年恢复草地的TN和OM也显著增加了33.10%和30.42%。与微生物生物量相关的四个土壤酶活性指标随退化梯度降低，随恢复时间（即恢复梯度）增加。草地退化或恢复演替阶段的细菌和真菌群落结构均存在显著差异。线性判别分析效应大小（LEfSe）分析表明，29个真菌分支和9个细菌分支易受退化演替影响，而16个真菌分支和5个细菌分支易受恢复演替影响。我们得出结论，重度退化的高寒草地土壤质量（TN、OM和酶活性）显著恶化。高寒土壤微生物群落结构受到退化和恢复过程的深刻影响，真菌群落比细菌群落对草地演替更敏感。人工草地可作为恢复退化草地的有效方法，但即使经过10年恢复，人工草地的土壤功能仍无法恢复到高寒草地的原始状态。
