Gansu Agricultural University/Key Laboratory of Grassland Ecosystem of the Ministry of Education, College of Grassland Science, Lanzhou, China.
PLoS One. 2022 Jul 14;17(7):e0271399. doi: 10.1371/journal.pone.0271399. eCollection 2022.
This research was designed to explore the variation characteristics of soil C:N:P stoichiometry and enzyme activity in the Qilian Mountains different grassland types. Thus, 7 grassland types (Upland meadow: UM, Alpine meadow: AM, Temperate steppe: ST, Alpine steppe: AS, Temperate Desert Steppe: TDS, Temperate Desert: TD, Alpine desert: AD) of Qilian Natural Reserve were selected to analyze the variation characteristics of soil enzyme activities and stoichiometry of different grassland types and its relationship with environmental factors. The study indicated that the C/N, C/P, and N/P of different grasslands ranged from 5.08 to 17.35, 2.50 to 72.29, and 0.53 to 4.02.The ranking of different types grassland for the C/N was TS ≥ AM ≥ UM ≥ AS ≥ TDS > AD > TD, and the changing pattern of C/P and N/P is similar to that of C/N. The ranking of different types grassland for the urease enzyme activity was UM ≈AS > AD ≈TDS ≈TS ≈AM > TD, and TS ≈AM ≈UM ≈AS ≈AD > TDS > TD for alkaline phosphatase enzyme activity, and AS ≈AM ≈TS ≈TDS≥UM ≥TD ≈AD for catalase enzyme activity. Based on N/P ratio and RDA analysis, nitrogen was the main factor limiting the grassland productivity, and pH, TN, SOC, Richness index and Simpson diversity index were the main environmental factors affecting the soil C:N:P stoichiometry and enzyme activities. Cluster analysis showed that 7 grassland types were clustered into three categories. In conclusion, the stoichiometric characteristics and soil enzyme activities of different grasslands vary with grassland types. Nitrogen was the main factor limiting the grasslands productivity, and pH, TN, SOC, Richness index and Simpson diversity index were the main environmental factors affecting the soil C:N:P stoichiometry and enzyme activities, and the grassland Qilian Mountain can be managed in the ecological district according to the clustering results. The results of this study can provide data support and theoretical guidance for the scientific management and ecological protection of grassland in Qilian Mountains Reserve.
本研究旨在探索祁连山不同草地类型土壤 C:N:P 化学计量和酶活性的变化特征。因此，选择祁连自然保护区的 7 种草地类型（高山草甸：UM，高山草甸：AM，温带草原：ST，高山草原：AS，温带荒漠草原：TDS，温带荒漠：TD，高山荒漠：AD）来分析不同草地类型土壤酶活性和化学计量的变化特征及其与环境因子的关系。研究表明，不同草地的 C/N、C/P 和 N/P 范围分别为 5.08-17.35、2.50-72.29 和 0.53-4.02。不同类型草地的 C/N 排序为 TS≥AM≥UM≥AS≥TDS>AD>TD，C/P 和 N/P 的变化模式与 C/N 相似。不同类型草地的脲酶活性排序为 UM≈AS>AD≈TDS≈TS≈AM>TD，碱性磷酸酶活性排序为 TS≈AM≈UM≈AS≈AD>TDS>TD，而过氧化氢酶活性排序为 AS≈AM≈TS≈TDS≥UM≥TD≈AD。基于 N/P 比和 RDA 分析，氮是限制草地生产力的主要因素，而 pH、TN、SOC、丰富度指数和 Simpson 多样性指数是影响土壤 C:N:P 化学计量和酶活性的主要环境因素。聚类分析表明，7 种草地类型可分为 3 类。总之，不同草地的化学计量特征和土壤酶活性随草地类型而异。氮是限制草地生产力的主要因素，而 pH、TN、SOC、丰富度指数和 Simpson 多样性指数是影响土壤 C:N:P 化学计量和酶活性的主要环境因素，根据聚类结果，可以对祁连山草地进行生态分区管理。本研究结果可为祁连山保护区草地的科学管理和生态保护提供数据支持和理论指导。
