植物生态学报 ›› 2024, Vol. 48 ›› Issue (4): 523-533.DOI: 10.17521/cjpe.2022.0346

• 研究论文 • 上一篇    下一篇

不同类型草原土壤净氮矿化速率的温度敏感性

王袼1,*, 胡姝娅2, 李阳2, 陈晓鹏1, 李红玉1, 董宽虎1, 何念鹏3, 王常慧1,2,**   

  1. 1山西农业大学草业学院, 草地生态保护与乡土草种质创新山西省重点实验室, 山西太谷 030801
    2中国科学院植物研究所植被与环境变化国家重点实验室, 北京 100093
    3中国科学院地理科学与资源研究所生态系统网络观测与模拟重点实验室, 北京 100101
  • 收稿日期:2022-08-25 接受日期:2023-02-20 出版日期:2024-04-20 发布日期:2024-05-11
  • 通讯作者: **
  • 作者简介:wg18335963261@163.com
  • 基金资助:
    中国科学院战略性先导科技专项(A类)(XDA23080402);国家重点研发计划(2017YFA0604802);第二次青藏高原综合科学考察研究项目(2019QZKK0606);山西省重点实验室项目(202104010910017)

Temperature sensitivity of soil net nitrogen mineralization rates across different grassland types

WANG Ge1,*, HU Shu-Ya2, LI Yang2, CHEN Xiao-Peng1, LI Hong-Yu1, DONG Kuan-Hu1, HE Nian-Peng3, WANG Chang-Hui1,2,**   

  1. 1College of Grassland Science, Shanxi Agricultural University, Shanxi Key Laboratory of Grassland Ecological Protection and Native Grass Germplasm Innovation, Taigu, Shanxi 030801, China
    2State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
    3Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
  • Received:2022-08-25 Accepted:2023-02-20 Online:2024-04-20 Published:2024-05-11
  • Contact: **
  • Supported by:
    Strategic Priority Research Program of the Chinese Academy of Sciences(XDA23080402);National Key R&D Program of China(2017YFA0604802);Second Tibetan Plateau Scientific Expedition and Research (STEP) Program(2019QZKK0606);Key Laboratory Program of Shanxi Province(202104010910017)

摘要:

土壤中的无机氮是维持陆地生态系统生产力的主要限制因子, 主要通过有机氮的矿化产生。土壤氮可利用性的高低取决于土壤微生物、地上植被类型以及土壤理化性质等。土壤微生物对环境变化极为敏感, 尤其是温度与微生物生长繁殖密切相关。因此, 在较大空间范围内研究微生物调控氮矿化速率的温度敏感性(Q10)对于预测全球气候变化对陆地生态系统生产力的影响至关重要。该研究以中国三大高原(内蒙古高原、黄土高原和青藏高原)的不同类型草原为研究对象, 通过野外采集土壤样品, 室内不同温度培养测定三大高原不同类型草地土壤的净氮矿化速率, 计算其Q10, 并分析其与土壤微生物及土壤理化性质参数的相关性。结果表明: (1)黄土高原不同类型草地土壤氮矿化速率的Q10显著高于内蒙古高原和青藏高原; (2)在黄土高原和内蒙古高原, 草甸草原和典型草原土壤净氮矿化速率的Q10显著高于荒漠草原, 而青藏高原高寒草甸草原土壤净氮矿化速率的Q10显著低于高寒典型草原和高寒荒漠草原; (3)三大高原草地土壤微生物生物量碳含量与土壤净氮矿化速率的Q10显著相关; (4) Q10的空间格局受微生物、土壤质地以及底物的共同调控。该研究结果为中国不同类型草原土壤氮循环对全球变化响应的研究提供了重要数据, 对于陆地生态系统氮循环模型的完善具有一定的科学价值。

关键词: 氨氧化微生物, 微生物生物量碳, 微生物生物量氮, 净氮矿化速率, 温度敏感性(Q10)

Abstract:

Aims Soil available nitrogen (N), generated from a series of soil mineralization processes, is a major limiting factor of terrestrial ecosystem productivity. Soil N availability depends on soil microorganisms, vegetation types, and soil physical and chemical properties. Soil microorganisms are very sensitive to environmental changes, especially the temperature change, which is closely related with microbial growth and reproduction. Therefore, it is important to understand the temperature sensitivity (Q10) of microbial regulation of N mineralization rates in a large spatial scale for predicting the impacts of global climate changes on terrestrial ecosystem productivity.
Methods Three types of grasslands (namely meadow steppe, typical steppe, and desert steppe) were selected in Nei Mongol Plateau, Loess Plateau, and Qingzang Plateau, respectively. Soil net N mineralization rates were measured at different temperatures in the laboratory, and then Q10 of N mineralization rates were calculated across different grassland types. Relative parameters, including soil microbe, soil physical and chemical properties, were also analyzed.
Important findings (1) The highest Q10 of soil net N mineralization rates was found in all of three grassland types of Loess Plateau than those of Nei Mongol and Qingzang Plateaus. (2) The Q10 values of soil net N mineralization rates in the meadow steppes and typical steppes on the Loess Plateau and Nei Mongol Plateau were significantly higher than those in the desert steppes, while on the Qingzang Plateau, the values in the alpine meadow steppes were significantly lower than that in the alpine typical steppes and alpine desert steppes. (3) Q10 values of soil net N mineralization rates was closely correlated with soil microbial biomass carbon content across different grassland types. (4) The spatial pattern of Q10 is jointly regulated by microorganisms, soil texture and substrate. The results of this study provide important data for understanding of the response of soil N cycle to global change in different grassland types in China, which is valuable for optimization of N cycle models of terrestrial ecosystems in the future.

Key words: ammonia-oxidizing microorganisms, microbial biomass carbon, microbial biomass nitrogen, net nitrogen mineralization rate, temperature sensitivity (Q10)