欢迎访问《草业学报》官方网站,今天是 分享到:

草业学报 ›› 2021, Vol. 30 ›› Issue (9): 27-37.DOI: 10.11686/cyxb2020347

• 研究论文 • 上一篇    下一篇

温度变化对尕海湿地不同退化梯度土壤氮矿化的影响

宋良翠(), 马维伟(), 李广, 刘帅楠, 陆刚   

  1. 甘肃农业大学林学院,甘肃 兰州 730070
  • 收稿日期:2020-07-20 修回日期:2020-09-09 出版日期:2021-08-30 发布日期:2021-08-30
  • 通讯作者: 马维伟
  • 作者简介:Corresponding author. E-mail: maww@gsau.edu.cn
    宋良翠(1993-),女,甘肃兰州人,在读硕士。E-mail: 2365096162@qq.com
  • 基金资助:
    国家自然科学基金项目(31860143);2019陇原青年创新创业(个人项目)(LYRC2019-34);甘肃省财政专项(GSCZZ-20160909);甘肃省重点人才项目(LRYCZ-2020-1)

Effect of temperature changes on nitrogen mineralization in soils with different degradation gradients in Gahai Wetland

Liang-cui SONG(), Wei-wei MA(), Guang LI, Shuai-nan LIU, Gang LU   

  1. College of Forestry,Gansu Agricultural University,Lanzhou 730070,China
  • Received:2020-07-20 Revised:2020-09-09 Online:2021-08-30 Published:2021-08-30
  • Contact: Wei-wei MA

摘要:

氮矿化是土壤中氮素循环的重要过程,研究温度变化对不同退化梯度高寒湿地土壤净氮矿化速率的影响,对于理解全球气候变暖背景下土壤氮循环过程具有重要意义。以甘肃省甘南尕海湿地为研究对象,采用室内培养和间歇淋洗的方法,研究不同温度(15、25、35 ℃)培养下,4种退化梯度湿地(未退化、轻度退化、中度退化及重度退化)的土壤在0~10 cm、10~20 cm、20~40 cm土层的氮矿化特征。结果表明:1)同一湿地退化梯度,土壤净氮矿化速率和硝化速率随温度的升高逐渐增大,氨化速率随温度的升高先增大后减小。一级动力学方程的拟合值显示,35 ℃培养条件下土壤的氮矿化势(N0)最大。在同一温度下,不同退化梯度的土壤氮矿化势值变化显著,因而反映了土壤氮矿化潜力。2)在不同的培养时间下,随着温度的升高,土壤氮矿化速率和硝化速率均呈现上升的趋势;在整个培养期,不同退化梯度湿地的土壤在同一土层中的净氮矿化速率均随着培养时长的延长而呈现下降的趋势,在培养初期(12~24 d),土壤氮矿化速率显著升高,在培养后期,氮矿化速率逐渐减缓。3)湿地不同退化梯度对土壤氮矿化影响差异显著,4种退化程度下土壤净氮矿化量在不同温度下排序为35 ℃>25 ℃>15 ℃。温度对土壤氮矿化过程具有一定影响,高温有利于土壤氮矿化过程的进行。

关键词: 氮矿化, 气候变暖, 尕海湿地

Abstract:

Nitrogen (N) mineralization is a major component in the process of soil N cycling. To further understand soil N cycling in the context of global warming, it is important to explore the effect of temperature variation on soil net nitrogen mineralization rate in alpine Wetland soils with different degradation status. In this research, Gahai Wetland was selected as a model system for study, and a methodology involving indoor incubation of soil samples for 69 days and periodic rinsing was used to study the soil N mineralization characteristics in three soil layers (0-10 cm, 10-20 cm, 20-40 cm) of a four-step soil degradation gradient (non-degraded, mildly-degraded, moderately-degraded and severely-degraded) under the condition of different temperature cultivation. The results indicate that: 1) For the same degeneration level, with increasing temperature, soil net nitrogen mineralization rate and nitrification rate rose, however, ammoniation rate initially increased and then reduced. By fitting the results with a first-order kinetic equation, we found that the maximum value of soil nitrogen mineralization occurred at a culture temperature of 35 ℃. Under the same temperature level, soil nitrogen mineralization potential (N0) showed significant differences depending on the extent of soil degradation, reflecting the potential for soil nitrogen mineralization. 2) Soil nitrogen mineralization and nitrification rates for a particular temperature, soil degradation status, and soil layer decreased with increasing duration of soil culture. Initially rates were high, and over time they slowed. 3) There was a significant difference in soil nitrogen mineralization along the degradation gradients, we ranked the net nitrogen mineralization over the 69 days of incubation for soils with different degradation status and temperature, results were: mineralization at 15 ℃<25 ℃<35 ℃. Our results indicate that temperature has a substantial influence on the process of soil nitrogen mineralization, and high temperature speeds up the process of soil nitrogen mineralization.

Key words: nitrogen mineralization, global warming, Gahai Wetland