Acta Agrestia Sinica

›› 2007, Vol. 15 ›› Issue (1): 20-28.DOI: 10.11733/j.issn.1007-0435.2007.01.004

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Mineralization of Soil Organic Carbon and Its Motivating Factors to the Dragon Spruce Forest and Alpine Meadows of the Qilian Mountains

WU Jian-guo1, AI Li1,2, ZHU Gao3, TIAN Zi-qiang1, CHANG Wei1,4   

  1. 1. Chinese Academy of Environmental Sciences, Beijing 100012, China;
    2. Beijing Science and Technology University, Beijing 100083, China;
    3. Xishui Conservation Station of the Qilian Mountains Natural Reserve, Zhangye, Gansu Province 734000, China;
    4. Beijing Forestry University, Beijing 100083, China
  • Received:2006-09-11 Revised:2006-11-30 Online:2007-02-15 Published:2007-02-15

祁连山北坡云杉林和草甸土壤有机碳矿化及其影响因素

吴建国1, 艾丽1,2, 朱高3, 田自强1, 苌伟1,4   

  1. 1. 中国环境科学研究院, 北京, 100012;
    2. 北京科技大学, 北京, 100083;
    3. 甘肃祁连山保护局西水保护站, 甘肃, 张掖, 7340004;
    4. 北京林业大学, 北京, 100083
  • 作者简介:吴建国(1971- ),男,副研究员,主要研究土壤氮循环和气候变化影响,E-mail:wujg@craes.org.cn
  • 基金资助:
    国家自然科学基金项目(40543014)资助

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Abstract: To understand the effects of varying soil temperature and changing water content on the decomposition of soil organic carbon(SOC),an anaerobic incubation experiment with orthogonal experiment in an artificial climatic chamber was conducted.The test of significance of difference and the first order kinetic model were used to investigate how mineralization of soil organic carbon of the slopes under the Qilian Mountains forest(dominated by Picea crassifolia) and alpine meadows was affected by the alpine temperature,soil water content,soil depth,and mountain altitudes.The results show that the effects of varying soil temperature on the cumulative SOC mineralization and mineralization rate and their ratio were the highest;next were the effects of the changing soil water content.At 1% critical level,the cumulative SOC mineralization, mineralization rate,and their ratios were the highest at 35℃.At 5% critical level,the SOC mineralization,mineralization rate,and their ratios in soil water content of 10% were the lowest;there was no significant difference among the different altitudes.At 10% critical level,the SOC mineralization was higher in 0~15 cm soil depth than in 15~35 cm soil depth,and the difference of the mineralization ratio was not significant among different soil depths.SOC mineralization potential increased with the rising soil temperature and declined to the lowest when the soil water content fell to(10%).(The)(rate)(constant)(of)(SOC)(mineralization)(was)(the)(highest)(in)(35℃)((P<0.05)).(Based)(on)(the)(rate)(of) SOC mineralization or its ratio,Q10 was 1.5~7.5 from 5℃ to 15℃,1~2 from 15℃ to 25℃,and 1~3 from 25℃ to 35℃.The study indicates that the mineralization rate of SOC under mountain forest and alpine meadows in the Qilian Mountains would increase by 3~10 times if soil water content reached 20%~40% following the changing of temperature from 5℃ to 35℃.

Key words: Qilian mountains, Mineralization of soil organic carbon, Temperature, Soil water content, Mountain forest, Alpine meadows, Altitude

摘要： 为确定祁连山典型生态系统土壤有机碳分解对水热因素变化的响应趋势,在人工气候箱内以正交试验好气培养土壤,应用差异性检验和一阶动态方程方法分析了祁连山青海云杉(Picea crassifolia)林和高寒草甸土壤有机碳矿化及其与温度、湿度、土层和海拔的关系。结果显示:温度对土壤有机碳矿化量、矿化速率及其比例的影响最大,其次是土壤湿度;这些变量在35℃下最高(P<0.01),土壤含水量为10%时最低,不同海拔间差异不显著;土壤有机碳矿化量在0~15cm比15~35cm土层高,但矿化比例差异不显著;土壤有机碳矿化势随温度的升高而增加,土壤含水量为10%时较低,矿化速率系数在35℃下最高(P<0.05);从05℃升到15℃,Q10为1.5~7.5,15℃升到25℃,为1~2,25℃升到35℃,为1.5~3.5。结果说明温度从5℃升高到35℃,土壤含水量在20%~40%,祁连山中部山地森林和高寒草甸土壤有机碳矿化速率将可能增加3~10倍以上。

关键词: 祁连山, 土壤有机碳矿化, 温度, 土壤含水量, 山地森林, 高寒草甸, 海拔高度

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