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作 者 ：李双江,刘文兆,高桥厚裕,桧山哲哉,福岛义宏,李志,刘志红,张红星

期 刊 ：生态学报 2007年 27卷 5期 页码：1987~1992

关键词：CO2通量；涡度相关法；黄土塬区；日变化；季变化；CO2收支；

Keywords:CO2 flux, eddy covariance method, Loess Plateau, daily variation, variation during each growing stage, CO2 budget,

摘 要 ：利用涡度相关法对黄土塬区小麦地CO₂通量季节变化进行了研究。结果表明：（1）小麦CO₂通量日变化与生育期、光合有效辐射、土壤温度密切相关。（2）小麦各生育期CO2的平均日收支由大到小依次为拔节孕穗期＞返青期＞起身期＞抽穗期＞成熟期＞灌浆期＞出苗分蘖期＞越冬期。（3）白昼CO₂通量与光合有效辐射在出苗分蘖期、起身期、成熟期几乎不相关，在灌浆期低度相关，在其他生育期内都达到了显著相关。CO₂通量与夜间2cm土壤温度在越冬、起身、拔节孕穗期显著相关，其他5个生育期内为低度相关。（4）小麦收割后表现为碳源，各天具体状况与前一天是否降雨、当天的天气状况有关。

Abstract:The seasonal variation of CO₂ flux in a winter wheat field of the Loess Plateau was studied using an eddy covariance method. The following results were obtained. (1) Daily CO₂ flux was closely related to growing stages, photosynthetically active radiation , and soil temperature. (2) The average daily CO₂ flux at different growing stages followed the order of: jointing and booting >reviving >erecting >heading >ripening >grain-filling > seedling and tillering >wintering period. (3) There was little correlation between daytime CO₂ flux and photosynthetically active radiation at the seedling-tillering, heading, and maturing stages; but there was weak correlation during grain filling, and strong correlation in the other stages. There was significant correlation between CO₂ flux and nighttime soil temperatures at the 2-cm depth at the wintering, heading and jointing and booting stage, and low correlation at the other stages. (4) The wheat field became carbon source after harvest. The carbon budget of a given day was affected by the weather of the day as well as the rainfall condition in the previous day.

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