【摘要】 为掌握华北平原麦田总土壤呼吸、异养呼吸和自养呼吸的日内变化规律及其控制因素,该文于2011年4月—6月开展了土壤呼吸实验,采用根系排除法,测得总土壤呼吸及其2个分量异养呼吸和自养呼吸。结果表明:总土壤呼吸和异养呼吸呈现单峰变化规律,峰值出现在午后14:00附近,自养呼吸无明显日内变化特征。自养呼吸对总土壤呼吸的贡献率在日时间尺度上变化较小,但不同生育期的量值有微小差异。相关关系分析结果表明:异养呼吸与空气温度具有很好相关性,好于与土壤温度的相关性,异养呼吸与空气相对湿度具有较好的负相关性。自养呼吸主要受光合作用速率控制,但在时间上滞后于光合作用速率。因此控制该地区麦田土壤呼吸日内变化的主要因素为空气温度、空气湿度和光合作用速率。更多还原

【Abstract】 Soil respiration in a typical wheat cropland was measured from April to June,2011 to understand the diel variations of the total soil respiration, heterotrophic respiration, autotrophic respiration,and their corresponding controlling factors in wheat croplands in the North China Plain.The root exclusion method was used to measure total soil respiration,heterotrophic respiration and autotrophic respiration.The results showed that the total soil respiration and the heterotrophic respiration both had single peaks at around 14:00, while the autotrophic respiration did not have apparent diel characteristics.The ratio of autotrophic respiration to the total soil respiration varied little throughout the day but varied some during different growth stages.The heterotrophic respiration was more closely related to the air temperature than to the soil temperature. In addition, the heterotrophic respiration was negatively correlated to the relative humidity. The autotrophic respiration was dependent on the gross primary production with a time lag.In summary,the diel variations of soil respiration in a field were mainly dependent on the air temperature,relative humidity and photosynthesis rate.更多还原