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2013年7-10月通过对敦煌市南湖乡境内的葡萄种植区有根、无根区域土壤呼吸进行系统观测,分析该地土壤呼吸的时空变化特征及其与温湿度之间的关系.结果表明:葡萄在生长季的各时期土壤呼吸速率的日变化基本为不对称的双峰型曲线,有根区土壤呼吸速率大于无根区的,且二者日变化差异明显,可估算出根呼吸占土壤总呼吸的比例.在日尺度上,0 cm土壤温度与土壤呼吸速率相关性较好,而5 cm土壤温度峰值与土壤呼吸速率峰值之间有位相差,在无根区二者滞后约3 h,有根区滞后时间较小.扩散系数和光合有效辐射显著影响土壤呼吸速率,是迟滞发生的主要原因.土壤温湿度对有根、无根区土壤呼吸的影响有差异.估算葡萄农田土壤呼吸需考虑其距离树干的空间差异性和迟滞现象的影响。
From July to October 2013, the soil respiration of rooted and non-rooted areas in Nanhu township of Dunhuang city was systematically observed, and the temporal and spatial variation of soil respiration and its relationship with temperature and humidity were analyzed. : The diurnal variation of soil respiration rate in grapes during the growing season was basically an asymmetric bimodal curve with the soil respiration rate in the root zone more than that in the non-root zone, and the diurnal variation was significant. The root respiration The ratio of soil total respiration: On the daily scale, the correlation between 0 cm soil temperature and soil respiration rate was good, while the difference between the 5 cm soil temperature peak and the soil respiration rate peak was about 3 h, the root zone lag time is small.Diffusion coefficient and photosynthetically active radiation significantly affect the soil respiration rate, is the main reason for hysteresis.The soil temperature and humidity on rooted and non-root zone soil respiration differences are estimated. Breathing needs to consider the effects of spatial variability and hysteresis on its distance from the trunk.