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在松嫩平原典型黑土分布区,选择耕地、休耕地、自然荒地3种土地利用方式进行土壤CO2呼吸研究。采用壕沟隔断法,探讨了植物根系呼吸在不同土地利用方式下的差异,采用温度敏感系数Q10分析了不同土地利用方式下土壤呼吸对温度的敏感性。结果表明:土壤呼吸受多方面因素影响,包括土壤温度、湿度、植被类型、农业生产活动等。土壤呼吸日变化过程中,温度是影响土壤呼吸速率的决定性因素。在夏季植物根系呼吸所占的比例最大,超过了50%,春秋两季根系呼吸所占的比例相对较少。受植物种类及植物根系呼吸在土壤呼吸中所占比例大小的影响,在3种不同的土地利用方式下根系自养呼吸所占的比例大小顺序依次为荒地>休耕地>耕地。有根系的土壤呼吸对土壤温度升高的反应要敏感些。
In the typical black soil area of Songnen Plain, soil CO2 respiration was selected from three land use types: arable land, fallow land and natural wasteland. Using the method of moat partition, the differences of plant root respiration under different land use patterns were discussed. The temperature sensitivity coefficient Q10 was used to analyze the sensitivity of soil respiration to temperature under different land use patterns. The results show that soil respiration is affected by many factors, including soil temperature, humidity, vegetation types and agricultural production activities. During the diurnal variation of soil respiration, temperature is the decisive factor affecting soil respiration rate. In summer, the largest proportion of plant root respiration, more than 50%, spring and autumn root respiration accounted for a relatively small proportion. Affected by plant species and the proportion of plant root respiration in soil respiration, the proportion of autotrophic respiration in the three different land use patterns was in order of barren land> fallow land> farmland. Rooted soil respiration is more sensitive to soil temperature.