松嫩平原典型黑土分布区土壤呼吸研究

A study of soil respiration of typical black soil in Songnen Plain,northeastern China

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。

We measured soil respiration in different land uses, such as crop land, fallow land and uncultivated land, located in typical black soil area of Songnen Plain. Autotrophic and heterotrophic soil respiration was distinguished by trenching. Temperature sensitivity of soil respiration （Q10） was calculated in different land use respectively. The results indicated that soil respiration was controlled by many factors, such as soil temperature, soil moisture, vegetation types and cultivation activities. Diurnal soil respiration was dominated by temperature. Autotrophie respiration by plant root occupies 50% of the soilrespiration in summer, but the ratio in spring and autumn is less than that in summer. Because of different vegetation types and different proportion of autotrophic soil respiration occupied, autotrophic soil respiration in different land use decreases in order of uncultivated land 〉 fallow land〉-erop land. Q10 of soil respiration with plants is bigger than those without plants.