水土保持措施对板栗林土壤呼吸的影响

为阐明板栗林土壤呼吸对水土保持措施的响应,采用IRGA法,对不同类型板栗林的土壤呼吸从2009年3月至2010年9月开展为期1年半的定位观测。结果表明:1)采取水土保持措施后,样地的土壤水分状况得到一定程度的改善,尤其随着采取水土保持措施年限的延长,其对土壤水分时空分布影响更为显著。2)4个板栗林样地的土壤呼吸速率均呈明显的单峰曲线变化,水土保持措施对土壤呼吸的季节动态无明显影响。3)样地Ⅰ和Ⅲ的参考呼吸R10分别为1.718和1.595μmol/(m2.s);而采取水土保持措施后,样地Ⅱ和Ⅳ的R10均表现为一定程度的降低,分别为1.092和1.324μmol/(m2.s)。样地Ⅰ和Ⅲ的土壤呼吸的温度敏感性指数Q10分别为1.927和1.899;采取水土保持措施后,样地Ⅱ和Ⅳ的Q10均表现为略微增加。采取水土保持措施后,土壤温度和土壤湿度对土壤呼吸速率的影响有一定程度的增强。研究结果可为把水土保持措施作为土壤严重侵蚀地区一种潜在的固碳减排模式提供基础数据。

Response of soil respiration to soil and water conservation measures in Castanea mollissima plantations

In order to ascertain the response of soil respiration to soil and water conservation measures, soil respiration rates of four Castanea mollissima plantations in the HenTian Town were measured with an infrared gas analyzing method by using an open-flow gas exchange system from March 2009 to September 2010. The results show that： 1） soil water content was improved to some extent after implementing soil and water conservation measures, especially with the prolonged years of application, the temporal and spatial of soil water contents was significantly improved. 2 ） Soil respiration rates of four Castanea mollissima plantations changed as an one-humped curve, There was no obvious effect of soil and water conservation measures on the seasonal patterns of soil respiration. 3）The reference respiration R~o values in the plot I and Ⅲ were 1. 718 and 1. 595 μmol/（m^2. s） , respectively; with soil and water conservation measures in the plot Ⅱ and IV R10 values decreased to 1. 092 and 1. 324 ~mol/（m^2. s）, after implementing measures. The temperature sensitivity index Ql0 values in the plot I and Ⅲ were 1. 927 and 1. 899; after implementing measures, for the same reason in the plot Ⅱ and Ⅳ Q10 values slightly increased to some extent after implementing soil and water conservation measures, which could influence of soil temperature and soil moisture to some extent. The study provided base data to consider soil and water conservation measures as a potential mode of fixing carbon and reducing emission in soil severely eroded areas.