不同林龄尾巨桉人工林土壤呼吸特征及影响因素

Factors Influencing Soil Respiration Characteristics of Eucalyptus urophylla×E.grandis Plantations at Different Ages

为研究不同林龄尾巨桉人工林土壤呼吸速率时间变化特征及其影响因子,通过测定2018年6月—2019年2月时段内4个不同林龄尾巨桉林土壤呼吸速率,分析桉树人工林土壤呼吸速率时间变化及其与影响要素的相关关系。结果表明:4个林分土壤呼吸速率时间变化趋势基本一致,由测定初期逐渐降低,并在2月中下旬开始回升。2、6、10、17年生4个林龄土壤呼吸速率平均值分别为2.51、1.85、4.13、2.56μmol·m^(-2)·s^(-1)。2、6、17年生林分土壤呼吸速率时间变异主要由土壤5 cm处温度变化引起,10年生林分土壤呼吸速率时间变异由土壤温、湿度共同作用。

In order to study the temporal variation and factors influencing soil respiration rate of Eucalyptus urophylla×E.grandis plantations at different ages,the soil respiration rates of E.urophylla×E.grandis plantations of four different ages were measured from June 2018 to February 2019.The temporal variation of soil respiration rate in these plantations and its correlation with various factors were analyzed.The results showed that the temporal variation trend of soil respiration rate of the four plantation stands was basically the same:it decreased gradually from the initial stage of measurement and began to increase in the middle and last ten days of February.The average soil respiration rates of 2,6,10 and 17-year-old plantations were 2.51,1.85,4.13 and 2.56μmol·m^(-2)·s^(-1) respectively.Temporal variations of soil respiration rate in 2,6 and 17-year-old plantations were caused mainly by changes in soil temperatures at 5 cm,and temporal variations of soil respiration rate in the 10-year-old plantation was caused mainly by soil temperature and humidity.