不同林龄橡胶林土壤呼吸速率的变化及其与水热因子的关系

为探明不同林龄橡胶林土壤呼吸速率(Rs)的变化特征及其与水热因子的关系,以云南省景洪市3个不同林龄(2年幼林、7年成林、30年老林)的橡胶林为对象,连续2年,每月定期原位测定地表5 cm土壤呼吸速率(Rs)、土壤温度(Ts)和土壤湿度(Ms)的变化特征.结果表明:3个不同林龄橡胶林的Rs均有显著差异(P<0.05),2...

Comparison of soil respiration rate in rubber plantations at different stand ages and Its relationship with soil hydrothermal factors

In order to explore the changes of soil respiration rate (Rs) and the relationship between Rs and hydrothermal factors in rubber plantations of different ages, rubber plantations at three different stand ages (2 a, 7 a, 30 a) were selected for analysis. The change characteristics of soil respiration rate (Rs), soil temperature (Ts) and soil moisture (Ms) in 5 cm soil surface were measured in situ every month for two years. The results showed that the Rs of rubber plantations at the three stand ages were significantly different (P < 0.05). The Rs of the 2 a rubber plantation (young rubber plantation, YR) was significantly higher than that of the 7 a rubber plantation (mature rubber plantations, MR), and the Rs of the 30 a rubber plantation (old rubber plantation, OR) was the lowest. The Rs, Ts and Ms of the rubber plantations at the three stand ages had obvious seasonal variation, showing significantly higher values in rainy season than in dry season. The peak of soil respiration rate of the rubber plantations at different ages appeared in different months, and the highest Rs values of YR, MR and OR occurred in September, July and June respectively. The Rs had a highly significant positive correlation (P < 0.01) with Ts and Ms in the rubber plantations at different stand ages, the highest with Ms and the lower with Ts. Regression analysis showed that the change characteristics of the Rs in the rubber plantations of different stand ages are the results of combined effect of multiple hydrothermal factors and that Rs is affected mostly by Ms and relatively less by Ts.