Chen Shu-Tao, Sun Lu, Sang Lin, Hu Zheng-Hua
Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology(CICAEET), Nanjing University of Information Science and Technology, Nanjing 210044, China.
School of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, China.
Huan Jing Ke Xue. 2017 Mar 8;38(3):1235-1244. doi: 10.13227/j.hjkx.201608206.
In order to investigate the effects of simulated acid rain on soil respiration and heterotrophic respiration in a secondary forest, a field experiment was carried out. A split-plot experiment was arranged in field. There were 4 blocks; each block had two main plots which were trenched and un-trenched plots. In each main plot, 4 simulated acid rain treatments of control (CK), pH 4.0 (A1), pH 3.0 (A2), and pH 2.0 (A3) were randomly assigned. Soil respiration in the un-trenched plots and heterotrophic respiration in the trenched plots were measured weekly. Soil temperature and moisture at a depth of 5 cm were measured during the respiration measurements. The results indicated that different simulated acid rain treatments exhibited similar seasonal patterns of soil respiration and heterotrophic respiration. Heterotrophic respiration in the trenched plots was significantly lower than soil respiration in the un-trenched plots. The annual mean soil respiration rates for the CK, A1, A2, and A3 treatments in the un-trenched plots were (2.47±0.31), (2.52±0.22), (2.38±0.17), and (2.43±0.22) μmol·(m·s), respectively, while the annual mean heterotrophic respiration rates for the 4 treatments in the trenched plots were (1.55±0.10), (1.65±0.22), (1.77±0.08), and (1.78±0.27) μmol·(m·s), respectively. ANOVA showed that simulated acid rain had no significant effects on soil respiration in the un-trenched plots and heterotrophic respiration in the trenched plots. Regression analysis suggested that there was a significant linear regression relationship between soil respiration and heterotrophic respiration. Simulated acid rain significantly (<0.001) decreased the ratio of soil respiration to heterotrophic respiration. Soil temperature was the main controlling factor regulating the seasonal patterns of soil respiration and heterotrophic respiration for each of the SAR treatment, while soil moisture had no significant effects on the seasonal variability in soil respiration and heterotrophic respiration.
为了研究模拟酸雨对次生林土壤呼吸和异养呼吸的影响，开展了一项田间试验。在田间设置了裂区试验。共有4个区组；每个区组有两个主区，即 trenched 区和未 trenched 区。在每个主区内，随机分配4种模拟酸雨处理，分别为对照（CK）、pH 4.0（A1）、pH 3.0（A2）和pH 2.0（A3）。每周测量未 trenched 区的土壤呼吸和 trenched 区的异养呼吸。在呼吸测量期间，测量5厘米深度处的土壤温度和湿度。结果表明，不同的模拟酸雨处理呈现出相似的土壤呼吸和异养呼吸季节模式。trenched 区的异养呼吸显著低于未 trenched 区的土壤呼吸。未 trenched 区CK、A1、A2和A3处理的年平均土壤呼吸速率分别为(2.47±0.31)、(2.52±0.22)、(2.38±0.17)和(2.43±0.22) μmol·(m·s)，而 trenched 区4种处理的年平均异养呼吸速率分别为(1.55±0.10)、(1.65±0.22)、(1.77±0.08)和(1.78±0.27) μmol·(m·s)。方差分析表明，模拟酸雨对未 trenched 区的土壤呼吸和 trenched 区的异养呼吸没有显著影响。回归分析表明，土壤呼吸和异养呼吸之间存在显著的线性回归关系。模拟酸雨显著（<0.001）降低了土壤呼吸与异养呼吸的比值。土壤温度是调节各模拟酸雨处理土壤呼吸和异养呼吸季节模式的主要控制因素，而土壤湿度对土壤呼吸和异养呼吸的季节变化没有显著影响。
