关键词: 采伐剩余物管理, 土壤呼吸, 温度, 湿度, 土壤可溶性有机碳

Abstract: We measured monthly soil respiration (R_s) in a 15 year-old replanted Chinese fir plantation which was located in subtropical China and subjected to five harvest residue management treatments. The treatments included: whole tree harvest plus forest floor removal, whole tree harvest,stem only harvest, double the residue, and burning the residue. Repeated measures ANOVA showed that harvest residue management had little effects on R_s rate, soil temperature and soil moisture in the whole year or four different seasons. Soil respiration displayed obvious seasonal dynamics, with the maximum happening in June 2012 (3.09 μmol CO₂·m^-2s^-1, averaged from five treatments) and the minimum happing in February 2012 (0.69 μmol CO₂·m^-2s^-1). Soil temperature was found to be the most important factor controlling the temporal pattern of soil respiration, accounting for 55.8%-72.6% of variations in R_s rate. There were no significant differences in temperature sensitivity of R_s (Q₁₀) and annual soil CO₂ emission among treatments, and the mean values of five treatments were 2.14 and 701.17 gC·m^-2, for Q₁₀ and annual soil CO₂ emission. Harvest residue treatment had no significant effects on dissolved organic carbon (DOC) concentrations (0-10 cm depth) extracted by water, hot water or 2 mol·L^-1 KCl. DOC concentrations extracted by water and 2 mol·L^-1 KCl were correlated positively with annual R_s rate and the R_s rate in the given month when soil samples were collected, respectively.

Key words: harvest residue management, soil respiration, temperature, moisture, soil dissolved organic carbon