Six treatments (control (CK), litter removal (?L), litter addition (+L), root removal (?R), litter and root removal (?R?L), litter addition and root removal (?R+L)) were conducted in a Pinus sylvestris var. mongolica plantation in Saihanba, Hebei Province. Based on the results of the first growing season (May–September 2019) after the treatments, we aimed to evaluate the effects of different plant detritus input on soil respiration and its temperature sensitivity. The results show that: 1) soil respiration rate exhibited significant seasonal dynamics, with peak value in July–August and minimum value in late September. The average soil respiration rates of control, litter removal, litter addition, root removal, litter and root removal, litter addition and root removal treatments were (mean±SE) 2.20±0.17, 1.24±0.09, 2.40±0.07, 2.05±0.11, 1.04±0.07 and 2.28±0.17 μmol/(m²·s) respectively. Compared to the CK, ?L and ?R?L significantly reduced soil respiration rate by 43.6% and 52.7%, respectively; 2) soil respiration in the growing season was significantly and exponentially correlated with soil temperature (p<0.01) among different treatments. The temperature sensitivity of soil respiration (Q₁₀ values) were 2.32±0.13, 2.37±0.05, 2.41±0.09, 2.42±0.14, 2.09±0.08 and 2.87±0.11, respectively. Aboveground litter treatment had significant effects on both average rate and Q₁₀ value of soil respiration (p<0.05), while belowground root treatment did not (p>0.05); 3) compared to CK, soil moisture was significantly higher in all root removal treatments (?R, ?R?L, ?R+L) likely due to the lack of water uptake by roots, but soil temperature did not change significantly. In most treatments (except ?R and ?R+L), soil respiration and soil moisture showed a significant parabolic relationship during the growing season, and the threshold of soil moisture was about 15% (v/v). In conclusion, the results showed that litter removal had significant effects on growing season soil respiration and its temperature sensitivity in the Pinus sylvestris var. mongolica plantation, but root removal had no significant effect in the first growing season after the manipulation.

对河北塞罕坝机械林场樟子松(Pinus sylvestris var. mongolica)人工林采取不同的处理方式(对照(CK)、凋落物移除(-L)、凋落物添加(+L)、根系去除(-R)、凋落物和根系同时去除(-R-L)、凋落物添加和根系去除(-R+L)), 基于处理后第一个生长季(2019年5—9月)的测定结果, 研究不同的植物残体输入方式对土壤呼吸及其温度敏感性的影响, 得到以下结果。1) 土壤呼吸速率存在显著的季节动态, 7—8月最高, 9月底最低。CK, -L, +L, -R, -R-L和-R+L处理组的生长季内平均土壤呼吸速率(平均值±标准误差, 下同)分别为2.20±0.17, 1.24±0.09, 2.40±0.07, 2.05±0.11, 1.04±0.07, 2.28±0.17 μmol/(m²·s), -L和-R-L处理分别使土壤呼吸速率降低43.6%和52.7%。2) 不同处理方式下, 生长季内土壤呼吸与土壤温度显著指数相关(p<0.01), 各处理样地土壤呼吸的温度敏感Q₁₀值分别为2.32±0.13, 2.37±0.05, 2.41±0.09, 2.42±0.14, 2.09±0.08, 2.87±0.11。地上凋落物处理对土壤呼吸生长季平均值和Q₁₀都有显著的影响(p<0.05), 而根系处理对其均无显著影响(p>0.05)。3) 与对照组相比, 在根系去除的处理(-R, -R-L和-R+L)中, 土壤湿度显著升高, 可能与根系停止吸收水分有关, 但土壤温度没有显著的变化。在大部分处理(除-R和-R+L外)中, 生长季内土壤呼吸与土壤湿度呈显著的抛物线式关系, 土壤湿度的阈值为15%左右。综合来看, 凋落物去除对樟子松林土壤呼吸和温度敏感性均产生显著的影响, 而根系去除的影响在第一个生长季不显著。