中文摘要：

【目的】研究凋落物对米槠天然林和人工林土壤呼吸的影响,为未来气候变化条件下评估森林土壤CO2排放提供科学依据。【方法】以福建省三明市格氏栲自然保护区内林龄约200年的米槠天然林和林龄50余年的米槠人工林为对象,在每种林分内设置3块20 m×20 m样地,每块样地内随机布设9个1 m×1 m的试验小区,设置对照（CK）,枯落物、凋落物去除（no Litter,NL）和枯落物保留、凋落物加倍（double litter,DL）3种处理。于2013年1月至2014年12月,每月月中及月末在9：00—12：00采用LI-8100A测定不同处理的土壤呼吸,并测定5 cm土深土壤温度及0-10 cm土层土壤体积含水率。【结果】研究期内NL、DL、CT处理的土壤温度在米槠天然林分别为18.2,18.0和17.98℃,在米槠人工林分别为18.68,18.70和18.76℃,均无显著差异,但人工林土壤温度显著高于天然林;凋落物对土壤呼吸的贡献率在米槠天然林中为11.8%,在米槠人工林中为29.7%;米槠天然林DL处理比CK处理土壤呼吸年通量增加了25.2%（P〈0.05）,表现出激发效应,而米槠人工林DL处理土壤呼吸年通量与CK无显著差异;2种林分土壤呼吸速率与5 cm土深土壤温度均呈极显著的指数关系（P〈0.001）,与0-10 cm土层土壤体积含水量均显著正相关（P〈0.05）。【结论】凋落物添加对米槠天然林土壤呼吸产生激发效应,而对人工林土壤呼吸无显著影响。

英文摘要：

【Objective】We investigated the effects of litter manipulation on soil respiration in Castanopsis carlesii forest and C. carlesii plantation to provide a scientific basis for an estimate of carbon dioxide emission in forest soil for the global climate change in the future.【Method】Our experimental sites are located at the C. kawakamii Nature Reserve,Sanming,Fujian,China,where a C. carlesii forest（less man-made interference in recent 200 years） and a C. carlesii plantation（planted 50 years ago） were selected. We set 3 plots（20 m × 20 m） in each forest. And each plot was set 9 subplots（1 m × 1 m）. A litter manipulation experiment（No Litter,NL; Double Litter,DL and Control,CK） was carried out in these subplots. Soil respiration was measured using a soil carbon flux system（LI-8100A） during the period from January2013 to December 2014. Soil temperature and moisture were also monitored at the same time. 【Result】The mean soil temperature of C. carlesii forest in NL,DL,and CK were 18. 2,18. 05,and 17. 98 ℃,respectively. And the mean soil temperature of C. carlesii plantation in NL,DL,and CK were 18. 68,18. 70,and 18. 76 ℃,respectively. The results showed that soil temperature did not change significantly among different sample plots. However,the soil temperature was significantly larger in plantation than in natural forest. Litter respiration increased significantly from 11. 8% to 29. 7% in C. carlesii plantation. DL significantly increased soil respiration by 25. 2%（P 〈 0. 05） in C. carlesii forest,indicatingpriming effects. But there were no significant change in C. carlesii plantation with DL treatment,which had no priming effects. A very significant exponential relationship was founded between soil respiration and soil temperature at 5 cm soil depth in litter manipulation plots（P 〈 0. 001）,while a significant linear relationship was found between soil respiration and soil moisture at 0- 10 cm depth in all study plots（P 〈 0. 05）.【Conclusion】The results sugg