中文摘要：

【目的】土壤碳库管理指数是表征土壤碳变化的重要量化指标,研究黄土丘陵区人工刺槐林土壤活性有机碳与碳库管理指数的变化过程对认识该地区生态恢复过程中土壤质量的演变及其效果评价具有重要意义。【方法】采用时空互代法,以典型侵蚀环境纸坊沟流域生态恢复过程中不同年限的人工刺槐林为研究对象,选取坡耕地和天然侧柏林为参照,分析了植被恢复过程中土壤有机碳（TOC）、活性有机碳（LOC）、非活性有机碳（NLOC）及碳库管理指数（CPMI）的演变特征,并运用相关和回归分析方法对生态恢复过程中碳库各组分和恢复年限进行拟合。【结果】营造刺槐林可以显著增加土壤碳库各组分含量,并随恢复年限呈显著线性关系,50a时TOC、LOC、NLOC和碳库指数（CPI）分别较坡耕地增加271%、174%、467%和271%,其中NLOC增加速率略高于LOC,表明植被恢复增加的土壤碳素绝大多数以非活性形态贮存起来,而为了满足生物生长所必须的活性物质来源,土壤碳库必须维持一定的活度状态来满足碳素的动态转化平衡,碳库管理指数在营造刺槐林初期显著降低,随后先增加后降低,与刺槐林生长特性密切相关;但与天然林相比差距仍然较大,恢复50a时TOC、LOC和NLOC仅为侧柏林的49%、34%和61%。【结论】侵蚀环境下的坡耕地由于人为干扰,土壤碳库含量偏低,并处于高速低效率物质转化过程中,人工刺槐林促进生态恢复可以依靠生物的自肥作用增加土壤碳库各组分含量,但要恢复到破坏前该地区顶级群落时的水平,还需要一个漫长的阶段,这个阶段可能需要上百年的时间。

英文摘要：

【Objective】 Soil labile organic matter and carbon management index are important parameter representing carbon cycle in soil ecosystem. Study on dynamics of them in the artificial Robinia in loess hilly area so as to understand the change and effect evaluation during process of ecological restoration is of great importance. 【Method】 The research regarded Zhifanggou small watershed in typical erosion environment as a study plot, the selected artificial Robinia grown in different times were used as objects of study, the interchangeablely space-time method was adopted and the sloping cropland and the plot where the Platycladus orientailis are grown were used as contrasts. Several indexes were analyzed such as TOC, LOC, NLOC and evolution characters of carbon management index in the period of ecological restoration. 【Result】 The study indicates that the content of soil carbon is on the low side because human behavior has a negative effect on sloping cropland. However, the content of every group soil carbon increased drastically by planting Robinia. With the increasing of the time of conservation, the relationship is very remarkable. After 50 years of restoration, the content of TOC, LOC, NLOC and AI in the study plot increased by 271%,174%, 467%, and 271%, respectively, compared with sloping cropland. The increasing speed of NLOC was faster than LOC. It is assumed that the increasedcarbon by restoration is stored in an inactive form to produce active matter which is necessary for biont. And the soil carbon must keep active to fulfill the balance of carbon dynamic transformation. At initial stages, soil carbon management index increased remarkably. Later it increased but is then declined eventually. The rate of the content of TOC, LOC and NLOC in the study plot grown with Robinia was 49%, 34% and 61% of the control respectively. 【Conclusion】 The results suggested that it is impossible to increase the content of every group soil carbon by planting Robinia in the loess hilly area, but much longer time, c