摘要
[目的]揭示不同恢复年限的天然草地土壤碳库动态变化及其剖面分布特征,全面认识和理解天然草地恢复下土壤有机库、无机碳库的动态特征。[方法]采用野外调查与室内试验分析相结合的方法,以农田为对照,对黄土丘陵区不同恢复年限（11,16,22和35a）的天然草地土壤有机碳（SOC）、无机碳（SIC）、总碳（STC）的动态变化及其剖面分布特征进行了探讨。[结果]（1）天然草地恢复过程中表层（0—10cm）SOC含量随植被恢复年限显著增加,下层（10—100cm）SOC含量随植被恢复年限变化不明显;0—100cm土层SOC储量呈先减少后增加趋势,但仍未达到农田SOC储量的水平。（2）天然草地0—20cm土层SIC含量呈相对脱钙现象,0—100cm土层SIC库储量约为SOC库储量的2.7～4.5倍。土壤无机碳库随植被恢复年限的增加无明显变化,但SIC的剖面分布深度发生改变。（3）土壤总碳库随恢复年限增加无明显变化,0—100cm土层SIC储量在STC库中所占比例约为75.6%～86.0%。[结论]短时间内天然草地的土壤碳汇效应并不明显,碳库增汇效应需要长期的过程。
[Objective]This Paper aimed to investigate the dynamic variation and distribution of soil carbon of natural grassland under different restoration years in order to understand the dynamic characteristics of soil organic and inorganic carbon pool.[Methods]Using field survey and laboratory analysis method,this study analyzed the dynamic variation of soil total carbon of natural grassland under different restoration years（11,16,22 and 35a）in loess hilly region.[Results]Soil organic carbon（SOC）content in the 0—10cm soil layer surface was increased significantly with the increase of restoration years,while no evident changes were found in the10—100cm soil layer.Variations in average soil organic carbon storage of natural grassland at 0—100cm soil depth decreased initially and then increased with the increase of restoration years.However,it had not reached to the level of farmland.Decalcified phenomenon existed in 0—20cm soil layer.Soil inorganic carbon（SIC）storage was 2.7to 4.5times larger than soil organic carbon storage in 0—100cm total soil layers.No significant variations occurred in total soil carbon storage as the restoration years increased.Soil inorganic carbon storage accounted for about 75.6%to 86.0% of soil total carbon storage in the 0—100cm soil.The SIC pool was an important factor that influenced soil total carbon pool in the study area,which also main-tained the dynamic balance of soil carbon pool in this region.[Conclusion]In the semi-arid environment of the Loess Plateau,soil carbon sequestration effect in natural grassland is not obvious and the improvement of soil carbon pool is likely to require a considerably long period of time.
出处
《水土保持通报》
CSCD
2015年第5期49-54,共6页
Bulletin of Soil and Water Conservation
基金
国家自然科学基金资助项目"黄土高原植被自然恢复过程中土壤有机碳来源判定与周转特征"(41301610)
陕西省青年科技新星项目(2014KJXX-52)
霍英东教育基金会高等院校青年教师资助项目(131025)
中国科学院重点部署项目(KZZD-EW-04)
关键词
天然草地
土壤有机碳
土壤无机碳
碳储量
黄土高原
natural grassland
soil organic carbon
soil inorganic carbon
soil carbon storage
Loess Plateau
