桂西北典型喀斯特峰丛洼地退耕还林还草的固碳效益评价  

Evaluation of carbon sequestration after conversion of cropland to forest and grassland projection in karst peak-cluster depression area of northwest Guangxi,China

作　　者：刘淑娟[1,2,3] 张伟[1,2] 王克林[1,2] 苏以荣[1,2] 

机构地区：[1]中国科学院亚热带农业生态研究所,亚热带农业生态过程重点实验室,长沙410125 [2]中国科学院环江喀斯特生态系统观测研究站,环江547100 [3]中国科学院大学,北京100049

出　　处：《生态学报》2016年第17期5528-5536,共9页Acta Ecologica Sinica

基　　金：战略性先导科技专项(XDA05070403);国家重点基础研究发展计划(2015CB452703);国家自然科学基金项目(31270555;31270551);中国科学院西部之光人才培养项目

摘　　要：退耕还林还草作为桂西北喀斯特地区主要的土地利用转变方式,对该区域产生了积极的生态效益。就退耕还林还草政策的实施对该区域土壤有机碳储量的影响进行评价。结果表明:1)将剖面碳密度与深度做对数拟合得到的参数进行协同克里格插值的方法能较准确估算研究区碳密度,R2为0.723;2)退耕还林还草措施对土壤有机碳(SOC)含量产生了显著的影响,耕地(19.3 g/kg)转变为牧草(23.5 g/kg,退耕近10a)和草地(34.6 g/kg,退耕30a)的SOC含量均有增加,转变为人工林(17.8 g/kg,退耕8a)的SOC含量略有下降;3)退耕还林还草工程实施后研究区土壤碳储量提高了23.43%,退耕后单位面积土壤碳储量为2938 t C/km^2;4)种植牧草兼顾固碳效益和经济效益,是一种较好的退耕模式。Understanding the effect of vegetation restoration on soil carbon sequestration is one of the important pathways to evaluate the performance of ecological restoration efforts, and is valuable in estimating the potential of humans for climate change adaptation. In the 1980s and late 1990s, owing to the Ecological Immigrants Project and Grain for Green Project, wide spread conversions of cropland to grassland and forest have happened in the karst region in Southwest China. Several studies have been carried out to determine the changes of vegetation carbon storage induced by land cover change in this region. However, because of the high inherent terrain variability of the karst landscape, relatively little is known about the accurate size of the current soil organic carbon （SOC） storage and the degree of human-induced changes. Therefore, the objectives of this study were to develop an appropriate method for estimating SOC storage in a typical karst landscape at a local scale and to estimate SOC change responding to vegetation restoration due to the Grain for Green Project. For this study, a 200 m×200 m grid was established over the study site （10.24 km^2） and a total of 249 surface soil samples （0-15 cm） were collected in 2011, and 81 soil profiles were investigated by vegetation type （cropland, forage, plantation, regressed land, shrub land, secondary forest） in 2009 and 2011. The profiles of the soil samples were separated into depth segments：0-10, 10-20, 20-30, 30-50, 50-70 cm, and 70-100 cm. The maximum sampling depth was not greater than 100 cm and soil depth less than 100 cm was sampled to bedrock. A total of 424 samples from 81 profiles were collected. Vegetation type, canopy cover, slope, aspect, soil depth, and rock exposure （4 m×4 m） were recorded for each sample point. Additionally, soil depth and rock exposure were measured at 150 randomly selected points in the study area. All data were transformed for normality of distribution and homogeneity of variance prior to analysis. Pears

关 键 词：喀斯特 峰丛洼地 退耕还林还草 固碳效益 

分 类 号：Q948.1[生物学—植物学]