水保所知识产出(1956---)知识库

通过对上黄小流域不同土地利用方式下114 个样点的采样分析，结合地统计学原理对小流域不同土层土壤有机碳密度的
空间变异程度进行研究。研究表明，除表层土壤有机碳密度的空间变异程度较弱外，其余两层均属于中等强度变异。并呈现东
部天然草地分布区与中部带状灌丛林地分布区空间变异程度较强的分布特点。不同土层深度和土地利用方式下土壤有机碳密
度存在明显差异，土壤有机碳含量随着土层深度的增加而逐渐减小，有机碳密度则表现为10—30cm 最高， 30—60cm 其次，0—
10cm 最低。不同土地利用方式下，有机碳密度表现为: 天然草地＞果园＞灌丛林地＞河滩、河台地＞撂荒地＞人工草地＞耕地。以
土地利用方式为基本单元，对上黄小流域土壤有机碳储量进行估算。结果表明，上黄小流域土壤有机碳总储量为46527． 12t，其
中，灌丛林地( 22052． 81t) 和天然草地( 14573． 14t) 的储量最高，占总储量的78． 72%。

An analysis of 114 sampling points was conducted in the Shanghuang catchment under different land uses in hilly
regions of the Loess plateau． Combined with the geo-statistics method，this study focused on the spatial variation of soil
organic carbon ( SOC) density with land use and soil depth． The results indicated that the spatial variability of SOC density
was low intensity at a depth of 0—10 cm，and middle intensity at 10—30 cm and 30—60 cm． Higher spatial variations
were distributed in the natural grassland area to the east and the shrub land in the middle of this small watershed． Soil
organic carbon density was significantly different among land uses and soil profile depths; it deceased as soil depth
increased． At different depths，the highest SOC density value was in the 10—30 cm layer，and lowest in the 0—10 cm
layer． For different land uses，the SOC density showed the following trend: natural grassland ＞ orchard ＞ shrub land ＞
terrace cropland ＞ abandoned farmland ＞ manmade grassland． According to the estimated SOC stock，the total stock of the
Shanghuang catchment was 46527． 12 t and the carbon storage of shrub land ( 22052． 81 t) and natural grassland ( 14573．
14 t) accounted for 78． 72% of the total．