兴国县森林土壤有机碳库及其与环境因子的关系

Organic carbon pool of forest soil and its relationship to environment factors in Xingguo county of Jiangxi province

确定土壤有机碳的储量、空间分布 ,对土壤碳循环的研究具有重要意义。根据江西兴国县 84个样点和 50个剖面的采样数据、土壤有机质含量 ,统计土壤各类型分布面积 ,估算了土壤有机碳库。研究结果表明 ,兴国县森林土壤有机碳在 2 0cm深度内总量为 559 38× 1 0 4t,平均有机碳密度为 2 47kgC/m2 ,在 1 0 0cm深度内总量为 1 4 37 1 9× 1 0 4t,平均有机碳密度为6 36kgC/m2 。其分布特征是 :西北部和东北部高 ,中部和西南部低。土壤有机碳含量深受母岩、植被和地形影响 ,在表层 (0～ 2 0cm) ,坡向和有机碳含量呈显著正相关关系 ;海拔与有机碳含量呈极显著正相关关系 ;在剖面 (0～ 1 0 0cm) ,海拔和有机碳含量的相关关系达极显著水平 ,有机碳含量与坡向、坡度之间无明显的相关关系。

Soil organic carbon is the main part of terrestrial carbon pool. It plays an important role in terrestrial carbon cycle and is one of the important components in the research of global change, so it is important for soil carbon cycle to ascertain soil organic carbon reserves and spatial distribution in soil carbon cycle research. This paper adopted the soil distribution areas, sampling data and soil organic contents from 84 samples and 50 profiles to estimate soil carbon pool in Xingguo county of Jiangxi province. The calculation results show that parent material has influence on contents of soil organic carbon, soil derived from lime rock has higher levels of organic carbon (17.92 g/kg) in surface layer(0-20 cm),soil derived from red sandstone has lower levels of organic carbon (6.11 g/kg); and contents of soil organic carbon increased in turn from red clay,red sandstone, granitic, phyllite to lime rock. The contents of soil organic carbon vary greatly under different vegetation types.Soil under pin (Pinus massonniana) has lower levels of organic carbon, but soil under fir(Cunninghamia lanceolata) or broad-leaved forest has higher levels of organic carbon. The total amount of soil organic carbon is about 559.38×10 4t and organic carbon density is about 2.47 kgC/m 2 in depth of 20cm, the total amount of soil organic carbon is about 1437.19 10 4t and organic carbon density is about 6.36 kgC/m2 in depth of 100cm. The distribution of soil organic carbon density is high in the northwest and northeast but low in the middle and southwest in Xingguo county. Soil organic carbon and topographic variables have correlations. In topsoil(0-20cm), the correlations of aspect and the content of soil organic carbon is positively significant while that of elevation and the content of soil organic carbon is highly significant. In profile(0-100cm), the correlation of elevation and the content of soil organic carbon is significant while the content of soil organic carbon and aspect and slope grade have no obvious correlations.