海河流域平原区土壤碳密度分布特征和碳储量估算

基于2003年以来多目标区域地球化学调查积累的大量表、深层土壤有机碳、全碳分析数据,以土壤类型和土地利用类型为基本计算单元,本文重点对海河流域平原区土壤碳密度与碳储量分布规律进行了研究.结果表明:海河流域表、深层土壤全碳和有机碳密度空间分布规律基本一致,总体均表现为"北东呈带、区域连片","南部高于北部,山前高于平原,城市高于农田"的特征.从土壤类型上看,湿潮土的有机碳密度最高,为17.92 kg/m2,其次为石灰性褐土,达到15.49 kg/m2,草甸风沙土的有机碳密度最低,为7.9 kg/m2;有机碳密度最大者与最小者相差将近2倍.从土地利用类型来看,耕地的有机碳密度最高,这与近年来推广的秸秆还田和人工施肥有关.

Distribution Characteristics of Soil Carbon Density and Carbon Reserve Estimation in the Plain Areas of Haihe River Basin

The soil carbon pool has become the focus and heated points of research on global change, and achieved remarkable results in our country. However, the research on soil carbon pool in the plain areas of Haihe river basin still remains blank. This research is based on the abundant analytic data of organic carbon and total carbon for both top soil (0~0.2 m) and deep soil (0~1.8 m) obtained during Multi-Purpose Regional Geochemi-cal Survey since 2003. Using soil types and land use types as the basic computing unit, the research deals with soil carbon density and carbon reserve in the plain areas of Haihe river basin. The results show that the spatial density distribution of both total carbon and organic carbon are basically the same in top soil and deep soil in the Haihe river basin. Generally the values are higher in the south than that in the north, the values in piedmont areas are higher than that in plain areas, and the values in urban areas are higher than that in farmland areas. The results based on the soil types show that wet soil contains the highest organic carbon density, up to 17.92 kg/m2, fol-lowed by the calcareous cinnamon soil, up to 15.49 kg/m2, and the meadow aeolian sandy soil contains the low-est, 7.9 kg/m2. The maximum is nearly 2 times of the minimum, affected by the water and clay content in the soil. The results based on the land use types show that the cultivated land contains the highest organic carbon density, due to popularization of straw returning and artificial fertilization in recent years.