安徽省升金湖湿地土壤有机碳储存及分布

文章研究了安徽省升金湖湿地土壤有机碳储存和分布特征及其与土壤氮素的关系。结果表明,供试湿地土壤全土1m深有机碳密度达10.82±1.90kg.m-2,表层土壤(0—30cm)有机碳密度为5.19±0.68kg.m-2,高于报道的人工湿地——水稻土的碳密度;有机碳(SOC)含量分布随土壤深度(H)的递降符合幂函数方程,湿地土壤有机碳的表层积累强度和积累深度高于稻田;湿地土壤氮素是土壤固碳的有利因子,其氮素对土壤有机碳积累的效应高于水稻土;因湖泊沉积受河流动力学、土壤水分和植物生长条件的影响,湿地土壤有机碳含量存在显著的水平空间变异性。看来,长江中下游淡水湿地在陆地生态系统碳氮储存上具有重要意义。

STORAGE AND DISTRIBUTION OF SOIL ORGANIC CARBON IN SHENGJIN LAKE WETLAND, ANHUI, CHINA

The storage and profile distribution as well as the horizontal spatial variation of wetland soil organic carbon(SOC) in the Shengjin Lake Wetland were studied in this paper.The wetland soils have a higher SOC storage,i.e.,10.82 to 1.90 kg.m-2 for the whole 1 m profile and of 5.19 to 0.68 kg.m-2 for topsoil(0-30cm),than that reported for adjacent paddy field,man-made wetland and paddy soil.The distribution of SOC down to the profile followed a significant power function with depth other than exponential functions reported for natural forest soils and generally for croplands,being much stronger SOC accumulation in topsoil than in paddy field.Significant correlation of SOC with total N supported that soil N favored SOC accumulation through enhancing grass growth at the time of emergence,which is more intense than for paddy field comparatively.There existed a profound horizontal variation of SOC both at topsoil and at bottom as affected by the deposition of soil material and the grass growth depending on the submergence condition in different directions toward the rivers entering the lake.The wetlands in the lower reaches of the Yangtze River may have significance in C and N storage in the terrestrial ecosystem.