不同植被和水文条件下苏北盐沼土壤TN、TP和OM剖面特征

以盐城国家珍禽自然保护区盐沼湿地为例,分析了不同植被带土壤中全氮(TN)、全磷(TP)和有机质(OM)的剖面变化特征,探讨了盐沼植被和水文条件对TN、TP和OM剖面变化的影响。结果表明:不同植被带土壤中TN、TP和OM含量变化显著,其中,互花米草带中的TN和OM含量最高,分别为(0.96±0.09)g/kg和(17.26±0.80)g/kg;光滩中TN和OM含量最低,分别为(0.07±0.01)g/kg和(0.98±0.13)g/kg,而光滩中TP含量最高,为(0.98±0.03)g/kg。不同植被对土壤TN、TP和OM等养分的转化、吸收、累积过程具有不同程度的影响;另外,由人工围堰和淡水补给引起的水文条件变化通过影响土壤的盐分,进而影响植被的分布,最终对整个盐沼生态系统土壤中TN、TP和OM的剖面变化产生重要的影响。

Effects of vegetation and hydrological conditions on the profile characteristics of TN, TP and OM in coastal salt marshes in northern Jiangsu Province

We investigated the spatial distribution of total nitrogen (TN), total phosphorus (TP) and organic matter (OM) in the soils of coastal salt marshes in the Yancheng National Rare Bird Reserve, northern Jiangsu Province. We analyzed the effects of vegetation and hydrological conditions on the variations of TN, TP and OM. Results indicate that spatial variations of TN, TP and OM were significantly different among the vegetation zones. The highest amounts of TN ((0.96±0.09)g/kg) and OM ((17.26±0.80)g/kg) (mean±standard deviation) were found at the Spartina alterniflora marsh, while the lowest amounts of TN ((0.07±0.01)g/kg) and OM ((0.98±0.13)g/kg) were found in mudflats. The highest amount of TP ((0.98±0.03)g/kg) was also found in mudflats. Our findings suggest that vegetation play an important role in the process of transportation, absorption and accumulation of TN, TP and OM. By changing the salt in the soil and thus vegetation distribution, the variation of hydrological conditions, due to the construction of a cofferdam and freshwater supplies, indirectly affects the distribution of TN, TP and OM in the soil profiles of the salt marsh ecosystem.