鄱阳湖湿地泗洲头洲滩浅层土壤氮素的时空特征

湿地是全球氮循环的N源、N汇和N转化器,自然湿地氮的研究对于揭示生态系统氮循环的规律具有重要意义.以鄱阳湖湿地泗洲头为研究区域,根据湿地海拔高程梯度(10～17 m)采取表层土壤0～20 cm土层样品,分析了土壤全氮、铵态氮、硝态氮、碱解氮的空间分布特征.结果表明:鄱阳湖湿地泗洲头表层土壤氮含量空间分布较为复杂,0～10 cm土层的氮含量和10～20 cm土层的氮含量呈现相似的梯度特征,0～10 cm土层的土壤氮含量要高于10～20 cm土层的土壤氮含量,其中0～10 cm土层和10～20 cm土层的全氮、铵态氮、碱解氮含量最高均值出现在高程13～14 m,硝态氮最高均值出现在高程16～17 m.利用SPSS双变量中的pearson相关性检验表层土壤全氮、铵态氮、硝态氮、碱解氮与地上生物量、土壤pH值、土壤含水量、年均淹水时间、高程之间的相关性,结果表明:土壤氮素与地上生物量的相关性在统计学意义上最为显著,而与其他环境因素的相关性并不明显.这反映了鄱阳湖泗洲头表层土壤氮含量的空间分布与积累过程受干扰的因素比较复杂.

The Temporal-Spatial Characteristics for N in Surface Soil in Sizhoutou Marshland of Poyang Lake Wetlands

Wetland was a N source,N pool,N convertor in global N cycle,and it help probe the rhythm of N cycle of ecosystem as an important significant.The marshland of Poyang Lake was an example to analyze the soil nitrogen(including total nitrogen(TN),ammonium nitrogen(NH⁺₄-N),nitrate nitrogen(NO^-₃-N),alkali-hydrolyzable nitrogen(AHN))in surface soil with a depth 0-20 cm to be sampled from the elevation 10 m to 17 m.The result explained spatial characteristic of soil nitrogen was similar in 0-10 cm and 10-20 cm.The average highest value of TN,NH⁺₄-N,AHN was in elevation 13-14 m,and The average highest value of NO^-₃-N was in elevation 16-17 m..The correlation of N,overground biomass,inundation period,PH,moisture content and elevation was analyzed according to Pearson correlation,the correlation between TN,NH⁺₄-N,NO^-₃-N,AHN and environmental condition was no significant,however,overground biomass is significant correlation with N.The correlation between N and environmental condition explained the complex of spatial distribution and circulation mechanism in N in Poyang Lake wetlands.