中文摘要：

为阐明退耕湿地植被恢复对土壤氮素的影响,以黄河中游湿地河南武陟渠首段为研究对象,分析滩区耕地和退耕恢复区3种典型湿地植被群落土壤pH、有机质、总氮、硝态氮、铵态氮和氮储量的变化。研究结果表明,随着退耕恢复时间的增加,土壤pH呈下降趋势;土壤有机质、总氮总含量和氮储量呈逐渐增加趋势,分别由未恢复前的7.69∽10.08g/kg,174.44∽344.13mg/kg和0.07∽0.09kg/m2增加到恢复1.5a后的15.83∽29.53g/kg,739.13∽1 076.99mg/kg和0.22∽0.33kg/m2。恢复区土壤有机质、总氮总含量在空间上的变化表现为上层大于下层,土壤硝态氮含量均低于氨态氮含量。不同湿地植被土壤中总氮、有机质含量和氮储量存在显著差异（P〈0.05）,其含量大小均依次为水蓼群落〉水烛群落〉芦苇群落。相关分析结果表明,研究区土壤中有机质含量与总氮之间存在极显著正相关关系（r=0.80;P〈0.01）,铵态氮含量与有机质、总氮之间均存在极显著正相关关系（r=0.69,0.50;P〈0.01）,硝态氮含量和有机质、总氮、铵态氮之间均存在一定正相关性,土壤pH与有机质和总氮之间均存在显著负相关关系（r=-0.49,-0.46;P〈0.05）。

英文摘要：

In order to clarify the effect of wetlands recovered from farmlands on the soil characteristics, soil samples of different plant communities were collected in the degraded and restored riparian wetlands of the middle Yellow River at Wuzhi, Henan province. And the distribution characteristics of organic matter, total nitrogen, nitrate nitrogen, ammonium nitrogen, and nitrogen stocks in the soil samples were studied. It was found that with increasing recovery time, pH values generally decreased in the soils, while the content of organic matter, total nitrogen, and nitrogen stocks in the soil increased. The content of organic matter, total nitrogen, and nitrogen stocks were 7. 69--10.08 g/kg, 174. 44--344. 13 mg/kg, 0. 07--0.09 kg/m2 and 15.83--29.53 g/kg, 739.13--1 076.99 mg/kg, 0.22--0.33 kg/m2 before and after one and a half years arti- ficial restoration, respectively. The upper soil layer （0--20 cm） had more organic matter and total nitrogen than the lower soil layer （20--40 cm） in the restored sites, and the content of ammonium nitrogen was higher than nitrate nitrogen. Plant communities significantly （P〈0.05） influenced the contents of organic matter, total nitrogen, and nitrogen stocks, with the effect decreasing in the order of Polygonum hydropiper communities〉Typha angustifolia communities〉Phragmites australis communities. There was highly significant positive correlation between organic matter and total nitrogen （r=0.80; P〈0.01）, and highly significant positive correlations between ammonium nitrogen and organic matter and total nitrogen （r=0.69, 0.50; P〈0.01）. However, nitrate nitrogen was not significantly correlated to total nitrogen, organic matter, and ammonium nitrogen. Furthermore, there were significant negative correlations between pH values and organic matter, total nitrogen （r=--0.49,-0.45;P〈0.05）.