中文摘要：

为了解意大利苍耳入侵对土壤生态方面的影响,以本地植物狗尾草为对照,比较研究了意大利苍耳入侵对土壤酶活性及土壤肥力的影响.结果表明,意大利苍耳入侵显著提高了土壤中速效钾、有效磷、有机质和水解性氮的含量,增强了入侵域土壤中蔗糖酶、脲酶、酸性磷酸酶、多酚氧化酶和过氧化物酶的活性.蔗糖酶活性与速效钾、水解性氮含量之间的相关性分别达到显著正相关；脲酶活性与速效钾、有机质、水解性氮含量之间的相关性呈不同程度的正相关,与有效磷含量呈负相关.与本地植物狗尾草相比,意大利苍耳改变了土壤养分的供求平衡,这种改变可能有利于意大利苍耳的生长竞争和对本地植物狗尾草生长的抑制；不同植物群落根际土壤酶活性差异可能是引起土壤肥力变化的重要驱动因子之一.

英文摘要：

To understand the influence of the invasive speices Xanthium italicum Moretti on soil ecological as- pects, compared to native plants Setaira viridis （L.）Beauv, the influence of X. italicun on soil enzyme activi- ties and soil fertility was carried out. The results showed that the invasion of X. italicum had significantly im- proved the soil available potassium, effective phosphorus, hydrolysis of organic matter and nitrogen content, and increased the activity of invertase, urease, acid phosphatase, polyphenol oxidase and peroxidase com- pared with that of native species, respectively. The correlation analysis showed that soil enzyme activities are closely related to the soil fertility. Compared with native plants S. viridis, Xanthium italicum changed the soil nutrient supply and demand balance, this change may be beneficial to the growth of the Xanthium italicum competition and inhibition Setaria viridis growth; the differences between rhizosphere soil enzyme activity of different plant communities could be one of the important driving factors of the change of the soil fertility.