外来植物豚草入侵对土壤碳氮转化的影响

选取撂荒田地为试验样地，以入侵植物豚草（Ambrosia artemisiifolia L.）为对象，以土著优势物种窃衣（Torilis scabra Thunb.）为参照，通过对入侵植物和土著植物根际土壤的采样分析，研究了入侵植物对入侵地土壤特性及土壤碳氮转化的影响。结果表明，与土著物种窃衣相比，豚草入侵使土壤有机质含量增加89.13%，全氮含量增加42.15%，铵态氮含量增加43.69%，硝态氮含量增加35.36%，微生物量碳增加52.08%，微生物量氮增加61.26%，氮净矿化速率增加1.41倍，氮净氨化速率增加206倍，但硝化速率和反硝化速率变化不明显。由此可见，豚草显著改变了入侵地土壤的理化特性，加速了土壤碳氮转化过程。

Effect of invasive plants Ambrosia artemisiifolia L. on soil carbon and nitrogen transition

 To examine the effects of alien plants invasion on soil properties and soil carbon and nitrogen transition， the rhizosphere soil samples were collected under invasive plants， Ambrosia artemisiifolia L.， and the neighboring indigenous species， Torilis scabra Thunb. in a deserted paddy field. It was shown that contents of soil organic carbon， total nitrogen， nitrate and ammonium were increased by 89.13%， 42.15%， 43.69% and 35.36%， respectively， with the invasive plants， Ambrosia artemisiifolia compared to those with indigenous species. Similarly， soil microbial carbon and nitrogen biomass were increased by 52.08% and 61.26%， respectively， with the invasive plants. Under similar laboratory incubation conditions， soil mineralization and ammonification rates were increased by 141% and 206%， respectively， due to Ambrosia artemisiifolia invasion as compared to that of indigenous species. However， the effects of Ambrosia artemisiifolia invasion on soil nitrification and denitrification were not obvious. In conclusion， the present study revealed a significant shift in soil properties due to alien plants invasion. Soil carbon and nitrogen process was substantially facilitated， which may create a positive feedback as a consequence of alien plants invasion.