加拿大一枝黄花入侵对杭州湾湿地围垦区土壤酶活性的影响

Effects Solidago canadensis Invasion on Soil Enzyme Activities in the Hangzhou Bay Reclaimed Wetlands

为了阐明加拿大一枝黄花(Solidago canadensis)入侵对土壤养分循环产生的影响及机理,以杭州湾滨海湿地围垦区内分布的加拿大一枝黄花群落与3种土著植物群落:束尾草(Phacelurus latifolius)群落、芦苇(Phragmites australis)群落和白茅(Imperata cylindrica)群落为研究对象,研究了外来植物入侵对土壤酶活性的影响及其与土壤养分关系的影响.结果表明:加拿大一枝黄花群落0~10cm土层土壤脲酶活性显著高于束尾草、白茅和芦苇(P<0.001),分别提高了91.49%、116.97%和334.88%;加拿大一枝黄花入侵也显著提高了土壤蔗糖酶活性和碱性磷酸酶活性(P<0.01).相关性分析表明:土壤碱解氮、硝态氮和铵态氮含量和脲酶活性呈显著正相关(P<0.01),土壤全磷含量与碱性磷酸酶活性呈显著正相关(P<0.05),土壤全磷、碱解氮、铵态氮和全氮含量与蔗糖酶活性呈显著正相关关系(P<0.05),土壤全磷、碱解氮和全氮含量都与β-淀粉酶活性呈显著的正相关关系(P<0.05),土壤全磷、碱解氮、硝态氮、铵态氮、全氮和有机质含量都与β-葡萄糖苷酶活性呈显著的正相关关系(P<0.05).加拿大一枝黄花入侵显著提高了部分土壤酶的活性.这些土壤酶活性的变化可能加速了土壤养分转化,有利于其进一步入侵.

Solidago canadensis is one of the worst hazardous invasive plants in China.The effects of S.canadensis invasion on soil enzyme activities and the relationship between soil enzyme activity and soil nutrients content were investigated in four plant communities dominated by S.canadensis,Phacelurus latifolius,Phragmites australis and Imperata cylindrica,respectively,from the Hangzhou bay reclaimed wetlands in Ningbo city,Zhejiang province.The results showed that in 0~10 cm soil layer the urease activities from S.canadensis community were extremely significantly higher than that of P.latifolius,I.cylindrica and P.australis(P<0.001).The urease activities were increased by 91.49%,116.97%and 334.88%,compared with the above three native plant community soils,respectively.The soil saccharase activities and alkaline phosphatase were also significantly enhanced by S.canadensis invasion(P<0.01).Correlation analysis showed that the soil urease activities and soil NH 4-N content,NO 3-N content and available nitrogen content were positively correlated(P<0.01).The soil alkaline phosphatase activities were significantly positively correlated with soil total phosphorus content(P<0.05).The soil saccharase activities were positively correlated with soil total nitrogen content,NH 4-N content,available nitrogen and total phosphorus content(P<0.05).Theβ-amylase activities were significantly correlated with the soil total nitrogen content,available nitrogen content and total phosphorus content(P<0.05).Theβ-glucosidase activities were significantly correlated with soil organic matter content,total nitrogen content,NH 4-N content,NO 3-N content,available nitrogen content and total phosphorus content(P<0.05).In conclusion,S.canadensis invasion significantly affected some key soil enzyme activities and the altered soil enzyme activities may affect soil nutrient transformation and availability.