金钟藤蔓延成灾对土壤理化性质及土壤酶活性的影响

Spread and explosion of Merremia boisiana on physical and chemical properties and enzyme activity in soil ecosystem

为了探讨金钟藤表现出的入侵性对土壤生态的影响机制,通过采样分析,比较了本地有害植物金钟藤不同覆盖程度的土壤理化性质以及土壤酶活性的变化规律。结果表明:金钟藤覆盖程度的加深,显著提高了土壤有机质、全氮、铵态氮、硝态氮、有效磷和速效钾的含量,而降低了土壤全磷的含量,但对全钾含量的影响不显著;同时也显著提高了土壤蔗糖酶、脲酶和磷酸酶的活性。有机质、全氮、铵态氮、硝态氮、有效磷和速效钾的含量在重度覆盖土中分别达44.96、2.57 g/kg和8.96、17.42、1.37、12.67 mg/kg,分别是裸土的4.40、10.28、2.30、1.57、1.83、1.90倍。在重度覆盖土中,蔗糖酶、脲酶和磷酸酶活性分别为3.39、0.52、7.70 mg/g,分别是裸土的2.92、2.26、1.39倍。可见,金钟藤改变了土壤理化性质和土壤酶活性,形成对自身生长有利的微生态环境,这可能是其能够成功入侵新区域和快速蔓延扩张的生态机制之一。

In recent years, the spread and explosion of Merremia boisiana in Hainan has significantly threatened biodiversity and ecosystem functioning in the locality. The purpose of the study was to understand the impacts of the invasion of M. bosiana on the soil ecosystem properties. Through the analysis of sampling, we compared the changing patterns of soil physical and chemical properties and soil enzyme activities with the change in the level of invasion by the native harmful plant M. boisiana. The results showed that with the increase of the coverage, M. boisiana increased the soil organic matter, total nitrogen, ammonium nitrogen, nitrate nitrogen, available phosphorus, available potassium content,reduced the soil total phosphorus content, did not affect total potassium content, and also increased the activities of sucrase,urease and phosphatase. Organic matter, total nitrogen, ammonium nitrogen, nitrate nitrogen, available phosphorus and available potassium content in the heavily-covered soil was 44.96, 2.57 g/kg, 8.96, 17.42, 1.37, 12.67 mg/kg, which was4.40, 10.28, 2.30, 1.57, 1.83 and 1.90 times as that in the non-covered soil. The activities of sucrase, urease and phosphatase in the heavily-covered soil was 3.39, 0.52, 7.70 mg/g, which was 2.92, 2.26, 1.39 times as that in the non-covered soil. The results indicated that M. Boisiana changed the soil physical and chemical properties and enzymeactivities, probably creating a favorable soil environment for itself. This may be one of the ecological mechanisms underlying its invasion success and rapid expansion.