鄱阳湖湖滨湿地土壤酶活性及影响因素

Soil enzyme activity and influencing factors in lakeside wetland of Poyang Lake,Jiangxi Province of eastern China

为探讨湖滨湿地土壤酶活性变化规律及其影响因素，以鄱阳湖滩地为研究对象，在2011年的2、5、9和11月分别采集0～10cm的土壤样本，对土壤性质和与有机碳转换相关的土壤酶活性进行测定，并分析了土壤性质与酶活性的相关性。结果表明，不同月份的土壤pH值、有机碳和氮含量的差异不显著，但土壤酶活性变化有显著差异。纤维二糖酶和卢一糖苷酶活性在9月份达到最大值；而酚氧化酶活性在2月份最高，9月最低；过氧化物酶活性则在11月最高；己丁质酶活性未表现出显著差异。相关分析表明，土壤水分含量与酚氧化酶和过氧化物酶活性呈极显著相关；地表温度与纤维二糖酶活性呈显著正相关，而与过氧化物酶活性呈极显著负相关。土壤有机碳和全氮与卢一糖苷酶呈显著负相关，而与过氧化物酶呈极显著正相关。综合分析认为，湖滨湿地土壤水分的变化显著影响不同土壤酶的活性，而土壤有机碳和氮对土壤酶活性的影响相对较小。

In order to elucidate the change of soil enzyme activity and its influencing factors, we collected soil samples from 0 to 10 cm depth in February, May, September and November 2011 in lakeside wetland, Poyang Lake of eastern China, and measured the soil properties and soil enzyme activities related to organic carbon transformation, meanwhile the relationships between soil enzyme activities and soil properties were examined. The results showed that the changes of soil pH, the concentrations of organic carbon and total nitrogen were not significant through different months in a year. However, the changing trends of soil enzyme activities were significantly different. The activities of cellobiase and fl-glucosidase demonstrated a distinct maximum in September; but the highest activity of phenoloxidase appeared in February, and the lowest was in September; the highest peroxidase activity was in November; whereas there was no significant difference for chitinase activity. Correlation analysis showed that the soil water content was negatively related to the activities of phenoloxidase and peroxidase; the soil surface temperature was positive related to cellobiose activity and negative related to peroxidase activity. The contents of soil organic carbon and total nitrogen showed a significant negative correlation with β- glucosidase, and highly significant positive correlation with peroxidase. Our results suggest that the variation of different soil enzyme activity is strongly related to the change of soil water content, and the impact of soil organic carbon and nitrogen on soil enzyme activity is generally weak in lakeside wetlands.