苏北不同代次和林龄杨树人工林土壤酶活性季节变化特征

Seasonal dynamics characteristics of soil enzyme activities of poplar plantation with different stand ages and rotations

研究了苏北不同代次和林龄的杨树人工林土壤酶活性的季节变化特征。结果表明:不同样地土壤酶活性存在季节性差异,土壤蔗糖酶活性的季节变化表现为春夏秋相对高,冬季低;土壤脲酶活性为春季最高,夏秋冬相对低。各季节土壤磷酸酶活性从大到小为秋、夏、春、冬,过氧化氢酶季节变化不明显;表层的土壤蔗糖酶、脲酶、磷酸酶活性均高于亚表层,而过氧化氢酶变化不明显。杨树种植代次与林龄的差异对土壤酶活性产生一定的影响:一代10年生林地土壤磷酸酶、脲酶、蔗糖酶均高于对应季节二代10年生林地,一代10年生林地土壤磷酸酶、脲酶、蔗糖酶、过氧化氢酶均高于对应季节一代15年生林地土壤酶的活性。

Seasonal dynamics characteristics of soil enzyme activities of poplar plantation with different stand ages and rotations were investigated. The results showed that there exited the differences of enzyme activities of different experiment plots among spring,summer,autumn and winter. Seasonal dynamics of sucrase,urease,phosphatase and catalase were as follows： Sucrase activities of soil was higher in spring,summer and autumn than that in winter. While,urease activity of soil was higher in spring than that in summer,autumn and winter. Phosphatase activity of soil change was as autumn summer spring winter. However,catalase activity of soil was no obvious difference in the four seasons. The results also showed that,in exception of catalase,the activities of sucrase,urease,phosphatase of all soil investigated at 0- 15cm were higher than those at 15- 30 cm. There also exited difference of enzyme activities of soil in poplar plantation with different stand ages and rotations. The activities of soil phosphatase,urease and sucrase in the 10-year-old stands of the first-rotation poplar plantation were higher than those in the 10-year-old stands of the second-rotation poplar plantation in correspond with season. The activities of soil phosphatase,urease,sucrase and catalase in the 10-year-old stands of the first-rotation poplar plantation were all higher those in the 15-year-old stands of the first-rotation poplar plantation.