采伐干扰对巨桉人工林土壤养分和酶活性的影响

研究了巨桉二代萌生林土壤水热条件、养分状况和酶活性。结果表明,与巨桉人工林比较,采伐后的巨桉二代萌生林地E1和E2的土壤含水量增加,0～20cm土壤温度升高,土壤有机质、碱解N、蔗糖酶、脲酶、磷酸酶和过氧化氢酶活性均提高,但有效P含量减少,pH值减低,土壤酸性增强。保留采伐剩余物的样地E1,其土壤含水量、有机质、水解N、有效P和蔗糖酶含量高于E2,分别高12.77%、25.27%、11.82%、6.25%和22.26%,脲酶、磷酸酶和过氧化氢酶活性略高于E2。从现目前研究结果看,采伐干扰有利于改善林地水热条件,提高土壤酶活性,加速养分循环,尤其以保留采伐剩余物的效果为好。

Effects of Harvesting on Soil Nutrients and Enzyme Activities in Eucalyptus grandis Plantation

The study on soil hydrothermal condition,nutrient status and enzyme activities of the secondary coppice forest of Eucalyptus grandis plantation showed that compared with Eucalyptus grandis plantation,in the secondary coppice forest—— E1 and E2,the soil moisture increased,the temperature of soil from 0 to 20 cm rose,and soil organic matters,alkalize N,urease,posphatase and catalase all were enhanced.But available P decreased,pH value reduced and soil acidity was strengthened.The contents of soil organic matter,alkalize N,available P and sucrase activity of E1 that reserved logging wastes were 12.77%,25.27%,11.82%,6.25% and 22.26% higher than E2 respectively.Urease activity,posphatase activity and catalase activity of E1 were slightly higher than those of E2.The results explained that harvesting,especially that of reserving logging wastes,was helpful to improve soil hydrothermal condition,elevate soil enzyme acivities and accelerate nutrient cycling.