桂西北秃杉人工林土壤肥力变化的研究

Soil Fertility Change in Taiwania flousiana Plantation in Northwest Guangxi

采用时空互换法,于广西南丹县山口林场选取不同林龄(9、14、20 a)的秃杉人工林作为研究对象,对其土壤物理性质、化学性质和生物化学性质(土壤酶活性)进行研究。结果表明:不同林分年龄土壤性质存在一定的差异,8、14、20 a秃杉人工林表层土壤(0 20 cm)土壤密度分别为0.978、0.914、0.890 g·cm-3,总孔隙度分别为63.10%、65.53%、66.40%,土壤最大持水量分别为64.55%、71.70%、74.58%。随着林龄的增长,土壤各化学和生物化学指标的变化不尽相同,但林分年龄到20年生时,多数土壤养分和酶活性指标都有所升高,土壤肥力状况得到提高。

Taiwaniaflousiana plantations with different stand ages （9-, 14- and 20-year-old） in Nandan Shankou Forest Farm of Guangxi were selected to study the soil physical and chemical properties and enzyme activities by spacial-temporal exchange method. The results showed that there existed differences in the soil physical and chemical properties and enzyme activities among the 3 age classes of T. flousiana plantations. The surface soil （0 -20 cm）density, total porosity and maximum moisture capacity were 0. 978 g·cm-3, 63.10% and 64.55% in 8-year- old T. flousiana plantation; 0.914 g · cm-3, 65.53% and 71.70% in 14-year-old T. flousiana plantation; and 0. 890 g ·cm-3, 66.40% and 74.58 in 20-year-old T. flousiana plantation. With the increase of stand age, the changes of soil chemical and biochemical indicators were not the same, but to 20-year-old forest period, most soil nutrient and enzyme activity index increased, the soil fertility conditions improved.