杉木人工林间伐后林下植被养分动态的研究 Ⅱ.土壤营养元素含量的变化与植物的富集系数

杉木人工林间伐后，掌握其土壤营养元素含量的变化情况及植物的富集系数对促进人工林养分良性循环和维护林地生产力具有重要意义．采用定位研究方法，分析了会同县杉木人工林间伐区和对照区土壤营养元素含量．结果表明：间伐区土壤中大量营养元素含量由对照区的３０．０８ｇ／ｋｇ降为２７．５０ｇ／ｋｇ，下降９．３８％，微量元素含量变化不大，但因间伐后林下植被大量增加，它们对补充林地养分和养分的生物循环具有积极意义；植物种类不同，其富集系数则不同，就是同一植物，它对各元素的富集系数也是不同的．

Nutrient Study of Understory Vegetation in the Thinned Chinese Fir Plantation II.Contents of nutrient in the soil and accumulation index of plants to the soil

To enhance the nutrient biological cycling and restore the forest site quality, it is important to know the change of nutrient contents in the soil and the accumulation index of plants to the soil in a thinned Chinese fir plantation. The nutrient contents in the soil of a thinned Chinese fir plot and that in a control one are analyzed in this paper. The results show that the contents of macro elements in the soil of a thinned stand decreased by 9.38% ,from 30.08 g/kg (in the control plot) to 27.50 g/kg, while those of micro elements have little change, and the growth of understory vegetation in the thinned stand plays a great role in adding the soil nutrient and enhancing the nutrient biological cycling. The accumulation index of plants to the soil differs in different species and also in the same species for different elements.