桤木人工林细根与土壤养分含量季节动态变化

对桤木人工林细根、土壤养分含量的季节变化及其两者之间的关系进行了研究.结果表明:(1)桤木细根中大量元素N、Ca、K、Mg、P含量冬季高,春季最低;微量元素Fe、Mn、Zn、Cu、Pb、Ni、Cd含量冬季最低,春夏季较高.(2)土壤各层中大量元素N、Ca、K、Mg、P含量冬季最低,夏季最高;微量元素Mn、Zn含量在冬季最低,秋季最高;Fe、Ni、Pb、Cu、Cd含量在冬季最高,春秋较低.(3)细根和土壤中大量元素含量在冬季存在负相关关系,微量元素Fe、Ni、Cd含量在一年四季均存在显著负相关关系,Mn、Cu含量在春季、夏季和秋季存在负相关关系,Zn、Pb含量在春季、夏季和秋季存在正相关关系.

Seasonal Dynamic Variation of Nutrient Elements From the Roots and Soil of Alnus cremastogyme Burk Plantations

This paper made a dynamic study of the seasonal variation of nutrient elements in the fine roots and soil from Alnus cremastogyme Burk plantations,and of the relationship between them.Results show that:(1) the contents of N,Ca,K,Mg and P in the roots are the highest in winter but lowest in spring and the contents of Fe,Zn,Cu,Pb,Ni and Cd are the lowest in winter but rather high in spring and summer;(2) the contents of N,Ca,K,Mg and P in the soil are the lowest in winter but highest in summer,the contents of micronutrients Mn and Zn are the lowest in winter but highest in autumn and the contents of micronutrients Fe,Ni,Pb,Cu and Cd are the highest in winter but rather low in spring;(3) a negative correlation is found in winter between the contents of nutrients in the roots and those in the soil;and(4) of micronutrients,the annual variation of Fe,Ni and Cd has a significantly negative correlation but the seasonal variation of Mn,Cu,Zn and Pb only displays a significantly positive correlation in spring,summer and autumn.