秃杉人工林微量元素含量、积累与分配特征

Concentration,accumulation and distribution of microelementsin Taiwania flousiana plantation

对广西南丹山口林场3种林龄(8、14和28年生)秃杉人工林的Fe、Mn、Cu、Zn和B等5种微量元素含量、积累量、年净积累量及其分配进行了研究。结果表明:秃杉各部分微量元素含量从大到小依次为树叶、干皮、树枝、树根、干材;林木各组分微量元素含量以Mn或Fe最高,其次是Zn和B,Cu最低;8、14和28年生秃杉林分微量元素积累量为12.755～46.393kg/hm2,其中各乔木层微量元素积累量占总积累量分别为87.84%、78.96%和76.81%,林下植被层的分别占2.39%、4.01%和5.47%,凋落物层的分别占9.77%、17.03%和17.72%;秃杉人工林不同组分微量元素积累量的分配随林分年龄的增长发生变化,由8年生和14年生以在树叶和树枝中为主,逐渐转移到28年生在以干材和树皮中为主,各微量元素积累量以Fe或Mn最高,其次是Zn和B,Cu最低;3种年龄林分微量元素年净积累量分别为1.398、1.420和1.273kg/(hm2.a),同一组分各微量元素年净积累量与各组分微量元素积累量变化顺序一致,即为Mn或Fe较高,Zn次之,B和Cu较低。

The concentration, accumulation, annual net accumulations and distribution of five microelements （ Fe, Mn, Zn, Cu and B） in Taiwania flousiana plantation of three stand ages （4-year-old,7-year-old and 11-year - old） were studied in Nandan Shankou Forestry Farm in Guangxi of China.. The results showed that concentrations of these five microelements in different components of T. flousiana plantation were in the order of leave, bark, branch, root, stem. In plant, concentrations of Mn and Fe were the highest among the five elements, followed by Zn and B, while Cu was the lowest in various organs of T. flousiana plantation. The total accumulation of microelements at three stand age plantations were 12. 756 kg/hm^2 , 25. 175 kg/hm^2 and 46. 393 kg/hm^2, respectively. Of the total storage of nutrients, 76.81% -87.84% was distributed in arbor layer, 2.39% -5.47% at forest floor layer, and 9.77% -17.72% at stand litter layer. The accumulation of microelements in T. flousiana varied at different stands growth stages. Most microelements accumulated in leaves and branches at 8-year-old and 14-year-old, while they moved gradually in stem and root at 28-year-old. The accumulation of Fe or Mn was the highest, then Zn and B, and Cu the lowest. Microelement annual net accumulations in three stand ages plantation were 1. 398 kg/（ hm^2 · a） ,1. 420 kg/（ hm^2 · a） and 1.273 kg/（ hm^2 · a）, respectively. Changes in annual net accumulation of various micro-nutrients in the same component were similar to that in various components,i, e. , Mn or Fe,Zn, B, Cu.