尾巨桉人工幼林营养元素的生物循环

Biological Cycling of Nutrient Elements in Young Eucalyptus urophylla×E.grandis Plantation

[目的]为尾巨桉人工林的营养管理提供科学依据。[方法]采用标准样地法研究尾巨桉人工幼林(2年生)的N、P、K、Ca、Mg、Fe、Mn、Zn、Cu含量、积累量和生物循环特点。[结果]尾巨桉不同器官营养元素含量依次为树叶>干皮>树枝>树根>树干;各器官中大量营养元素以N含量最高,其次为Ca或K,P含量最低,微量元素Mn、Fe含量最高,其次为Zn,Cu含量最低;不同器官营养元素贮存量依次为干材>树枝>树根>干皮>树叶;林分对养分的年吸收量、归还量和存留量分别为233.88、70.28、163.60 kg/(hm2.年),利用系数为0.71,循环系数为0.30,周转期为4.66年。[结论]尾巨桉对营养元素的利用率较高,归还速率较慢,周转期较长。

[ Objective ] The study was to provide the scientific basis for nutrition management of Eucalyptus urophylla x E. grandis plantation. [ Method] Standard plot method was taken to study the content, accumulation, biological cycling characteristics of N, P, K, Ca, Mg, Fe, Mn, Z, Cu in 2 yeas old young E. urophylla x E. grandis plantation. [ Result] Nutrient elements content in different organs of E. urophylla × E. grand/s from big to small in order was leaves 〉 bark 〉 branch 〉 root 〉 stem. Among the macronutrient, N content in each organ was the highest, and the following was those of Ca or K, P content was the lowest. Among the trace elements, Mn and Fe contents in each organ were the highest, and the following was that of Zn, Cu content was the lowest. The storage amount of nutrient elements in different organs from big to small in order was stem 〉 branch 〉 root 〉 bark 〉 leaves. The uptake, return amount and retention of forest on nutrient were 233.88, 70.28, 163.60 kg/ （hm2 · a） resp. with productivity of 0.71, cycle coefficient of 0.30 and turnover period of 4.66 a. [ Conclusion ] The utilization ratio of E. urophylla × E. grandis on nutrient elements was higher with the lower returning rate and the longer turnover period.