【摘要】 用标准地 标准木 分层分割法测定了华北落叶松 (Larixprincipis rupprechtiiMayr)树干主要营养元素的分布规律 ,结果为 :树干木质部水平方向N、P、K质量分数随年龄增加逐渐增大 ,Ca、Mg的逐渐减少。树干木质部垂直方向N、P、K质量分数随圆盘高度增加而增加 ,Ca、Mg变化较小。树皮N、P、K、Mg质量分数随圆盘高度的增加而增大 ,Ca有减小的趋势 ,但梢部质量分数较高 ;树干主要营养元素的质量分数大小排序为 :K >Ca >N >Mg >P。不同个体不同组分质量分数之比分别为 ,皮 /木N :4 1～ 6 3,P :2 8～ 4 8,K :2 1～ 2 7,Ca :2 3～ 4 1,Mg :2 1～ 3 1;皮 /心 ,N :4 9～ 8 6,P :5 2～ 7 5,K :2 2～ 2 7,Ca :2 6～3 8,Mg :2 0～ 3 2 ;边 /心 ,N :1 2～ 1 8,P :1 8～ 2 3,K :1 1～ 1 4 ,Ca :0 7～ 0 8,Mg :0 9～ 1 1。树干主要营养元素运输趋势为 :N、P、K由心材向边材 ,由干基向梢部 ,Ca、Mg由边材向心材 ,且K、Ca、Mg变化梯度较小 ,N、P变化梯度较大 ,质量分数较低。测定树干主要营养元素质量分数的最佳取样部位在树高的 3/10～ 5/10处。更多还原

【Abstract】 By standard area\|standard trees\|stratification and chemical analysis, main nutrient distribution in bole of North China larch has been determined, the results as follows: N, P and K percentage contents in xylum of bole at vertical direction increase with age, but decrease Ca and Mg N, P and K percentage contents in xylum of bole at vertical direction increase with disc height, but do not markedly change Ca and Mg N, P, K and Mg percentage contents in bole bark increase with disc height, but decreases Ca and reaches at summit at tip The main nutrient elements put in order as K>Ca>N>Mg>P The N, P, K, Ca and Mg ratio between bole bark and xylum are 4 1～6 3, 2 8～4 8, 2 1～2 7, 2 3～4 1 and 2 1～3 1 respectively The N, P, K, Ca and Mg ratio between bole bark and heartwood are 4 9～8 6, 5 2～7 5, 2 2～2 7, 2 6～3 8 and 2 0～3 2 respectively The N, P, K, Ca and Mg ratio between sapwood and heartwood are 1 2～1 8, 1 8～2 3, 1 1～1 4, 0 7～0 8 and 0 9～1 1 respectively The N, P and K move from heartwood to sapwood and from base to tip, but Ca and Mg do from sapwood to heartwood There are not notedly difference for main nutrient elements among individuals The optimum sampling position to research bole nutrient is 3/10～5/10 of tree height更多还原