巨桉幼树器官组织中养分元素的分布与积累特点

Distribution and Accumulation of Nutrient Elements in Organic Tissue of Eucalyptus grandis Saplings

通过对林龄1a-3a巨桉幼树的器官生物量调查、器官组织中大量元素N、P、K、Ca、Mg和微量元素Fe、Zn的含量测定及其积累量的分析结果表明:大量元素总合量在各器官中的分布为干韧皮部、叶>枝、根>干木质部,微量元素主要富集于叶和根器官中;单株木器官中大量元素的累积量排序为叶>枝>干韧皮部>根或干木质部>干木质部或根,各养分元素积累量的规律不受林龄的影响,大量营养元素依次为Ca>N>K>Mg>P;微量元素累积量Fe>Zn;林龄1a-3a巨桉平均单株木大量元素累积总量分别是12.45、136.19和420.23 g/株;各养分元素的年净积累量以Ca为最大,N、K养分元素次之,Mg元素较少,P元素最小。

The biomass, macroelements （N, P, K, Ca, Mg） and microelements （Fe, Zn） contents were detected in organs of 1a-3a Eucalyptus grandis saplings, as well as their accumulated amount. Results showed that contents of nutrient elements varied greatly in different organs. Total contents of macroelements N, P, K, Ca and Mg in1a-3a E. grandis were distributed in the order of stem phloem, leaves 〉 branch- es, roots 〉 stem xylem. Accumulated amount of macroelements in 1a-3a E. grandis were in the order of leaves 〉 branches 〉 stem phloem 〉 roots or stem xylem 〉 stem xylem or roots. Accumulated amount law of nutrient elements was not affected by the plant age. Microelements Fe and Zn were mainly concentrated in the leaves and roots. The accumulation of macroelements was in the order of Ca 〉 N 〉 K 〉 Mg 〉 P; and the microelements was in the order of Fe 〉 Zn. Accumulated amounts of microelements in 1a-3a E. grandis were 12.45 136.19 and 420.23 g per plants, respectively. Among the annual net accumulated amount of nutrient ele- ments per plant in 1a-3a E. grandis, Ca element was the maximum, N and K ele- ments took the second and third places. Mg element was relatively small and P el- ement was the minimum.