摘要
对湘南低山丘岗区密度为 90 0、1 1 2 5和 1 5 0 0株 /hm2 的 6年生巨尾桉 (Eucalyptusgrandis× urophglla)丰产示范林营养元素积累、分布和生物循环进行了研究。结果表明 :不同组分的营养元素含量差异较大 ,以树叶营养元素含量最高 ,树干最低。各组分中大量元素以 K和 N的含量最高 ,P的含量最低。微量元素以 Mn、Fe的含量高 ,Cu最低。单株林木营养元素积累量随林分密度的增加而明显减小 ,低密度林分是高密度林分的 1 .44倍 ,不同组分营养元素积累量的多少不受林分密度制约 ,单株林木各种营养元素积累量依次为 :Ca>K>N>Mg>P>Mn>Fe>Zn>Cu;林分营养元素积累量随林分密度的增加而增加 ;乔木层营养元素积累量占整个林分养分总积累量的 75 .3 %以上。在草本层各种不同密度林分均以 N素积累量最高 ,K、Ca较高 ,Cu的积累量最低。年净积累量随林分密度的增加而提高。 3种密度林分年净积累量分别达到 2 3 9.45 48、2 64 .1 1 48和 2 70 .2 64 8kg/(hm2 · a) ,大量元素占总量的 95 .2 0 %以上。各种元素的年净积累量以 Ca为最大 ,占 41 .0 8%～ 41 .42 % ;Cu的年净积累量最小 ,仅占 0 .66%。林分大量元素的吸收量达 3 5 1 .1 961～ 3 73 .7767kg/(km2·a) ;微量元素的吸收量达 1 5 .95 49～ 1 8.9697kg/(hm2·
The accumulation,distribution and biocycle of nutrients of 6 - years Eucalyptus grandis× urophglla high yield exemplary forest with the densities of90 0 ,1 1 2 5 ,and1 5 0 0 trees/hm2 were studied in the low hilly area of south Hunan.The results showed that the nutrientcontents were differentin various components,highestin the leaves and lowest in the stems.The contents of K and N were the highest,and those of P were the lowest in macro- elements,and Mn and Fe were the highest and Cu was lowest in mi- croelements.Nutrientaccumulation ofsingle tree decreased distinctly with the increase ofthe standing den- sity,and that of single tree of the low density stand was1 .44times as those with high densities.Other- wise,the high orlow ofnutrientaccumulation quantity were notconditioned by standing density in variable components.The nutrients accumulation ofsingle tree were reduced in abundance in turn:Ca>K>N>Mg >P>Mn>Fe>Zn>Cu.The standing nutrient accumulation raised with the increase of the standing den- sity.Nutrient accumulation quantities of arbor layer were over75 .3 % in total those of the stands.The ac- cumulation of N was the highest,then the K and Ca,and Cu the lowest.Annual net accumulation raised with the increase of the standing density and reached 2 3 9.45 4 8,2 6 4 .1 1 48and 2 70 .2 6 4 8kg/(hm2 · a) with the three densities,respectively,and thatofmacro- elements were over95 .2 0 % in total those ofthe stands. Annual net accumulation of Ca the highest,accounting for 41 .0 8%～ 41 .42 % of all elements,and that of Cu was lowest,accounting for0 .6 6 % .The absorption ofmacro- elements reached3 5 1 .1 96 1～ 3 73 .776 7kg/ (hm2 · a) in the stands,that of microelements 1 5 .95 4 9～ 1 8.96 97kg/ (hm2 · a) ,which was highest in the stand with medium density.The absorption of nutrient elements were ranked in turn:Ca>K>N>Mg>P >Mn>Fe>Zn>Cu.The restitution of macro- elements reached1 2 4 .86 4 0 kg/ (hm2 · a) ,occurring in the stand with low density,and that of microelements reached6 .70 9
出处
《生态学报》
CAS
CSCD
北大核心
2001年第10期1734-1740,共7页
Acta Ecologica Sinica
基金
国家自然科学重大基金 (编号 :3 98993 70 )
中国科学院知识创新项目 (编号 :KZCX2 -40 7)
国家"九五"林业科技攻关研究 (编号 :96-0 1 1 -0 1 -0 3 )资助项目
关键词
巨尾桉人工林
营养元素
生物循环
林分密度
Eucalyptusgrandis× urophglla plantation
nutrient element
biocycle
standing density
