【摘要】 对湘南低山丘岗区林分密度为 90 0 ,112 5和 15 0 0株· hm- 2 的 6年生巨尾桉 Eucalyptusgrandis× urophglla丰产示范林进行了生物量及生产力的测定分析 .结果表明 :单株生物量随密度的增加而明显减小 ,低密度林分是高密度林分的 1.48倍 ;林分生物量随密度的增加而增加 ,高密度林分比低密度林分高出 16.82 t· hm- 2 .年均净生物量高于杉木中心产区杉木人工林的水平 ,分别达到 2 2 .5 7,2 4.85和 2 5 .3 7t· hm- 2 a- 1 .林分各组分的生物量随密度的增大而增大 ,并出现 W干 >W根 >W枝 >W皮 >W叶 >W果 的规律 .林分结构以中密度林分合理 ,叶面积指数最高 ,干材生物量达 63 %以上 .在湘南低山丘岗区发展潜力大 ,可作为短周期工业用材林培育首选树种更多还原

【Abstract】 The biomass and productivity of 6 year old Eucalyptus grandis×urophglla high yield demonstration forest with densities of 900, 1 125, and 1 500 trees·hm -2 were investigated in the low hilly area of Southern part of Hunan. The results showed that the biomass of individual tree decreased distinctly with the increase of the density,and that of the low density stand was 1.48 times as much as that of high density stand.While the biomass of the stand increased with the increase of the density, and the stands with high and densities were 16.82 and 13.72 t·hm -2 higher than that with low density. The annual net biomass reached 22.57, 24.85, and 25.37 t·hm -2 , respectively, which was higher than that of Chinese fir plantation in key areas. The component biomass of the stand increased with the increase of density, which exhibited the patterns of W stem > W root > W branch > W bark > W leaf > W fruit . The stand with middle density was observed as a reasonable stand structure in which the index of the leaf area was the highest and the stem biomass reached more than 63%. It was concluded that Eucalyptus grandis×urophglla used for wood pulp had a great potentiality to develop in the low hilly areas of Southern part of Hunan, and it could be used as the choice for short term industrial species.更多还原