5年生锯叶棕生长情况调查分析

锯叶棕是美国东南部常见的一种棕榈科珍贵药用植物，国家林业局桉树研究开发中心从美国佛罗里达州引进了锯叶棕的优质种源后，定期对其树高、地径、冠幅、分株等生长情况进行调查。结果发现：5年生锯叶棕总体生长缓慢，但分株能力强。从树高、地径等指标来看，前2a生长最快，3~4a生长缓慢，第5a生长又出现变快趋势。5 a后锯叶棕最多可由1株分株为16株，树高最高为262 cm，地径最大为28 mm，冠幅最大为420 cm。锯叶棕生长差异性较大，最小的锯叶棕树高仅为97 cm，地径为8 cm。

Investigation and Analysisof GrowthofSerenoa repensto Age Five Years

SerenoaRepensis one of the more common palmae plants in southeastern United States of America. China Eucalypt Research Centre introducedS. repensseed from the state of Florida for planting, and 32 trees ofS. repens’s were evaluated for tree height, ground diameter,crown width, and suckering up to age five years. The results showed：S. repensgrew slowly but had abundant suckering. The height and ground diameter grew fastest in the first two years and growth slowed during the third and fourth years, but then increased in the fifth year. At age five years, maximum tree height was 262 cm, maximum ground diameter was 28 cm and maximum crown width was 420 cm. However, there were large significant differences among the growth of the individualS. repenstrees, and the smallest tree was only 97 cm tall with a ground diameter of only 8 cm.