【摘要】 传统的炼山、大穴造林方式易引桉树人工林起水土流失、地力下降等一系列问题，免炼山、免挖穴、简力定植可能是解决上述问题的重要手段。文章以尾巨桉为研究对象，布置了桉树免炼山、免挖穴、简力定植方式并以大穴造林为对照，探讨两种方式对桉树人工林根系与蓄积量的影响。结果表明：造林5年后两种造林方式桉树人工林的根系主要分布范围在土层0～70 cm且根系数量多分布于土层20～50 cm，两种造林方式间差异不显著。造林后前2年，简力定植区的桉树胸径、树高与蓄积量略低于对照区但差异不显著；造林3年后逐渐反超，至第五年简力定植区桉树胸径、树高、蓄积量相较于对照区分别增长4.90%、5.13%、15.00%。简力定植造林未对林木蓄积量产生不良影响，反而提高了林木的生长量，对解决桉树人工林地力下降等问题具有较好的效果。更多还原

【Abstract】 Traditional afforestation involving hillside burning and large pit cultivation of planting spots can cause a series of problems in eucalypt plantations, such as soil erosion and declining fertility. The method of no hillside burning, no digging pits and simple planting may be important methods to alleviate the above problems. Eucalyptus urophylla × E.grandis was taken as the study object and trials were established to investigate the impact of the two afforestation methods on subsequent root system development and tree growth. At five years after afforestation, the primary distribution range of eucalypt root systems was in 0 ～ 70 cm deep soil layer, with a higher concentration of roots at depths of 20 ～ 50 cm. There were no significant differences between the two afforestation patterns studied. In the first two years after afforestation, tree diameter at breast height(DBH), tree height, and accumulation in simple planting areas were slightly lower than those in traditional afforestation areas but not significantly so. However, three years after afforestation there was a reversal of the growth advantage. By year five after afforestation, simple afforestation method showed an increase in plantation DBH of 4.90%, tree height of 5.13%, and tree volume of 15.00% over the traditional afforestation plantation. Simple planting afforestation did not have adverse effects on tree volume, but increased the growth of trees,and had a good effect on solving the problems such as fertility decline of eucalypt plantations.更多还原