Abstract: The study of differences in root structure characteristics between Phyllostachys edulis and P. praecox forests through measurements of length, volume, surface area, and dry weight of the root was carried out, which provided a basis for bamboo resource cultivation, soil management and enhancing the economic benefits of bamboo forests. The soil distribution characteristics of bamboo forest roots were investigated by using the methods of root digging scanning. P. edulis roots mainly distributed in the soil layer of 0-40 cm, and the root surface area, volume, length and dry mass accounted for more than 80% of the total root system. The proportions of root length and volume of different diameter classes in P. edulis and P. praecox forests showed the decreasing trend with the deepening of the soil layer. In the different diameter classes of P. edulis roots, roots with diameters＜1 mm had the highest proportion of length (70.45%), whereas those with diameters＞2 mm had the highest proportion of volume (78.73%). In P. praecox forest, the roots were distributed only in the soil layer of 0-40 cm, and the root volume, surface area, and dry weight accounted for more than 60% in the surface soil layer (0-20 cm). The root length accounted for 59.39% of the total length, and roots with diameters＜1 mm had the highest proportion of length (80.46%) among different diameter classes, though they had the smallest proportion of volume (16.63%). In the soil layer of 0-40 cm, the proportion of root length in three diameter classes showed that P. praecox forest was greater than P. edulis forest. The proportion of roots with diameters≤2 mm showed that P. edulis forest was less than P. praecox forest. The proportion of roots with diameters＞2 mm in P. edulis forest was greater than P. praecox forest. The soil layer of 0-40 cm is the main active layer for the growth of bamboo forest roots, and it is also the important level for soil management in bamboo forests. P. edulis and P. praecox differ significantly in root content and structure. P. edulis has the larger root structure compared to P. praecox. Therefore, it is necessary to propose measures that are more suitable for bamboo management by combining different root structure characteristics.

Key words: Phyllostachys edulis, Phyllostachys praecox, root, root structure

摘要： 通过探究毛竹Phyllostachys edulis和雷竹P. praecox竹林根系长度、体积、表面积及干质量等各项数量指标，阐明两类竹林根系结构特征及其差异，为竹类资源培育、竹林土壤管理以及竹林经济效益提升提供依据。采用根系挖掘法和根系扫描法，布设样地，对竹林根系在土壤中的分布特征进行研究。结果表明，毛竹林根系主要分布在0～40 cm土层，根系表面积、体积、长度及干质量占全部根系比重均达80%以上。毛竹林和雷竹林内不同径级的根系长度和体积所占全部的比例均随着土层的加深呈逐渐降低趋势。毛竹林不同径级根系分布中，＜1 mm根系长度占比最大(70.45%)，＞2 mm根系体积占比最大(78.73%)。雷竹林根系仅分布在0～40 cm土层，且土壤表层(0～20 cm)内根系体积、表面积及干质量占比均超60%，根系长度占总长度59.39%，不同径级分布中＜1 mm径级根系长度占比最大(80.46%)，但体积中占比最小(16.63%)。土壤0～40 cm土层内，3个径级根系长度占全部根系长度比重均表现为雷竹林＞毛竹林，≤2 mm径级根系体积占比均表现为毛竹林＜雷竹林，＞2 mm径级中毛竹林＞雷竹林。土壤层0～40 cm是竹林根系主要生长发育的活动层，亦是竹林土壤管理的重要层次，而毛竹林和雷竹林根系含量及结构存在明显差异，毛竹林相比雷竹林具有更庞大的根系结构。结合不同根系结构特征提出更符合竹种经营管理的措施是必要的。

关键词: 毛竹, 雷竹, 根系, 根系结构