白玉兰在城市公园绿地群落中的根系分布

Root System Distribution of Magnolia denudata in Urban Parks Green Space Community

根系是植物生长发育的基础,构建地下根系空间分布体系是形成稳定植物群落的关键。文章选取上海闵行文化公园、共青森林公园、世纪公园内8个以白玉兰为建群树种的植物群落,采用树木雷达系统(TRU)检测群落中的白玉兰根系分布情况,同时结合群落分布、群落结构、植物生长等特征进行综合分析。结果表明:白玉兰根系数量在不同区域内的占比不相同,随土层加深呈梯度式递增,并集中分布在离主干3 m、土层深度41~70 cm处,为水平型根系。不同群落内的白玉兰根系数量存在极显著差异,其中乔灌草(M2)、乔乔(G4、G7)配置结构对白玉兰生长有利。闵行文化公园M1、共青森林公园G4、世纪公园S8群落内的白玉兰处于全光照下,其根系分布在水平方向较均匀,在垂直方向随土层深度增加均呈递增趋势,集中分布在离主干2 m、土层深度41~70 cm处;其他群落内的白玉兰受日晒方位、日照时间的影响,种植在高大乔木东南侧(M2、G7)的生长状况明显优于东侧(G5、G6)和西南侧(M3)的生长状况。因此,在设计白玉兰种植时应以乔灌草群落结构且在其西南侧配植高大乔木或建筑为宜。

Root system is the basis of plant growth and development. Creating the spatial distribution system of root system is the key to form stable community. In this study, 8 communities with Magnolia denudata as dominant species in Minhang Cultural Park, Gongqing Forest Park and Century Park are selected to detect the root system distribution of M. denudata using tree radar system(TRU), and analyze the community distribution, community structure and plant growth. The results show that the number of root is different in proportion in different areas, and shows a gradient increase with soil depth. The roots are mainly distributed in the soil 41-70 cm deep and 3 m away from the trunk. There are significant differences in the root number in different communities. The configuration structures of tree-shrub-grass(M2) and tree-tree(G4, G7) are beneficial to the growth of M. denudata. The root system under full light(M1, G4, S8) is evenly horizontally distributed, and increases with soil depth vertically, which is mainly distributed at the 41-70 cm depth and 2 m away from the trunk. M. denudata in other communities are affected by the sun direction and sunshine time. Those planted in the southeast(m2, G7) of arbors are significantly better in the growth than those in the east(G5, G6) and southwest(M3) of arbors. Therefore, at the time of designing the planting of M. denudata, it is better to plant it in the community structure of tree-shrub-grass, especially in the southwest of tall trees or buildings.