【摘要】 利用Hegyi单木竞争指数模型对江苏镇江宝华山国家森林公园特有濒危植物宝华玉兰种内、种间竞争强度进行定量分析。结果表明:宝华玉兰竞争压力主要来自种间,占总竞争的90.7%。宝华玉兰种内竞争、种间竞争强度大小顺序为:紫楠>野核桃>建始槭>宝华玉兰种内>毛竹>化香>枫香>皂荚>朴树。整个林分竞争木对对象木的竞争强度与对象木的胸径大小近似服从幂函数关系,而伴生树种竞争木对对象木的竞争强度与对象木的胸径大小近似服从对数函数关系。种间竞争强度和对象木的胸径大小呈显著负相关。利用模型预测,当宝华玉兰的胸径达到30cm后,竞争强度几乎没有变化。研究认为,将无性系分株换算为一株与其胸高断面积之和相等的个体更为合理。更多还原

【Abstract】 By using Hegyi’s single-tree competition index model,the intra-and interspecific competition intensities of endemic and endangered plant Magnolia zenii from Baohuashan National Forest Park in Zhenjiang City of Jiangsu Province were quantitatively analyzed,with the methods suitable for treating the surveyed data of clonal ramet discussed. The main competitive stress to the M. zenii population came from interspecific competition,which accounted for 90.7% of the total. The competition intensity of interspecific competition with M. zenii followed the order of Phoebe sheareri>Acer henryi>Juglans cathayensis>M. zenii>Phyllostachys heterocycla>Platycarya strobilacea>Liquidambar formosana>Gleditsia sinensis>Celtis sinensis. The relationship of the competition intensity between competitive trees and objective trees in the whole forest with the DBH of objective trees nearly conformed to power function,while that between other competitive and objective trees with the DBH of objective trees conformed to logarithm function. There was a significant negative correlation between the whole forest competition intensity and the DBH of objective trees. The predicated results showed that when the DBH of M. zenii reached 30 cm,the change in competition intensity was very small. As for clonal ramet,it was suggested that the method of taking the summation of basal areas at breast height of a species’ clonal ramet cluster as the equal area of single tree of the same species was more reasonable.更多还原