无瓣海桑人工林树冠结构的分形分析

摘要

Based on the artificial Sonneratia apetala forest of different ages in Fucheng, Leizhou, the fractal characteristics and twig distribution patterns were analyzed by means of box-counting dimension. The results showed that the fractal dimension of S. apetala was 1.470 6, thus revealing the canopy complexity of 5. apetala and its strong ability to occupy and utilize the ecological space. There was difference in the ability to use the space of canopy and twigs of different ages. The fractal dimension was between 1.20 -1.80,while that of a single lateral branch layer was between 1.30-1.65, which was similar to fractal dimension of the canopy .showing the self-similarity of fractal features of canopy. So far as different tide directions and lateral branch distribution of canopy were concerned, more lateral branches were distributed in the direction towards tides than those in the opposite direction. The fractal dimension of lateral branches of the No. 1 canopy was 2.004 9, and that of the No. 2 canopy was 1.5007, thus indicating the stronger ability and competitiveness in the distribution occupation of the lateral branches of the upper canopy.%采用计盒维数对广东省雷州市附城镇不同年龄的无瓣海桑人工林的分形特征及侧枝分布格局进行分析.结果表明,无瓣海桑树冠有较强的占据与利用生态空间的能力,分形维数为1.470 6;不同年龄无瓣海桑的树冠及分枝结构利用生态空间的能力均存在差异,不同树龄树冠的分形维数介于1.20 - 1.80之间,单个侧枝层面的分形维数介于1.30-1.65之间,接近于树冠的分形维数,表现树冠的自相似性的分形特征;从不同潮向及冠层来看,迎潮面的侧枝分布数量比背潮面的多,而位于树冠顶部的1号冠层侧枝的分形维数(2.0049)比位于树冠基部的2号冠层(1.500 7)大,表明上层树冠的侧枝分布占据力和竞争力更强.