北京东灵山地区辽东栎林种群空间分布分形分析

通过植物个体的坐标点与模拟冠幅的分形维数的分析,对辽东栎林内不同种群沿海拔梯度变化的空间分布格局和种群动态进行了比较和讨论。结果表明:模拟冠幅分形分析方法更适于分析具有大小不等、复杂多样的冠幅的植物个体空间分布格局。随着海拔的升高,不同种群的空间占据能力也随之变化。辽东栎种群的空间分布占绝对优势地位,分形维数可达1.9811;五角枫种群则逐步下降,分形维数最低为0.1170。低海拔山坡六道木种群空间占据能力较强,高海拔山坡照山白种群有较大的空间占据能力。在一定的环境条件下,不同的种群可能具有相近的空间占据能力,但对乔木层与灌木层来说,相同的分形维数的内涵是不同的。冠幅的分形维数作为表征植物种群空间占据能力的工具,是种群动态分析和种群分布格局研究的的重要指标之一。

FRACTAL ANALYSIS ON SPATIAL DISTRIBUTION PATTERNS OF POPULATION FROM QUERCUS LIAOTUNGGENSIS FOREST IN DONGLING MOUNTAIN, BEIJING CHINA

In this paper, the coordinate positions and crown breadth of plant individuals have been analyzed by using their fractal dimensions. The distributon patterns of population and population dynamic in the Quercus liaotunggensis forests at different altitudes are compared and discussed. The method of fractal analysis of simulation crown breadth is considered as a better method of studying spatial distribution of plant individuals with different and complex crown breadth. As altitude rises, the capacities of spatial occupation of different populations are variable. Q. liaotunggensis population maintains high level, with a fractal dimension reached 1.9811; Acer mono population go down with a fractal dimension is minimum, 0.1170. Whereas Abelia biflora population is strong at low altitude, Rhododendron micranthum population has stronger capacity of spatial occupation at high altitude. On the given environmental conditions, the capacity of spatial occupation of different populations become probably similar. However, the same fractal dimension between arbor and shrub layer implies different meaning. The fractal dimension of crown breadth, implying the capacity of spatial occupation of plant population, is one of the important indices in process of dynamic analysis and population distribution pattern.