应用细胞自动机对一年生植物种群扩散进行理论研究

The Application of Cellular Automata to study Theoretically Annual Plant Population Dispersal

应用细胞自动机方法构造了用于研究一年生植物扩散的理论模型并应用该模型模拟了一年生植物(杂草)种群在同质环境中的扩散.一年生杂草种子的扩散距离和分布是其种群扩散的主要方式,故本文将其种子扩散分布作为构建邻域细胞函数的基础.根据Howard(1991)提供的某一年生杂草种子的扩散数据,本文导出了一个25邻的邻域细胞函数和相关的转移函数.建立了一个受控的细胞自动机模型,通过模拟,发现在同质环境中聚集在一起的一年生植物杂草越多就需要越大的控制力才能限制它们扩散;生长于农田边缘的杂草更容易被控制.这些模拟结果表明该模型能较好地表现生态学中的两个众所周知的现象;生物的聚集效应和边缘效应.希望自动机方法和在本文获得的知识将有助于我们制订植物种群的最优管理策略.

In this article,the method of cellular automata(CA)was applied to construct a theoretical model to study plant dispersal,and an annual plant(weed)dispersal in homogenous environment was simulated by using the model. Seed dispersal is a main way for annual plants to spread. Therefore the distance and distribution of dispersal of annual plant(weed)seeds are essential to construct neighborhood function. According to the data of some plant seed dispersal showed by Howard (1991)[1], the neighborhood function with 25 neighborhood cells and transition function were derived in this article.Accordingly,a controllable CA model was built.By simulating the CA model, some interesting things were discovered that in homogenous environment, the more plants (weeds) grow together, the greater control force is needed to restrict their dispersal;the plants(weeds)growing on the edge of their habitat are more easily controlled than those growing the central part of their habitat.The simulation results showed that the CA model can exhibit, in a graph, two well-known ecological phenomena: aggregation effect and edge effect.It is hoped that the CA method and the knowledge obtained in this article are helpful to make an optimal strategy of management plant(weed)population.