Abstract: Fractal theory is an important branch of nonlinear science and a useful means of investigative research.The introduction of fractal theory may provide a new perspective for explaining and resolving some complicated problems in the field of Grassland Science.As examples,the fractal dimension of grass root can reflect the branch structure;the fractal features of soil are highly relevant to vegetation recovery (or deterioration),soil texture,and physicochemical properties;fractal study on patches reveals that fractal dimension is an important indicator of landscape fragmentation and pattern,as well as evolution in landscapes;at the same time,fractal can reflect the spatial distribution pattern of community diversity and evenness to a greater extent than other methods and effectively analyze the scale dependence problem;the application of fractal theory in remote sensing information collection and image processing can improve accuracy;and the dimensions of food-seeking route and vegetation spatial structure help to identify grazing animal activities and grasslands’ carrying capacity,which can enhance the sustainable utilization of grasslands.In spite of this,most existing researches remain within the calculation of fractal indexes and lack practical applications.Thus breaking through purely theoretical studies to explore the applications of fractal-based cellular automata simulations of barren patch dynamics and the comprehensive integration of fractal theory are emerging as a new field of study.

Key words: Fractal theory, Fractal dimension, Grassland Science, Application

摘要： 分形理论是非线性科学的一个重要分支,是科学研究中一种重要的数学工具和手段,分形理论的引入给解释和解决草地科学领域出现的一些复杂问题提供了一种新的思路和方法。其中根系形态的分形维数能反映根系的分支结构;土壤的分形与植被恢复年限(或退化程度)、土壤质地、土壤理化性质有密切关系;斑块的分形是景观破碎化和景观格局的重要指标,可以解译斑块演替过程;同时,分形能较好地反映群落多样性和均匀度的空间分布格局,有效分析尺度依赖问题;遥感信息的收集和遥感图像处理应用分形理论可提高精度;此外,根据动物觅食路径的分维和植被空间结构的分维来确定动物活动和载畜量可以提高草地利用率。然而,有关分形在草地科学中的应用研究多停留在分形指标的计算上且实用性较差,实践探索基于分形的元胞自动机来模拟三江源区草地秃斑块动态的真实性与准确性及分形理论综合集成研究或将成为草地科学新的研究领域。

关键词: 分形理论, 分形维数, 草地科学, 应用