熵值计算及其在森林生物量分布中的应用

Entropy calculation and its application in forest biomass distribution

该文对熵的概念及熵值测度方法进行了研究,并对森林生态系统作为典型的耗散自组织系统、非平衡系统进行论述。以森林生物量分布为基础,利用熵差原理计算了华北土石山区森林生物量分布熵值,并分析了其值随林分生长及选取尺度增大的变化规律。结果表明,各标准地生物量分布熵值随着选取尺度的变大而变大;在2m×2m以及5m×5m的尺度上,人工林和天然林生物量分布熵值随林分生长有着不同的变化趋势,人工林生物量分布熵值有逐渐减小的趋势,而天然林生物量分布熵值有逐渐增大的趋势;在10m×10m的尺度上,人工林变化并无规律,而天然林生物量分布熵值随林分生长逐渐增大。随着时间的推移,人工林林木不断分化,天然林生物量分布变得逐渐均匀,天然林和人工林生物量分布有趋向于统一的趋势。

The concept and the measure methods of entropy were studied,and the forest ecosystem as a typical self-organized structure system with non-equilibrium and dissipated features was concluded.Based on forest biomass distribution,the entropy difference was used to calcuate the forest biomass distribution cntropy in soil-rock mountain area of North China,and the law that the value increases with forest growth and the increasing scales was analyzed.The results indicate that:the biomass distribution entropy became bigger with the increasing scale;the biomass distribution entropy of natural forest and plantation had different trends with forest growth in minor scales(2 m×2 m and 5 m×5 m):it decreased in plantation and increased in natural forest;the natural forest entropy had no rule in a large scale(10 m×10 m),while the plantation biomass distribution entropy decreased with forest growth.For plantation varies and natural forest becomes uniform with time,the biomass distribution of them will tend to be nearly the same.