林分因子的Granger因果关系研究

Study on the Granger causality of stand factors

应用协整理论,分析了胸径、树高、密度之间的Granger因果关系。滞后阶数为1时,胸径和树高互为Granger原因,这从理论上证明建立胸径和树高模型和密度管理曲线是合理的。当滞后阶数为2时,密度是胸径、树高的Granger原因,树高是胸径的Granger原因,胸径不再是树高的Granger原因,说明胸径、树高、密度3个林分因子中,密度、树高的影响更深远,所以在森林培养时,一方面要更加注意林分密度,优化林木的营养空间,促进林木因子的全面生长,另一方面,也不能忽视对树高的培养,以维持树高对胸径的影响。

The diameter at breast height, the tree height and density belong to Granger causality each other when lagging number equates 1. It is logicat to build density management curve and the models between the diameter and height for the reason. The density is Granger of height and breast diameter, and the heightis Granger causality of the diameter too, but the dihmeter isn＇t the causality of the height when logging number equates 2. In the intercomparison of effects of the diameter, height and density each other, the effect of the height and density is far-reaching. The height and density should be paid more attention for maintaining its＇ effect on the diameter in forest management.