利用林木位置圖探討孔隙對林木生長之影響

Using Individual Tree Location Map to Explore Gap Influence on Tree Growth

本研究的目的是以馮、李（2000）GIS 方法繪製不同密度的柳杉永久樣區之林木位置圖，配合胸高直徑──樹冠迴歸式繪製樹冠投影圖，觀察其孔隙變化情形，並嘗試由Schnute 單株生長模式及其參數變化來探討孔隙對林木生長產生的影響。結果顯示，孔隙變化愈大，其生長潛力愈強及其參數變化愈大，建議無論林分生長模式與單株林木生長模式，宜加入表示孔隙的參數。 In the study, the tree location map of 5 different density of permanent sampling plots (PSPs) in Cryptomerria japonica were made with the GIS approach of Feng & Lee (2000) at first. Then, tree crown closure maps were made to investigate the gap change in different ages. The parameters of Schnute individual tree growth models were used to explore the change of gap influence upon the tree growth. The results showed that the wider the gap, the larger carrying capacity of the growth and parameters of the Shnute model. The gap variables were suggested to put in the stand growth model and individual tree growth model for estimating efficiently.

In the study, the tree location map of 5 different density of permanent sampling plots (PSPs) in Cryptomerria japonica were made with the GIS approach of Feng & Lee (2000) at first. Then, tree crown closure maps were made to investigate the gap change in different ages. The parameters of Schnute individual tree growth models were used to explore the change of gap influence upon the tree growth. The results showed that the wider the gap, the larger carrying capacity of the growth and parameters of the Shnute model. The gap variables were suggested to put in the stand growth model and individual tree growth model for estimating efficiently.