南仁山次生林樹冠層之空間異質性

Spatial Heterogeneity of Tree Crown in Nanjenshan Secondary Forest

本研究以南仁山次生林為範圍，利用克利金模式之半變異圖，模擬不同冠層之樹高與胸徑之空間分布，結果顯示指數模式之模擬效果最佳，各不同冠層之半變異圖模式參數，可供為立木屬性空間分布狀態之解釋變量。另本研究逢機選取不同徑級之立木，進行樹冠幅量測並利用迴歸分析，建立以胸徑為獨立變數之樹冠直徑推估模式，利用立木位置之胸徑空間資料，建立樹冠投影圖，並以Pearson卡方值檢定向風林型與背風林型樹冠覆蓋度之差異性，結果顯示上層立木之樹冠覆蓋度差異不顯著，而中、下層立木覆蓋度則呈現顯著性差異，顯現強勁東北季風對上層立木樹冠覆蓋度，產生一致性的影響，造成冠層結構破碎，而中下層立木樹冠覆蓋度，在地形與上層立木的雙重的保護下，其樹冠覆蓋度具有顯著性差異。 This research examined the effects of the northeast monsoon on secondary forest andthe impacts of spatial variables on stand structures. The research applied the Kriging Semi-variogrammodel to simulate Nanjenshan Secondary Forest with respect to different canopy layers and the spatialdistribution of stand diameter at breast height. It was found that simulation by exponential modelproduced the best result, where the Semi-variogram model parameters for each layer provided commentvariables for the stand attribute spatial distribution. This research also conducted random samplingof stand diameter classes, measured canopy diameters, and applied regression analysis, where thestand diameter at breast height was treated as an independent variable, to establish a canopy diametersimulation model. The stand position and corresponding spatial data on diameter at breast height wereused to generate a canopy distribution map. A Pearson Chi-square Test survey on the variations incanopy cover density between windward and leeward forest types revealed that while there was only a minor difference in the upper layer canopy cover density, it was not the case for the middle andlower layers. The result showed that the strong northeast monsoon, which destroys canopy structures,has a uniform effect on the upper layer canopy cover density. As the middle and lower stand layersare protected by the terrain and the upper stand layer, their canopy cover densities are notably different.

This research examined the effects of the northeast monsoon on secondary forest andthe impacts of spatial variables on stand structures. The research applied the Kriging Semi-variogrammodel to simulate Nanjenshan Secondary Forest with respect to different canopy layers and the spatialdistribution of stand diameter at breast height. It was found that simulation by exponential modelproduced the best result, where the Semi-variogram model parameters for each layer provided commentvariables for the stand attribute spatial distribution. This research also conducted random samplingof stand diameter classes, measured canopy diameters, and applied regression analysis, where thestand diameter at breast height was treated as an independent variable, to establish a canopy diametersimulation model. The stand position and corresponding spatial data on diameter at breast height wereused to generate a canopy distribution map. A Pearson Chi-square Test survey on the variations incanopy cover density between windward and leeward forest types revealed that while there was only a minor difference in the upper layer canopy cover density, it was not the case for the middle andlower layers. The result showed that the strong northeast monsoon, which destroys canopy structures,has a uniform effect on the upper layer canopy cover density. As the middle and lower stand layersare protected by the terrain and the upper stand layer, their canopy cover densities are notably different.