林木位置圖之製作與應用

Making and Application of Individual Tree Location Map

有鑑於過去林木位置圖製作既費時、又費工，效率低落，因此本研究旨在於如何更有效率的繪製林木位置圖。對其製作過程有詳細的描述，並且配合地理資訊系統建立永久樣區位置圖及樣區之林木位置圖。極力建議永久樣區之建立，應結合林木位置圖與單株之林木屬性資料，以成單木地理資料庫；結合樣區位置圖與林分屬性資料，為林分地理資料庫。本研究以惠蓀實驗林第三林班五個80m × 50m杉木試驗地及其樹幹解析木為例，建立單木地理資料庫，藉由空間統計可以處理分析林木的空間格局，導出樹冠投影圖與孔隙分佈圖，利用Hegyi競爭指數表林木間競爭的壓力、Schnute生長模式描述解析林木生長，更藉由參數探討單株林木間的距離與競爭對林木生長的影響，更而應用在疏伐決策上。結果顯示，林木的Hegyi競爭指數愈小時，其競爭壓力愈小，則生長潛能愈大，壽命愈長，最多可達400年生，直徑約可達65cm。所以進行疏伐，以減少各留存林木的競爭壓力，增加其生長潛能，有了林木地理資料庫，可以容易地進行疏伐、情境模擬。本研究依斷面積20%、40%、60%疏伐度的疏伐模擬、設計、規劃與疏伐木選擇、試驗。 The objectives of the paper are to make the individual tree location map efficiently and the procedures of making individual tree location map of permanent sampling plots (PSPs) with GIS are described. The attribute data of each tree were integrated with individual tree location map for tree geo-referenced database. To integrate the sampling plots location map with stand characteristics to be stand geo-referenced database. Geo-statistical procedures were used to analyze spatial patterns of the completely mapped tree data. Analyses were used to explore the effect of distance and competition to tree growth, too. The results of spatial analysis could be applied to do thinning design. In the study, there are five 80m × 50m sampling plots of Chain-fir in Hui-Sun Experimental Station were developed to be tree and stand geo-referenced database. Hegyi competition index and Schnute growth model were used to describe the individual tree competition and potential growth of tree. The smaller the Hegyi competition index, the less strees. The bigger the growth potential of the tree, the longer life span will exist. The maximum age of China-fir will be 400 years old. DBH be 65 em. So, need to do thinning for decreasing the competition strees and promoting the growth potential of the surveying tree. For there is geo-referenced database, we could do thinning design early. The scenarios of chinning design and selecting thinned tree will be easily to practice by the tree and stand geo-referenced database.

The objectives of the paper are to make the individual tree location map efficiently and the procedures of making individual tree location map of permanent sampling plots (PSPs) with GIS are described. The attribute data of each tree were integrated with individual tree location map for tree geo-referenced database. To integrate the sampling plots location map with stand characteristics to be stand geo-referenced database. Geo-statistical procedures were used to analyze spatial patterns of the completely mapped tree data. Analyses were used to explore the effect of distance and competition to tree growth, too. The results of spatial analysis could be applied to do thinning design. In the study, there are five 80m × 50m sampling plots of Chain-fir in Hui-Sun Experimental Station were developed to be tree and stand geo-referenced database. Hegyi competition index and Schnute growth model were used to describe the individual tree competition and potential growth of tree. The smaller the Hegyi competition index, the less strees. The bigger the growth potential of the tree, the longer life span will exist. The maximum age of China-fir will be 400 years old. DBH be 65 em. So, need to do thinning for decreasing the competition strees and promoting the growth potential of the surveying tree. For there is geo-referenced database, we could do thinning design early. The scenarios of chinning design and selecting thinned tree will be easily to practice by the tree and stand geo-referenced database.