林務局普通施業地人工林生長與收穫之分析

An Analysis of the Growth and Yield of Man-made Forest in Taiwan

張森(Joseph S. Chang) ； 陳麗琴(Lih-Chin Chen) ； 任憶安(I-An Jen)

《林業試驗所研究報告季刊》 2卷1期 (1987/03) Pp. 17-29

https://doi.org/10.7075/BTFRI.198703.0017

摘要

由於本省林產工業近年來對木材之需求極大，而自給率僅爲10%，爲求自給率的提高，經營人工林以提高生産量，多年一直是林務局努力的方向。本研究僅對林務局所轄各林管處普通就行了業地內人工林生長與收穫狀況作一分析，了解不同齡級及林型下之面積與蓄積分段狀況，並應用指數函數方程式檢定其最適之生長與收穫模式，結果顯示各林管處普通施業地內造林地生産力有極明顯之差異，文山，恒春二處林木生長甚差，竹東，大甲等處生長良好。今後五年人工林生長量爲三百萬立方公尺，平均年生長量60萬立方公尺，現有全部人工林地年平均生長量不足5立方公尺/公頃，與天然闊葉樹林生長並無不同，經營人工林以提高生產力的目標顯然落空。因此嚴格要求降低造林成本，並全面探討臺灣伐木造林，林相變更等作業，實屬必要。

並列摘要

In recently years, due to great timber demand of Taiwan's forest product industry and only 10% self-supply rate of timber, Taiwan Forestry Bureau has made great effort to increase self-supply rate and promote productivity by converting natural forests into plantations.
The purpose of this study was to analyze the growth and yield of the plantations of forest districts in Taiwan. The forest area and growing stocks distribution under different timber age classes and forest types were calculated. The optimal growth and yield models were established by means of exponential function equation. The results were as follows: The timber productivity were significantly difference among 13 forest districts (see appendex 1, 2). Generally speaking, the timber growth of Wen-shan and Heng-chun forest districts was very low, while that of Chu-tung and Ta-chia forest districts was quite high. It was estimated that increment, growth for the next 5 years was 3,000,000m^3. MAI of all plantations was not over 5M^3/ha, which was not different from that of natural hard wood stands. Under this circumstance, precise control of planting costs and revising timber harvest policy is necessary.