六龜試驗林台灣杉人工林不同栽植密度胸高斷面積生長收穫模式比較

一個好的生長收穫模式應具備有生物生長解釋能力，預測能力及應用簡單性。本研究應用Nautiyal and Cauto (1982)與Chang(1984)以經濟生產函數層面所發展之生長收穫模式建立六龜地區不同栽植密度胸高斷面積之預測模式分別為：BA=exp[4.4470-12.8016/t-449768.8726/(pd^2)]（模式Ⅰ）及BA=exp[4.0753-69.7224/(t^2)-8535.1872/(t×pd)]（模式Ⅱ）。其R^2分別為0.74及0.72，相差不多，模式Ⅰ之數學結構是可經過原點的，隨時間變化，不同栽植密度有不同的胸高斷面積，不會隨著時間增加而收斂，其連年胸高斷面積生長量(CAI)的高峰點不受栽植密度影響，皆在同一林齡上，且胸高斷面積年生長率均相同，就整個林木生長生命週期而言並不適當；模式Ⅱ可說是模式Ⅰ的改良，在不同栽植密度下，最終會導致相同之胸高斷面積，連年胸高斷面積之生長高峰點隨栽植密度而不同，栽植密度高者高峰點較早，反之，高峰點則較晚，因此更接近林分生長的生物性質。以台灣杉人工林不同栽植密度31年生胸高斷面積爲檢測資料，二個模式經4種準則所得驗證結果皆顯示模式Ⅱ生長預測能力較好。

關鍵字

台灣杉；栽植密度；生長收穫模式

並列摘要

A good growth model should be capable of explaining biological growth, and predicting trends, as well a being simple to use. In this study, Nautiyal and Cauto (1982) and Chang's (1984) growth models based on economical production function were applied to establish predictive growth and yield models for Taiwania plantations of different planting densities in the Liukuei area: Model Ⅰ: BA=exp [4.4470-12.8016/t-449768.8726/(pd^2)] Model Ⅱ: BA=exp [4.0753-69.7224/(t^2)-8535.1872/(t×pd)]. R^2 for these 2 models at 0.74 and 0.72, respectively, are similar. However, the 1st model will pass through the origin, and the basal area of different planting densities will change, but will not converge with time. The peak of the current annual increment (CAI) occurs at the same age and all stand growth is at the same growth rate. It was not proper for describing the biological life cycle of trees. As for the 2nd model, it will converge to the same basal area over time for different planting densities, and allows the CAIs to reach their peaks at different ages. It is more reasonable in describing biological growth characteristics. Based on 4 criteria, the 31-yr-old planting density trial plantations validated that model Ⅱ would have better predictive power for the growth and yield of the basal areas of these plantations.

並列關鍵字

Taiwania ； planting densities ； growth and yield models

國際替代計量

六龜試驗林台灣杉人工林不同栽植密度胸高斷面積生長收穫模式比較

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