應用生長模式模擬溪頭地區不同齡級紅檜人工林單木之直徑生長

USING GROWTH MODELS TO PREDICT DIAMETER GROWTH FOR DIFFERENT AGE CLASSES OF TAIWAN RED CYPRESS (CHAMAECYPARIS FORMOSENSIS) IN XITOU

賴韻如(Yun-Ju Lai) ； 王亞男(Ya-Nan Wang) ； 顏添明(Tian-Ming Yen)

《中華林學季刊》 50卷2期 (2017/06) Pp. 145-158

摘要

本研究之目的在於探討不同生長模式應用於紅檜(Chamaecyparis formosensis)人工林不同齡級單木生長之適用性。研究區域位於臺灣中部之紅檜人工林長期試驗樣區(120°47'44＂E, 23°39'55＂N)，調查不同時期樣木之生長資料，總共數量為114株，並將其區分為3個齡級，齡級I-III分別為46、23、45株。本研究採用6種生長模式模擬單木胸高直徑生長，模擬後以殘差均方根(The root mean squared error, RMSE)評估各模式之模擬效果，研究結果顯示Chapman-Richards及Modify-Weibull模式無法成功模擬全部樣木，但其餘4種模式則可成功模擬。本研究進一步以重複量數變異數分析檢測不同齡級內各模式之RMSE值的差異性，所得結果呈現齡級I和III具有顯著性差異，表示此2齡級內之生長模式模擬效果有所不同，以齡級III為例，3參數的生長模式之模擬效果明顯的優於2參數的生長模式。此外，本研究於各齡級選取1株代表性的樣木為例，探討觀測值和模式模擬結果的配適情形，以瞭解生長模式在不同齡級的適用性。

關鍵字

生長模式 ； 人工林 ； 紅檜

並列摘要

The purpose of this study was to examine the predictability of different growth models for different age classes of Taiwan red cypress (Chamaecyparis formosensis) at tree level. The study site belongs to a long term trial of Taiwan red cypress plantations in central Taiwan (120°47'44＂E, 23°39'55＂N). The sample trees were surveyed at various periods and a total of 114 samples were obtained. All samples were classified into 3 age classes where classes I to III contained 46, 23 and 45 trees, respectively. We employed 6 growth models to predict diameter at breast height (DBH) growth of trees and then examined these by the root mean squared error (RMSE). However, the Chapman-Richards and Modify-Weibull models could not successfully fit all samples, whereas the others could fit all. We further used the repeated measures analysis of variance (RM-ANOVA) to examine the RMSE among growth models for different age classes and only the age classes I and III had significant differences. It indicated that the RMSE had differences among growth models in these two age classes. For instance, the 3-parameter models were obviously superior to the 2-parameter model. In addition, one tree each was sampled for each age class as an illustration to show the fitness between the observations and growth models. It helps evaluate the predictability of the growth models for age classes.

並列關鍵字

Growth model ； Plantations ； Taiwan red cypress (Chamaecyparis formosensis)