溪頭台灣杉人工林之林分特性與發展

Stand Properties and Development of ＂Taiwania Cryptomerioides＂ Plantations in Xitou, Central Taiwan

鄭智馨(Chih-Hsin Cheng) ； 洪志祐(Chih-Yu Hung) ； 黃于軒(Yu-Hsuan Huang) ； 李俊佑(Chung-Yu Lee) ； 陳秋萍(Chiou-Pin Chen) ； 白創文(Chuang-Wen Pai)

《中華林學季刊》 47卷2期 (2014/06) Pp. 155-168

摘要

台灣杉（Taiwania cryptomerioides）俗稱亞杉，是台灣特產之造林樹種，也是溪頭重要造林樹種之一。溪頭台灣杉人工林的林木生長與林分發展研究，主要依據台灣杉生長量試驗地與溪頭林木植栽密度試驗地等試驗地結果，較為缺乏不同造林樣地的整合資料。本研究藉由調查溪頭四塊林齡介於22-74年的台灣杉人工林，評估溪頭台灣杉人工林的林分密度、林木平均胸高直徑、林分高度、林分胸高斷面積、林分材積與林分林木碳量等林分特性及這些林分特性隨林齡之發展。研究結果顯示調查林分的林木平均胸高直徑、林分高度、林分胸高斷面積、林分材積與林分林木碳量，分別介於22.6-54.1 cm、18.7-32.8 m、47.1-94.4 m^2 ha^(-1)、320-918 m^3 ha^(-1)與93-268 Mg C ha^(-1)間，這些林分特性不僅隨林齡增加而增加，且於造林70年內仍未明顯趨緩。研究結果也顯示，相同林齡的溪頭台灣杉人工林較柳杉人工林有較佳的林木生長；同樣地，相同林齡的溪頭台灣杉人工林也較六龜地區台灣杉人工林呈現較高的林分材積與林分林木碳量，其主要原因在於溪頭台灣杉林木的較高樹高，而非林木胸高直徑與林分胸高斷面積的差異。對現有台灣杉人工林而言，可將規劃成為長輪伐期之樹種，培育大徑木用材之生產，而極佳碳儲存量的台灣杉人工林地，也可幫助將大氣二氧化碳固定於林木中，減緩氣候變遷與全球暖化。

關鍵字

台灣杉 ； 林齡 ； 胸高直徑 ； 胸高斷面積 ； 林分林木碳量

並列摘要

＂Taiwania cryptomerioides＂ is a native tree species in Taiwan and represents an important species for plantations in many areas of Taiwan, including Xitou, central Taiwan. The understanding of stand properties and development of ＂Taiwania＂ plantations in Xitou, however, is only based on the studies from two permanent experimental plots and lacks spatial variation to have the integrated information. In this study, we investigated four ＂Taiwania＂ plantations with stand age between 22 and 74 years to evaluate their stand properties, including stand density, mean diameter at breast height, stand height, basal area, stand volume, and tree biomass carbon stocks, and the stand development of these properties with age. The results showed mean diameter at breast height, stand height, basal area, stand volume, and tree biomass carbon stocks of the selected four ＂Taiwania＂ plantations ranged at 22.6-54.1 cm, 8.7-32.8 m, 47.1-94.4 m^2 ha^(-1), 320-918 m3 ha^(-1), and 93-268 Mg C ha^(-1), respectively. The values of these stand properties increased with stand age and did not level off within 70 years of age. The results also indicated the stand developments in ＂Taiwania＂ plantations in Xitou were faster than these in Japanese cedar plantations. In addition, the stand developments of ＂Taiwania＂ plantations in Xitou were faster than those in Luikuei, southern Taiwan, mainly due to their taller tree height in Xitou not the differences in diameter at breast height and basal area. Therefore, the ＂Taiwania＂ plantations have the potential to produce large round log by extending the rotation period. With their great tree biomass carbon stock, the ＂Taiwania＂ plantations can also be applied to sequestrate atmospheric carbon dioxide and mitigate the climate change and global warming.

並列關鍵字

＂Taiwania cryptomerioides＂ ； Stand age ； Diameter at breast height ； Basal area ； Tree biomass carbon stock