棲蘭山天然更新台灣扁柏林分樹輪及材質之研究

Tree Ring and Wood Quality of Naturally Regenerated Chamaecyparis Obtusa var. Formosana Stand in Chi-Lan Mountain

林振榮(Cheng-Jung Lin) ； 林世宗(Shu-Tzong Lin) ； 鍾智昕(Chih-Hsin Chung)

《中華林學季刊》 43卷1期 (2010/03) Pp. 131-145

https://doi.org/10.30064/QJCF.201003.0009

摘要

本研究以棲蘭山台灣扁柏天然下種更新林木的生長特性、縱向壓縮強度及樹輪特徵值，探討林木生長對材質的影響，其結果顯示胸徑、樹高、樹冠長、樹冠幅、樹冠比之間具有顯著性的正相關，樹冠幅度指數與胸徑、樹高、樹冠長、樹冠幅、樹冠比之間具有顯著性的負相關。本研究地區台灣扁柏樹輪密度與早材密度、最小密度、晚材率三個參數之間有顯著性正相關存在。以縱向壓縮強度及樹輪寬度在樹幹橫向的變異性及分段迴歸法分析，界定棲蘭山台灣扁柏天然更新林木成熟材及未成熟材的境界，約在25~30年生形成。樹輪密度及壓縮強度與林木大小有顯著性的負相關性存在，但是相關係數偏低，表示棲蘭山台灣扁柏天然更新林木在幼期生長階段對材質變化影響小，以上提供經營台灣扁柏天然更新林分的參考。

關鍵字

台灣扁柏 ； 天然更新 ； 生長特性 ； 樹輪特徵值

並列摘要

The purpose of this research was to explore the tree ring and wood quality of naturally regenerated Chamaecyparis obtusa var. formosana in Chi-Lan Mountain based on the relationship between tree growth, compressive strength and ring characteristics. The results revealed that there were very significant positive relationships among diameter at breast height (DBH), tree height (TH), crown length (CL), crown width (CW), and live-crown ration (LCR). However, there were very significant negative relationships between crown shape ratio and DBH, TH, CL, CW, LCR. The ring density was related to earlywood density, minimum density in a ring, and latewood percentage. There were significant negative relationships between wood properties (ring density and compressive strength) and DBH and TH, even though the coefficients of relationships were small. The position of demarcation between juvenile and mature wood occurred at about 25-30 years of cambium age by ring width and compressive strength variation and segmented regression analysis. The tree ring density and compressive strength were not correlated to tree DBH growth rate and tree height of Taiwan yellow cypress in Chi-Lan Mountain. These results suggested that natural regenerated Taiwan yellow cypress stand at juvenile stage in Chi-Lan Mountain area will likely not to have a large impact on wood properties.

並列關鍵字

Chamaecypress obtusa var. formosana ； Natural regeneration ； Growth characteristics ； Ring characteristics