Detection of Electric Resistivity Tomography and Evaluation of the Sapwood-Heartwood Demarcation in Taiwan Red Cypress (Chamaecyparis formosensis) Trees

電阻係數斷面影像法應用於台灣紅檜立木檢測及邊心材境界之評估

林振榮(Cheng-Jung Lin) ； 鍾智昕(Chih-Hsin Chung)

《林產工業》 31卷2期 (2012/06) Pp. 61-69

https://doi.org/10.6561/FPI.2012.31(2).4

摘要

樹木邊材及心材的性質在各種木材利用方面具有重要的意義，本研究檢測紅檜樹木（Chamaecyparis formosensis）的電阻係數斷面影像（ERT）及相符合的電阻係數（ER）分佈圖。使用生長錐取樣立木的樹芯，測定邊心材境界的位置，並由ERT中獲得邊心材境界位置相符的ER值。由ERT中獲得的邊心材境界ER值與ERT中最高ER及最低ER合計值（ERmax + ERmin），兩者之間具有顯著性的正相關（R2=0.83, p ＜ 0.01），透過統計方法，邊心材境界ER值可以由ERT中的ERmax+ERmin合計值推算出，因此，可由ER值評估邊心材境界之位置。本研究結果得知ERT技術可以使用作為非破壞技術檢測紅檜立木邊心材境界的位置，瞭解樹幹橫斷面的電阻係數特性，作為一種評估樹木健全性的方法。

關鍵字

電阻係數 ； 斷面影像 ； 非破壞性技術 ； 紅檜

並列摘要

The proportions of sapwood and heartwood of trees have significant impacts on the utilization of wood. Electric resistivity tomography (ERT) and corresponding electric resistance (ER) value maps were examined in Taiwan red cypress (Chamaecyparis formosensis) trees. The position of the sapwood-heartwood demarcation was measured on incremental cores from living trees and the corresponding ER of the sapwood-heartwood boundary was acquired from the ER map. A positive significant relationship was found between the maximum ER plus minimum ER values (ERmax + ERmin) and ER of the sapwood-heartwood demarcation from the tomographic data. Additionally, the position of the sapwood-heartwood demarcation was determined by corresponding ER, and the critical ER can be established by the value of (ERmax + ERmin) of the tomographic data. The experimental results from this study indicated that ERT technique can be used to determine the position of the sapwood-heartwood boundary and can serve as a technique to determine the healthy condition in the living trees of Taiwan red cypress.

並列關鍵字

Electric resistivity ； Tomography ； Nondestructive technique ； Taiwan red cypress (Chamaecyparis formosensis).