臺灣固有樹種臺灣移（Taiwania cryptomerioides Hay.)，自1970年代起即為臺大實驗林重 要造林樹種之一。天然生林木分布於本省中部1,800〜2,600 m山區，樹高可達60 m，胸徑可達2〜3 m。本研究首先調查人工林臺灣杉的樹輪半徑生長特性，以作為後續提供氣候如何影響臺灣杉生 長的研究參考。於2013年間於臺灣中部之臺大實驗林溪頭、清水溝、水里及内茅埔營林區内臺灣 杉人工林進行取樣，樣區林齡自38至76年生，共鑽取166株樣木，依樹輪學標準方法進行乾燥砂磨 等處理後，挑選相關性良好者建立樹輪年表。研究結果顯示人工林臺灣杉樹輪生長具有下列三種 特性：（1)於早晚材之際出現明顯之偽輪；（2)於生長季初期出現重年輪；（3)不論幼齡林或較老齡林 (>60年生)的臺灣杉，均無明顯生長休眠期的現象。調查數據顯示臺大實驗林的人工林臺灣杉，半 徑生長速率之平均值為4.7〜6.6 mm yr-1。

Taiwan fir (Taiwania cryptomerioides Hay.), a native of Taiwan, is one of major plantation species of NTU Experimental Forest since 1970s. Usually scattered throughout the Central Mountain Range at altitudes of 1,800-2,600 m, trees of the species can be up to 60 m high and 2-3 m in diameter. In order to understand how climate influences the growth of the species, this study aims to investigate the radial growth characteristics of plantation Taiwan firs in NTU Experimental Forest via tree ring analysis. Six plantations, with ages ranging from 38 to 76 years, were investigated. A total of 166 trees were cored using increment bores. Following the standard dendrochronological procedures, cores were dried,mounted, and sanded to proper surface smoothness. The results showed: (1) false rings occurred frequently during earlywood-latewood transitions; (2) double rings also frequently occurred at the beginning of growing season; (3) Taiwania lacked a clear dormancy and might not stop growing in some years. Besides earlywood and latewood boundaries often were not clear, and it happened to both young and older (> 60 year-old) trees. Taiwania radius growth rates are 4.7 〜6.6 mm yr-1.