本文旨在探討柳杉生長量及碳貯存量效益，本試驗研究區位於溪頭三叉崙為74年生之人工林，面積為0.0828ha。1945年第一次調查共栽植208株，林分密度為2600株/公頃，迄2010年僅餘33株柳杉試木，林分密度為413株/公頃，林分平均胸徑為40.4cm，平均樹高為21.1m，蓄積量為523.5m3/ha。林木成活率為15.86%，胸高斷面積由36.30m2增加至55.13m2，平均每年增加0.290m2，株數逐年減少但每公頃胸高斷面積則逐年增加趨勢。另本試驗結果顯示該區柳杉最適輪伐期依材積收穫最多為基準則為40年。
碳貯存部分以國內學者研究係數推算，其每公頃碳貯存量總計為31965.22 (公噸/ha) ，每公頃二氧化碳貯存量則總計為117205.79 (公噸/ha) ，每年平均約可貯存二氧化碳1583.86 (公噸/ha) 。以造林所需成本作為造林貯存二氧化碳之適應成本，貯存每公噸二氧化碳的成本為新台幣100.48元，換算美金為3.46元。此適應成本比直接在化石燃料利用方面去削減二氧化碳更為經濟，顯示造林貯存二氧化碳其成本較低。

This study aims to explore the growth of Cryptomeria japonica and its efficiency of carbon sequestration. This experimental plantation, located at Shantsalun area of Xi-Tou, is a 74-year-old forest plantation with an area of 0.0828 ha. Eighteen surveys were conducted between 1945 and 2010. The initial survey, conducted in 1945, showed a total of 208 individuals with a plantation density of 2600 trees /ha. However, The latest survey in 2010 showed only 33 individuals remained with a density of 413 trees / ha. The average DBH, tree height and stock volume were 40.4 cm, 21.1 meters, and 523.5m3 /ha, respectively. The survival rate for experimental plantation is 15.86%. Basal area of the forest was increased from 36.30 m2 in 1945 to 55.13 m2 in 2010, with an average annual growth rate of 0.290 m2. The number of trees per hectare was decreasing year by year, but the basal area was increasing. In addition, the result shows that the optimal rotation for Cryptomeria japonica is 40 years, which is consistent with previous studies.
　　By applying the transfer model of carbon sequestration developed by other studies, the estimated total carbon stock, total storage of carbon dioxide, and annual average storage of carbon dioxide were 31965.22 tons / ha, 117205.79 tons / ha, and 1583.86 tons / ha, respectively. The adaption cost for stock of carbon dioxide based on the cost of plantation is NT$100.48(or US$3.46) per ton of carbon dioxide, which is more economic compared with reducing the emission of carbon dioxide by using fossil fuel directly.