台大實驗林森林生態系不同林分經營策略之碳貯存效果

Carbon Sequestration Effects in Different Forest Ecosystem Management Scenarios in Experimental Forest, National Taiwan University

李國忠(Kou-Chung J. Lee) ； 林俊成(Jiunn-Cheng Lin) ； 賴建興(Chain-Shen Lain) ； 林麗貞(Li-Chen Lin)

《國立臺灣大學生物資源暨農學院實驗林研究報告》 18卷4期 (2004/12) Pp. 261-272

https://doi.org/10.6542/EFNTU.200412_18(4).0002

摘要

本研究針對台大實驗林生態系經營示範區內之人造森林，以野外調查資料推估各樹種之生長潛力，再以碳吸存評估模式模擬不同林分經營策略（維持現況、伐採後不造林、伐採後再造林、考慮林木利用率）之碳吸存潛力。結果顯示：區內柳杉、台灣杉、杉木、紅檜純林及其混淆林，面積984.77公頃，碳吸存總量共43,589公噸，平均每公頃碳吸存量為44.26公噸。推估現有柳杉人造森林不同林分經營策略在20年後的變化：如維持現況，碳吸存量為46,427公噸。當每年伐採5公頃，且伐採後並不再造林，碳吸存量為29,535公噸。如伐採後再造林，再造林樹種為台灣櫸時，碳吸存量為33,935公噸。如加上考慮木材利用率時，會因再造林樹種的不同及原先伐採單位面積的大小而使固定於林產品的碳量有所差異。當每年伐採5公頃，且伐採後並不再造林，在木材利用率為65%時，碳吸存量為48,734公噸。如伐採後再造林，再造林樹種為台灣櫸時，在木材利用率為65%時，碳吸存量為53,134公噸。可見適當的林分經營對人造森林碳吸存量有正而助益。

關鍵字

柳杉 ； 態系經營 ； 碳吸存

並列摘要

This study estimated the growth potentials for five man-made tree species in Example Area of Forest Ecosystem Management, NTU Experimental Forests and assessed the carbon sequestration capacities via simulation models under four different management scenarios keeping present condition, non-reforestation after cutting, reforestation after cutting, and considering timber usage rate. The average carbon sequestration quantity in the study area (984.77 ha) is 44.26 ton/ha. It shows that in the Japanese Cedar man-made stands, the total carbon sequestration quantities under different management scenarios will be 46,427 ton if the management strategies remain the same in the following 20 years, 29,535 ton if 5 hectares are cut annually without reforestation, and 33,935 ton if Zelkova serrata is replanted after annual cutting. When considering timber usage rate, the carbon sequestration quantities vary with different replanting species and culling areas. It reveals that with 65% of timber usage rate the carbon sequestration quantities will be 48,734 ton if 5 hectares are cut each year without reforestation, and 53,134 ton if Zelkova serrata is replanted after cutting. The results suggest that suitable stand management strategies improve the carbon sequestration in man-made forests.

並列關鍵字

Japanese cedar (Cryptomeria japonica) ； ecosystem management ； carbon sequestration