Stand Development and Aboveground Biomass Carbon Accumulation with Cropland Afforestation in Taiwan

台灣農地造林之林分發展與地上部林木碳量蓄積

鄭智馨(Chih-Hsin Cheng) ； 黃于軒(Yu-Hsuan Huang) ； Oleg V. Menyailo ； 陳建德(Chien-Teh Chen)

《台灣林業科學》 31卷2期 (2016/06) Pp. 105-118

https://doi.org/10.7075/TJFS.201606_31(2).0003

摘要

低碳濃度地區的造林提供了減緩氣候變遷的有效方法，因為造林林木可固定引起氣候變遷的大氣二氧化碳。但除固碳效益外，造林仍具有其它生態或生產效益，使得不同樹種與不同地點間的造林計畫可能增加固碳效益推估上的難度。本研究總共調查台灣22個農地造林樣區，包含12種樹種與4個研究地點，研究目的主要為調查現有台灣農地造林的林分發展與地上部林木碳量蓄積，並分析不同數種與不同地點的差異如何影響林木生長。調查結果顯示經過8~10年的造林，所有調查樣區的平均胸高直徑、樹高、林分密度與地上部林務碳量分別為12.1 cm、8.5 m、1272 trees ha-1與32.1 Mg C ha-1，並以速生的大葉桃花心木(Swietenia macrophylla)與苦楝(Melia azedarach)有最高的生長速率與林木碳量蓄積，櫸樹(Zelkova serrata)則呈現最低的生長速率與林木碳量蓄積。生長於土層深厚的造林林木，也較生長於土層薄淺且含石量高的造林林木有較佳的林木生長。整體而言，農地造林可增加林地碳吸存，也具有增加林木經濟與生態效益。

關鍵字

造林 ； 農地 ； 碳吸存 ； 林分特性 ； 土壤厚度

並列摘要

Afforestation in low-carbon-density areas has been proposed for mitigating climate change, because it leads to a reduction in the atmospheric carbon dioxide concentration. However, afforestation can be conducted for numerous purposes, and the complexity of tree species may render accurate estimation of the carbon (C) sequestration potential difficult. In this study, 22 cropland afforested plantations among 12 tree species and 4 study sites were investigated. We investigated stand development and aboveground biomass C accumulation of cropland afforestation in Taiwan, and examined how tree species and site conditions affected stand growth and yields. Results showed that average values of the mean diameter at breast height, tree height, stand density, and aboveground biomass C stocks for all studied plantation at 8~10 yr after planting were 12.1 cm, 8.5 m, 1272 trees ha^(-1), and 32.1 Mg C ha^(-1), respectively. The results also revealed that fast-growing tree species such as Swietenia macrophylla and Melia azedarach attained the highest growth rates and accumulated the most biomass C stocks, whereas slow-growing tree species such as Zelkova serrata exhibited the lowest growth rate and C accumulation potential. Trees grown at sites with deep soils outperformed those grown at sites with shallow and rocky soils. Overall, current cropland afforestation in Taiwan can enhance C sequestration, and also generate economic and ecological benefits.

並列關鍵字

afforestation ； cropland ； carbon sequestration ； stand characteristics ； soil depth