深層土壤碳儲量的時間序列：以臺灣中部八卦台地南段河階地為例

Chronosequence of the Deep Soil Carbon Storage: An Example of Fluvial Terraces on the Southern of Pakua Tableland in Central Taiwan

徐進將(Chin-Chiang Hsu) ； 黃文樹(Wen-Shu Huang) ； 蔡衡(Heng Tsai) ； 黃旭村(Shiuh-Tsuen Huang)

《地理學報》 98期 (2021/04) Pp. 1-16

https://doi.org/10.6161/jgs.202104_(98).0001

摘要

自工業革命以來大氣二氧化碳濃度年年升高，在陸域生態系中擁有最大碳儲量的土壤，成為關注的焦點，了解不同生態系中的土壤碳儲量，將有助於擬定相關對策以減緩暖化效應的衝擊。儘管對土壤碳儲量的研究已累積許多成果，然多僅限於淺表層土壤，對於深層土壤有機碳的封存與時間的關係仍缺少訊息。臺灣中部八卦台地南段紅壤年代介於19-400 ka之間，已證實該階地土壤群形成一時間序列的關係，因此很適合用來探討土壤碳儲量在不同年代當中累積的狀態與速率。本研究結果顯示其碳儲量的累積速率與時間呈現指數函數的關係。然而淺層土壤因容易受到所在的環境因素所影響，碳儲量與時間的關係沒有固定模式。相較之下，深層土壤的碳儲量運用數學模式計算，分析出碳儲量會隨土壤深度增加而快速減少，而且在土壤深層（超過100 cm）碳儲量會減少至趨近穩定。然而這個土壤深層趨於穩定碳儲量的值，在八卦台地南段河階地與時間成反比關係，並且以每年0.024 kg/m^3的速率在減少中。

關鍵字

土壤有機碳 ； 碳儲量 ； 碳封存 ； 時間序列 ； 河階

並列摘要

The concentration of atmospheric CO_2 has increased and caused evident climatic warming during the past 100 years because of combustion of fossil fuels. The primary work to decrease the concentration of atmospheric CO_2, is to reveal the carbon flux and storage within varied ecosystems. The soil with the largest carbon stocks in the terrestrial ecosystem has become the focus of attention. Most studies have focused on the carbon stocks in the shallow soil, with few revealing the relationships between the sequestration of organic carbon and age in deep soils (depth in more than 1 meter). The lateritic soils of fluvial terraces dating 19-400 ka in the south of the Pakua tableland in central Taiwan are excellent for investigating the state and accumulation rate of soil carbon stock in different ages. Analytical results show that the accumulative rate of carbon stock is an exponential function with time. However, shallow soil carbon stock is susceptible to environmental factors, and the relationship between carbon stock and age has no fixed pattern. The mathematical model of the carbon stock of deep soil indicates that the carbon stock decreases rapidly with increasing soil depth and reaches a steady-state at depths below 100 cm. The deep soils on the terraces in the southern Pakua tableland tend to stabilize their carbon sequestration values in inverse proportion to age and decrease at a rate of 0.024 kg m^(-3)yr.

並列關鍵字

soil organic carbon ； carbon stocks ； carbon sequestration ； soil chronosequene ； fluvial terraces

參考文獻

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