The Importance of Litter Biomass in Estimating Soil Organic Carbon Pools in Natural Forests of Taiwan

枝葉層在台灣天然林土壤碳庫估算之重要性

張朝婷(Chao-Ting Chang) ； 王巧萍(Chiao-Ping Wang) ； 邱祁榮(Chi-Zong Chou) ； 杜清澤(Chin-Tzer Duh)

《台灣林業科學》 25卷2期 (2010/06) Pp. 171-180

https://doi.org/10.7075/TJFS.201006.0171

摘要

枝葉層為森林生態系中重要的碳庫，其有機碳也最易受到氣候變遷與人為經營的影響，然而一直以來森林枝葉層生物量在土壤碳庫調查工作上卻常常被忽略。本研究調查分析台灣海拔390~3000 m的四個主要氣候區（熱帶、亞熱帶、溫帶與冷溫帶）中八個天然林之枝葉層生物量、土壤容積密度、細土含量及其碳濃度，以瞭解枝葉層在台灣天然林土壤表層碳庫估算上之重要性。分析結果得知，高海拔溫帶天然林每公頃之碳庫存量為低海拔之熱帶與亞熱帶天然林之2~3倍。台灣天然林枝葉層碳貯存量所佔土壤碳庫比例，以熱帶林最低(4.0%)、而溫帶林最高(38.8%)，可知在台灣中高海拔地區的天然林，枝葉層在表層20 cm土壤碳儲存量中扮演極重要的角色；且在估算溫帶至冷溫帶森林碳吸存與釋放潛能時，更應重視此易於礦化之枝葉層。表層土壤與枝葉層之碳庫存量與溫量指數呈明顯正相關(R=0.95)，而與雨量無關，顯示台灣天然林枝葉層之累積速率與表土碳庫主要受控於溫度。

關鍵字

森林土壤有機質 ； 枝葉層 ； 碳庫存 ； 氣候區 ； 溫量指數

並列摘要

Litter layers store a significant reservoir of carbon in forest ecosystems and are prone to be impacted by climate change and anthropogenic management practices. However, estimating forest litter biomass is commonly neglected in soil surveys. In this study, litter biomass, soil bulk density, fine soil content, and C concentration of the top 20 cm of topsoils were analyzed for 8 natural forests at elevations ranging 390~3000 m located within 4 climate zones (tropical, subtropical, temperate, and cool-temperate climate) to understand the importance of forest litter biomass in estimating soil organic carbon (SOC) pools in Taiwan. Natural temperate forests at high elevations stored 2~3 times the C per hectare than did warm tropical and subtropical ones. The proportion of the litter C pool in topsoils increased with elevation and was highest in the temperate forest (28.8%) and lowest in the tropical forest (4.0%). These results suggest that when estimating the potential of forest C sequestraion and release, temperate and cool-temperate forest litter layers should be of great concern since these C pools are considerably less well protected. The warmth index (WI) was significant positively correlated with litter C pools and SOC stocks (R=0.95), while there was no correlation between the annual precipitation and litter and SOC pools, indicating that litter accumulation and the SOC content in Taiwan are mainly controlled by temperature rather than precipitation.

並列關鍵字

forest soil organic carbon ； litter layer ； C pool ； climate zone ； warmth index