復育造林初期土壤呼吸的季節變化與土壤碳儲量

Seasonal Variation of Soil Respiration and Soil Carbon Storage Following Reforestation

江博能(Po-Neng Chiang) ； 賴彥任(Yen-Jen Lai)

《國立臺灣大學生物資源暨農學院實驗林研究報告》 33卷3期 (2019/09) Pp. 183-196

https://doi.org/10.6542/EFNTU.201909_33(3).0004

摘要

本研究目的為釐清復育造林初期土壤呼吸的季節反應以及土壤碳儲量。本研究中孟宗竹林、臺灣杉人工林及復育造林三個不同林區年土壤呼吸量分別為9.51、8.70及10.85 Mg C ha^(-1) year^(-1)。不同造林地間，土壤呼吸速率最低值與最高值分別出現在1－2月（冬季）及7－8月（夏季）。土壤溫度與土壤水份在時間變化下與土壤呼吸速率呈指數顯著相關，表示土壤溫度與土壤水份為主要控制土壤呼吸速率主要因子。在三種不同造林地中，土壤水分含量於本研究中介於19%－25.2%間可達最大土壤呼吸速率。復育造林土壤碳分布受到林木種類不同以及土地利用型所影響。本研究結果顯示復育造林初期地上物被移除後，降雨導致地表逕流增強，土壤腐質層移出以及土壤表面因日照增加，造成土壤表面溫度上升，增加土壤呼吸作用下，致使土壤碳儲量降低。

關鍵字

碳儲存 ； 復育造林 ； 季節變化 ； 土壤呼吸 ； 空間變化

並列摘要

This study aims to clarify the seasonal variation of soil respiration (SR) and soil carbon storage following reforestation. We studied the mechanism of soil respiration processes and environment impact. The results showed that the average SR amount of moso-bamboo, Taiwania, and reforestation plantation were 9.51, 8.70, and 10.85 Mg C ha^(-1) year^(-1), respectively. The lowest and highest soil respiration rates were revealed in January-February (winter) and July- August (summer). Soil temperature (ST) and soil moisture (SM) were found to significantly relate with SR rate in temporal variation, indicating that both ST and SM were the major controlling factors to SR rate. In addition, maximum soil respiration rate was found in soil moisture ranging between 19%-25.2% in the three different plantations. Furthermore, we also found that soil carbon distribution was affected by tree species and land use. As a result, we concluded that after the removal of the aboveground biomass following reforestation, the increased surface runoff due to rainfall, the removed soil litter, and the greater soil surface due to irradiation could cause ST and SR to increase, resulting in decreased soil carbon storage.

並列關鍵字

Carbon storage ； reforestation ； seasonal variation ； soil respiration ； spatial variation