- 期刊
量化紅樹林地下部細根生物量
Quantifying fine root biomass in the soil of mangroves
摘要
沿岸濕地的碳存量為全球碳存量的12~15%，其中紅樹林土壤中的有機碳存量在全球碳循環中佔了重要的地位。紅樹林地下部生物量（尤其是直徑≤ 2 mm的細根）為主要貢獻者，在全球紅樹林碳存量均值為41%。過去研究多使用異速生長方程式（allometric growth equation）去推估紅樹林地下部生物量，可能會造成估算紅樹林地下部生物量的誤差，且因忽略細根的貢獻而造成地下部生物量之低估。本研究於2019年夏季及冬季分8層採取地表以下80 cm土壤樣本，測量臺南北門國家重要濕地中海茄苳（Avicennia marina）紅樹林細根生物量，同時探討紅樹林地下部根系生物量的環境影響因素。結果顯示，海茄苳地下部細根生物量兩季實測平均為5.018 kg DW m^(-2)，佔了異速生長方程式推估總地下部生物量（13.38 kg DW m^(-2)）的37.5%，表示異速生長方程式推估的數值低估了實際值；同時地下30 cm以下的有機質累積量（1.453 kg DW m^(-2)）亦遭到忽略，其佔總地下部有機質累積量的58.3%，這也表示有可能低估紅樹林下的沉積物有機碳存量。水質與土壤因子有明顯季節性變化，土溫變化及水淹沒時間導致細根生物量的季節性變化。
並列摘要
The carbon sink of coastal wetlands is 12-15% of the total carbon sequestration, and the organic carbon stock in mangrove soils plays an important role in the global carbon cycle. The mangrove belowground biomass (fine root diameter ≤ 2 mm) is the main contributor of the carbon stock, and the average mangrove carbon stock in the world may be up to 41%. In the past, the studies used the allometric growth equation to calculate the belowground biomass of mangroves, but it would result in error calculation of the belowground biomass. In this study, the soil of 80 cm depth was taken in summer and winter 2019. The fine root biomass of Avicennia marina in the Tainan Beimen was calculated to verify the allometric growth equation and to explore the relationship between root biomass and soil factors. The results show that the mean fine root biomass of Avicennia marina was 5.018 kg DW m^(-2), which accounted for 37.5% of the total belowground biomass (13.38 kg DW m^(-2)). This suggests that the estimate calculated by the formula is lower than the actual value. Similarly, 1.453 kg DW m^(-2) organic matter was neglected below the depth of 30 cm, indicating that the carbon stock in the soil was underestimated. Our results show that the seasonal change in temperature and moisture content in the soil might result in the seasonal change in fine root biomass.