煤礦棄土地大頭茶抗鋁毒害機制之研究

Aluminum Toxicity Resistant Mechanism of Taiwan Gordonia in Coal Mine Spoil

鐘旭和(Hsu-Ho Chung) ； 顏江河(Chiang-Her Yen)

《台灣林業科學》 12卷2期 (1997/06) Pp. 167-175

https://doi.org/10.7075/TJFS.199706.0167

摘要

本省北部煤礦棄土地，土壤pH值極低，土壤與土壤水中的鋁離子含量極高，但仍有大頭茶自然分布其間，顯然大頭茶具有特殊的生理機制，能克服如此瘠劣的生育地環境。本研究即以該樹種為材料，探討大頭茶的耐／抗鋁機制。首先分析裸露棄土與大頭茶植土地的土壤與土壤水中的鋁離子含量，其結果證實大頭茶極顯著地降低土壤與土壤水中的鋁離子含量，並確定土壤水中鋁物種型態Al(上標 +3)佔89.86%，Al-SO4佔8.14%，AlF2(上標 +)佔1.20%，ALF(上標 2+)佔0.80%；分析生長於礦區及非礦區大頭茶植物體內鋁及各種養分的分配情況，證實鋁進入值物體內會在葉部與細根處堆積，且濃度高達1900 mg/kg，而與生長於非礦區者呈極顯著差異。分析大頭茶木質部汁液證實鋁在大頭茶體內的輸送形態主要以AlF2(上標 +)(95.34%)與AlF(上標 2+)(3.45%)為主，僅有1.21%偽A1(上標 3+)形態。大頭茶生長於高鋁含量土壤中，經由吸收氟離子螯合鋁離子以降低鋁毒危害，因而降低土壤與土壤水中的鋁含量，至於堆積在葉部與細根的高濃度鋁其型態為何？如何避免鋁毒危害？仍須進一步探究。

關鍵字

煤礦棄土地 ； 鋁毒害 ； 大頭茶

並列摘要

Coal mine spoil is notorious for its high aluminum (Al) content and low pH. Naturally distributed Taiwan gordonia (Gordonia axillaris Dietr.), however, grows well on spoil located in northern Taiwan. The present study, therefore, was designed to investigate the aluminum resistant/tolerant mechanism in this species. We first analyzed the contents of Al ions both in bare spoil and in spoil where Taiwan gordonia trees are found. Results show that the presence of this species significantly decreases the contents of Al ions in soil and soil solulion of coal mine spoil. Analyses of the Al ions in soil solution show that 89.86% are Al(superscript 3+), while Al-SO4, AlF2(superscript +), and AlF(superscript 2+) account for 8.14%, 1.20%, and 0.80%, respectively. Results of tissue nutrient analyses show that, for those Taiwan gordonia grown on coal mine spoil, Al, once absorbed, is accumulated in leaf tissues and in fine roots. Al content in these tissues was found to be as high as 1900 mg/kg which is significantly (p＜0.05) higher than that found in the same tissues of Taiwan gordonia from normal sites adjacent to the coal mine spoil. Analyses of Xylem sap show that Al transport forms in Taiwan gordonia are mainly as AlF(superscript 2+) (95.34%) and AlF2(superscript +) (3.45%); and only 1.2% is in the form of Al(superscript 3+). These results suggest that Taiwan gordonia alleviates A1 toxicity by cheating the A1(superscript 3+) with absorbed fluoride ions. As such Taiwan gordonia grown in high-Al soil (such as coal mine spoil) is capable of uptaking and, hence, reducing soil Al contents. To fully elucidate the Al toxicity resistant/tolerant mechanism, more studies on the forms of accumulation in leaf tissues and fine roots are still needed.

並列關鍵字

coal mine spoil ； Al toxicity ； Gordonia axillaris