頁籤選單縮合
| 題 名 | Diatoms as Indicators of Environmental Changes: A Case Study in Great Ghost Lake=以矽藻為環境變遷指標之研究:大鬼湖為例 |
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| 作 者 | 吳俊宗; 莊佩佩; 吳麗容; 陳鎮東; | 書刊名 | Proceedings of the National Science Council : Part B, Life Science |
| 卷 期 | 21:3 1997.07[民86.07] |
| 頁 次 | 頁112-119 |
| 分類號 | 351.83 |
| 關鍵詞 | 矽藻; 環境變遷指標; 大鬼湖; Acidification; Diatom assemblage; Great ghost lake; Lake sediment; Palaeolimnology; pH indicator; Trophic state; |
| 語 文 | 英文(English) |
| 中文摘要 | 本文以湖積物中之矽藻為指標, 研究大鬼湖東北小湖之酸鹼性、營養態、腐水級 等在近千年來之變遷性形。大鬼湖海拔 2,150 公尺,其周圍為原始森林,從湖中所挖掘 50 公分長之湖積物中,其矽藻相以三種方法所推算之酸鹼度值均為弱鹼性,而與現在湖水之酸 鹼度值相近。現在湖水之營養態介於貧養和中養之間,此也與由湖積矽藻推算所得相近。酸 鹼度值在近千年來甚少變化,惟於近百餘年來有酸鹼度值略降底之現象,此時並同時有總碳 和總氮量的增高,以及腐水級及營養態略微下降的現象。從結果顯示,此種酸鹼度值降低之 現象,與國外所發現之百餘年來環境酸化之現象相似,推測此係與大氣污染物流入有關,而 非土地利用或林相改變所造成。本文應用由鴛鴦湖資料所導出之模式於此湖泊,發現可以適 用,結果並顯示,矽藻是研究湖泊環境變遷的良好指標。 |
| 英文摘要 | Diatom assemblages in the sediments of a tropical alpine Lake, Great Ghost Lake, were used in the present study as indicators of palaeo-environmental changes. At an altitude of 2,150 m, Great Ghost Lake is located in southern Taiwan within an undisturbed natural alpine forest. It is an oligotrophic and slightly alkaline lake. A sediment core, 50 cm long, was taken from the middle of the lake and used for the present study. Diatom assemblages in the sediments were used to infer the pH, total phosphorus, trophic state, and saprobity of the palaeo-environment. The diatom-inferred values matched well with the measured variables of present lakewater. The inferred pH values had retained a slight alkalinity over the last thousand years. A change in pH toward acidic values had occurred during the last century. The decrease in Ph was associated with a decrease in the saprobity and trophic state index values, and with enhancement of the amounts of total C and total N in the sediments. It is assumed that the decrease of pH was related to increased deposition of atmospheric pollutants rather than to land-use and vegetation changes. The results of the present study show that the regression model derived from Yuenyang Lake is applicable to this lake and suggest that diatoms are a good bioindicator for study of palaeo-environmental changes. |
本系統中英文摘要資訊取自各篇刊載內容。