第四紀(jì)異常氣候環(huán)境與地質(zhì)微生物2013年度報告

胡超涌　黃俊華　賴旭龍　周煉

摘 要：第四紀(jì)異常氣候下微生物的響應(yīng)和反饋的研究不但對了解現(xiàn)代全球變暖背景下微生物與氣候變化之間的關(guān)系具有啟示作用，同時對也為地質(zhì)歷史時期微生物和環(huán)境之間的協(xié)同演化的假設(shè)提供驗證的案例。因而，第四紀(jì)異常環(huán)境下地質(zhì)微生物的研究是聯(lián)系微生物作用的現(xiàn)代過程與地質(zhì)過程的橋梁。該研究借助于洞穴沉積物、泥炭沉積物和長江中游的湖泊沉積等地質(zhì)載體，建立評估不同環(huán)境典型微生物地質(zhì)過程的分子和原子（同位素）水平的示蹤技術(shù)方法，查明微生物通過影響碳循環(huán)等地質(zhì)地球化學(xué)過程對地質(zhì)環(huán)境的作用。在前期的研究基礎(chǔ)上，2013年的研究取得以下重要進(jìn)展：（1）利用石筍碳酸鹽熱釋光對土壤生物過程進(jìn)行了示蹤，獲得土壤有機質(zhì)分解與微生物降解過程的信息，發(fā)現(xiàn)了溫度對土壤呼吸的影響，為未來全球變暖下土壤碳庫大小的評估提供依據(jù)；（2）對發(fā)生在全新世的一次氣候異常事件進(jìn)行了解剖，發(fā)現(xiàn)東亞季風(fēng)區(qū)8.2 ka BP氣候事件的石筍記錄與著名的格陵蘭冰芯氧同位素記錄具有高度相似性，說明在北大西洋降溫和東亞季風(fēng)減弱之間存在密切氣候耦合；（3）開發(fā)了GDGTs和霍類化合物兩個表征古水文的指標(biāo)，并成功地用于古環(huán)境的重建，有望為預(yù)測全球變暖過程中不斷出現(xiàn)嚴(yán)重的洪災(zāi)和旱災(zāi)的預(yù)測和防范發(fā)揮作用；（4）建立了微生物脂類定量重建古溫度的新方法，探索地球表層長期溫度的波動，為評估自然條件下地球環(huán)境變化的頻率和強度提供基礎(chǔ)資料；（5）第四紀(jì)動物演化及其對環(huán)境變化的響應(yīng)的研究，對當(dāng)今全球變暖的適應(yīng)性具有啟示作用。

關(guān)鍵詞：第四紀(jì) 氣候 地質(zhì)微生物 石筍 泥炭

Abstract： To understand the microbial response and feedback under Quaternary climatic anomalies is a important scientific issue， which provide not only a analogy to the relationship between microorganisms and climate change in the ongoing global warming， but also a validation case to test the interaction hypothesis between the microbes and the earth environment in geological scale. Thus， the study of Quaternary geobiology in an abnormal environment builds a link of modern processes to deep times. In this project， some geological materials， such as speleothem， peat and lake sediments were analyzed to extract the detailed messages of geobiology and environment by the advanced techniquese with a detect level of atoms or molecules. Based on this data， we investigate the interaction between the Quaternary microbes and the climate. We found， （1）the response of thermoluminecence in speleothem to the content of humic acid originated from the biological decomposition of organic matter， a temperature dependent process in soil； （2）the duration and evolution of the climate event about 8，200 years ago from a sub-annually resolved stalagmite record from central China， is indistinguishable from that observed in the Greenland ice cores， implying an effective and rapid atmospheric teleconnection existed between the North Atlantic and the monsoon system during the early Holocene； （3）the dependence of the GDGTs and hopanoid in peat on the water level in wetland， provided a novel proxy for reconstruction of paleaohydrology； （4）the microbial lipids based temperature fluctuation during the geological time， implying a nature forcing for climatic variation； （5）an evolution spectrum of quaternary animals under various Quaternary environments， which provide a modal for the adaptation of human in greenhouse periods.

Key Words： Quaternary； Climate； Geomicrobes； Speleothem； Peat

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