【作者】 汪建君；

【导师】 孙立广； 陈立奇；

【作者基本信息】 中国科学技术大学 ， 环境科学， 2007， 博士

【摘要】 第一篇生物标志物在全球变化和古环境、古气候的研究中，有极为广泛而成功的应用。但是大多数生物标志物的研究都集中在对古植被的研究，而动物由于活动范围广，较难在沉积物中留下稳定的痕迹，因而难以形成连续而定量的信息。但是作为生态系统的重要组成部分，动物对环境变化的响应相对植物来说更为灵敏；动物对植被的影响也有可能改变植被对环境变化的响应。历史时期动物活动信息是古生态乃至古气候研究重要但是薄弱的一环。本文选取位于高纬度的南极长城站相邻区域典型无冰区的阿德雷岛企鹅聚居地、北极斯瓦尔巴群岛新奥尔松地区海鸟聚居地、位于低纬度的西沙群岛东岛的鸟岛和中纬度的人类古文明遗址安徽蒙城尉迟寺等四地的沉积物进行分析，应用多学科交叉的研究方法，用微观生物地球化学记录去探索宏观的生态环境变化的主题。涉及的主要内容及研究结果如下：1．利用醇类生物标志物恢复南极生态发展历史我们利用粪便甾醇和脂肪醇恢复了阿德雷岛2，400年企鹅数量和不同植被丰度的变化。这是应用粪便甾醇首次在沉积物中连续定量地恢复了地史时期动物种群的变化。历史时期企鹅数量和喜粪藻、苔藓、地衣的变化曲线表明这三种植物对企鹅数量变化的有不同的响应。喜粪藻对企鹅粪的依赖较强，随企鹅种群数量变化而变化：苔藓对土壤要求不高，其丰度变化和企鹅数量变化的相关性小些；地衣与企鹅数量的变化基本上呈反相关。我们的结果表明企鹅数量变化与植被繁盛存在着响应，是有规律可循的，在时间与空间上有着系统的联系。2．北极斯瓦尔巴群岛新奥尔松地区海鸟聚居地的物源研究北极地区拥有大量的煤资源，斯瓦尔巴地区的采煤等经济活动早在20世纪初就已经开始。采自煤矿周围的鸟粪聚居地的沉积物有机烷烃组分中的UCM、接近于1的CPI、高浓度的姥鲛烷和惹烯都显示沉积物受到三叠纪煤矿风化产物的影响；醇类和酸类则明显表现出生物来源，偶碳优势明显；结合沉积物的岩性特征，基本确定谷甾醇和谷甾烷醇是北极海鸟粪的输入造成的。3．南海西沙鸟类变化的指标和可能的森林火灾西沙东岛的鸟粪土沉积物的结果显示有机质含量丰富，其中当地丰富的植被可能是有机质的重要组成。尽管红脚鲣鸟和企鹅粪便中主要的甾醇都是胆甾醇，但是由于沉积环境不同，沉积物中的粪便甾醇并不相同，西沙鸟粪土层中粪便甾醇以异构粪甾醇为主，而南极的企鹅粪土沉积则以胆甾烷醇为主。我们还在中世纪暖期的沉积物中检测到双芳-脱A-五环三萜烷系列化合物，该系列化合物来自于森林杂草的燃烧，其在东岛鸟粪土层的检出，可能和森林火灾或人类活动有关。4．尉迟寺尉迟寺古文明沉积中人类活动对古温度变化的响应对尉迟寺古文化遗址的堆积剖面的生物标志物研究表明沉该沉积物烷烃的短链部分有降解，在剖面上的部分层位可以检测到粪甾醇和胆甾酸，但是很可能由于人类活动的干扰未形成连续的记录。脂肪酸C_18：2／C₁₈在大汶口文化和龙山文化交替的时间发生突变，与古人类文明受环境、温度变化的学说吻合。5．烷基酰胺的鉴定和环境意义我们在尉迟寺古文化剖面中检测并鉴定了烷基酰胺系列化合物。尉迟寺中烷基酰胺的深度曲线及其对古温度的曲线对比表明，烷基酰胺对古温度变化十分灵敏，其形成和蛋白质，也即与生物活动密切相关，在指示历史时期动物活动方面将是一种极有潜力的生物标志物；由于烷基酰胺性质表明其与生物活动紧密相关，其在粪土层中的检出，也极有可能意味着烷基酰胺在某些区域可以作为粪便（或人类活动）污染的标志物。第二篇气溶胶是环境的重要组成部分，由于气溶胶的气候效应和环境意义，气溶胶越来越为人们所关注。南极作为人类活动影响最小的大陆，其气溶胶的性质和行为对其它区域的气溶胶研究十分重要。我们在自上海到南极的航线上和中山站站区积累了多年的数据，对南极航线和站区气溶胶加深了了解：在1999年11月至2000年4月中国第十六次南极考察、2001年11月至2002年4月中国第十八次南极考察和2002年11月至2003年3月中国第十九次南极考察、2004年11月至2005年4月中国第二十一次南极考察和2003年7月至2003年9月中国第二次北极考察期间，自上海到南极的航线上的气溶胶样品中的甲基磺酸（MSA）浓度在南极沿岸都急遽上升，而北极气溶胶中则未有体现。验证了谢周清、孙立广和本人在2002年提出的企鹅粪很有可能是南极气溶胶中MSA不可忽视的一个来源的假设。我们对中山站1998—2001年三年的气溶胶样品利用中子活化（INAA）分析，表明除海洋和陆源元素之外，Se、Co、Sb、Zn、Cr等几个元素在站区高度富集，透射电镜（TEM-EDX）和扫描电镜（SEM-EDX）的结果也显示了污染颗粒的存在，可能来源于站区的取暖、仪器日常运行以及垃圾处理。更多还原

【Abstract】 ChapterIBiomarkers had been widely and successfully used in global changes, paleoenvironment and paleoclimate studies. Most studies of biomarkers focused on the vegetations information, and it was difficult for the animals to leave their continuous, quantitative information in the sediments since have larger territories and their populations were relatively less than vegetations. The animals were the main components of ecosystem and they might be more sensitive to the climate changes; furthermore the influences of animals to vegetations could disturb the response of the vegetation to the environmental changes.In this study, we have collected four sediments from Ardley Island, Antarctica, Ny-Alesund, Arctica, Dongdao, Xisha and Yuchisi, Middle China. An interdisciplinary approach was employed to study the biogeochemical records on a microcosmic level and explore the paleoenvironmental changes on a macroscopic scale. Main contents and research results are given as follows:1. The evolution of penguin colony by the alcohol biomarkersFecal sterols and n-alkanols were identified to reconstruct historical penguin population and vegetation abundance for the past 2,400 years. The results showed that the fluctuation of penguin population seemed to be a major driving force in the evolution of vegetations of the penguin colony. Moderate penguin population is favorable for coprophilic algae and mosses; but lichen abundances decreased whenever penguin population increased, and vice versa. Results showed that the temporal influences of penguin to the vegetations were consistent with the spatial influences.2. Source of the ornithogenic sediment from Ny-Alesund, ArcticaThe molecular biomarker compositions of ornithogenic sediments （YN）, from Svalbard, Arctic were investigated. The alkanes contained unresolved complex mixtures （UCM）, and relatively higher levels of pristine and retene indicating pollution from the coal mines nearby. The n-alkanols and fatty acids in the sediments with even-to-odd preference might originate mainly from modern biota. The dominant sterol was sitosterol, which is the main sterol found in herbivores feces, indicating that sitosterol might be a marker of input from the birds feces in the sediments.3. Ecosystem of seabirds colonies on Dongdao, Xisha and possible forest fireThe analysis of DY4 sediment in Dongdao Island showed that DY4 was a biogenic sediment core and the vegetation attributed a lot to TOC of the sediment. Although cholesterol is the dominant sterol in both of penguin dropping and Sula Sula （local seabird） dropping, the fecal sterols were different for the sediment for Y2 and DY4, maybe due to different environments. We also detected diaromatic A-noroleananes in sediment core DY4, which should be from the litters burning, and its detection might suggest dry weather and more forest fires at those times.4. Response of paleoculture to paleoclimate changes in Yuchisi, Middle China Archaeological excavation showed that there were two paleoculture: DawenkouCulture （5,050 aB.P.-4,400 aB.P.） and Longshan Culture （4,400 aB.P.-4,000 aB.P.） exited in Yuchisi Site, Mengcheng, Anhui, China. Study of biomarkers of Yuchisi Site showed that short-chain alkanes have degraded. Occurance of corprastanol and bile acids in some depths of the profiles might come from human activities. All the proxies, showed a big change at the substitution layer, especially fatty acid ratio C_18:2/C₁₈, and it seemed that a cold event happened about 4400 years ago, which droved the changes of the cultures.5. Identification of alkyl amides and their environmental significancesWe have identified alkyl amides in the sediment of Yuchisi Site. The profile of alkyl amides and atty acid ratio C_18:2/C₁₈ showed that alkyl amides were sensitive to the paleoclimate changes, and its formation might also be related to the protein and/or biogenic activites. Hence they might be potential biomarkers for paleoenvironment changes and historic animals’ populations. It could also be biomarkers for pollution from human or animal since its detection in fecal sediments. Chapter IIAersols are one of the most important atmospheric components since they are related to the climate, environment and pollution. Antarctica are the most remote continent in the world, and its aerosols are important for understanding aerosols in global and other region. We have accumulated aerosols samples in many years of cruise from Shanghai to Antarctica and in Zhongshan Station. Herein we study the aerosols:Concentrations of Methane Sulphonic Acid in the aserosols of cruises: 16^th Chinese Antarctic Research Expedition （CHINARE） （1999.11-2000.4）, 18^th CHINARE （2001.11-2002.4）, 19^th CHINARE （2002.11-2003.3）, 21^st CHINARE （2004.11-2005.3）, 2^nd Chinese Arctic Research Expedition （2003.7-2003.9） increased sharply near coastal Antarctica, and this did not happen near coastal Arctic.Three years of bulk, high-volume aerosol samples were collected over Zhongshan Station in the Eastern Antarctica. INAA, SEM-EDX and TEM-EDX were applied respectively to obtain various chemical species and physical features for aerosols. A graphical technique were applied to the INAA data and five elements Se、Co、Sb、Zn、Cr were highly enriched in the station aerosols, and they might come from the petroleum burning for power generation, heating and equipment operation. The SEM-EDX and TEM-EDX photo also showed besides sea salt and crustal aerosols, there were particles from biomass burning, showing that human activities has obviously affected on the local environments in Antarctica.更多还原