Applications Of Biomarkers In Paleoecology Reconstruction In Holocene And Characteristics Of Antarctic Aerosols

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.