The Application And Improvement Of Phytolith Analysis Method

Phytoliths are microscopic mineralized bodies formed in living plants. Monosilicic acid is brought into the plant through the uptake of water and this precipitates to form opaline silica within and between cells. Since phytoliths can create replica of the plant cell bodies, they may be identified to certain genus or species in respect to their plant tissue background and their shape, size, ornaments, cell orientation and other anatomical features. They serve as efficient clues to paleo-environmental reconstruction, agricultural activities and human activities through analysis and interpretation of phytolith assemblages from various sediments. Since the 1970s, phytolith analysis has been a fast developing discipline in archaeology field. In recent years, more and more results based on the phytolith analysis are reported especially in pre-historical agricultural archeology and paleo-environmental archeology. With the progress of phytolith analysis, its unique and un-substitutable advantage has been broadly recognized. However, it is obvious that the phytolith analysis method is subjective and not well systemized, which has become the bottle neck of phytolith analysis and its application. It becomes more and more important and urgent to find new approach to solve these problems.In the first chapter, based on the previous research results, we first summed up basic concepts and unique advantages of phytolith analysis. Then, we review the short history of phytolith research and the current research situation and problems of phytolith analysis in the archaeology. Finally, we summarize the research content of this thesis.In the second chapter, we summarize the state of art phytolith analysis methods. The summary of each method cover the details including collecting phytolith samples and identifying samples in the laboratory. This chapter also introduced the newly developed phytolith analysis method and the actual advantages and disadvantages of these methods. In addition, this chapter concluded drawbacks of current phytolith analysis method; thereby illuminate possible new approaches to solve these problems.In the third chapter, we introduce our phytolith analysis method and results of samples from Heying site and Yantai site. The excavation of Heying site is the first large-scale archeological excavation of Shang-Zhou relics in the southeast region. This excavation provides many precious artifacts, and reveals various worship activities outside the central Shang-Zhou culture. Phytolith analysis of those samples of T1105 from Heying site in the cultural Layer of Shang-Zhou Period reveals valuable agricultural information. There are four distinct morpho-types that, when combined together, are diagnostic feature of cultivated rice(Oryza satlva).The four morpho -types are (a) Rice husk multi-cell panel; (b)double-peaked husk cell; (c) scooped bilobes from the rice leaf; (d) typical fan-shaped bulliform from rice leaf. All the four morpho-types prove that rice was ever planted. Appearance of a great deal of rice silica in any cultural layers, implies that during Shang-Zhou Period rice had been grown on a large scale in the surrounding area. Another proof of wheat plantation is that we find a kind of characteristic phytolith similar to the dendriform or silicified wheat husk reported by Arlene Miller Rosen and Terry B. Ball. From the evidence above, we can estimate that there were domesticated agricultural activities in Heying site at that time. Especially, recovery of some cut phytoliths indicates the presence of threshed grass stems from cultivated cereals in Heying site. It indicates that the bladed threshing sledge was used in ShangZhou Dynasties of China. It is expected to prove the type of agricultural production tools in the ShangZhou Dynasties. It indicates the information of ShangZhou crops harvested and processed forms. Yantai site is a typical Huaiyi ethnic site. From the phytolith evidence, we can estimate that there are domesticated rice and wheat cultivation activities in Yantai site at that time. In addition, samples with the large number of charcoal show that human combusted plants frequently. From the phytolith analysis of these two sites, it is very important for us to understand the economy, society and culture of Shang-Zhou period.In the fourth chapter, we try to get environmental information by analyzing soil samples from Huanglong cave site, Heying site and Yantai site. Huanglong cave site is a valuable late Pleistocene ancient human site. It is the first time that 100 - 50 ka human fossils were unearthed in China. We make a comparison of differentphytoliths' percentages which give clues to the environment. The predominance of some specific phytolith assemblages indicates the Huanglong cave site's environment should be warm. Furthermore, the fourth layer indicates environment is from the semi-arid climate to warm with plenty of rainfall of good forest vegetation. Such environment is suitable for human life. Meantime the predominance of some specific phytolith assemblages indicate the Heying site and Yantai's environment during Shang-Zhou Period should be warm and moist though slightly cooler climate of early Western Zhou Dynasty. So it is not difficult to understand that this region had a higher level of agricultural production with such geographical environment. The objectives of this current research are to examine the utility of opal phytolith studies in reconstruction of the vegetation history of an area and as a tool which will aid in interpretations of man's adaptation to this environment.In the fifth chapter, we apply three-dimension image reconstruction in phytolith research. We reconstruct three-dimension image of phytolith from two-dimension photos from Scanning electron microscopy and optical microscopy respectively. Such three-dimension image reconstruction method can not only greatly improve the efficiency but also reduce the subjectivity of phytolith measurement. We also can facilitate the identification of various forms and statistics by using EFI deep panoramic photo. All these novel methods can lead the phytolith research to a more standardized and systematic direction.