The past, present and future of palynology in China-Concentrate on Quaternary palynology

Abstract

Palynology is a branch of botany with an increasingly important role in the development of modern nature science. It was originally established in Europe during the early twentieth century and has flourished in China since the 1950s. This paper discusses the development of palynology in China from the historical, contemporaneous, and future perspectives. Specifically, we focus on the development of Quaternary palynology since 1979. Quaternary palynology involves six research fields: plants and environment, Loess Plateau, ocean, the uplift of the Tibetan Plateau, global climate change, and environmental archaeology in this paper. Palynologists who study environmental changes mainly focus on the relationships among pollen, vegetation, and environment. The high-resolution analyses of pollen records in the surface soil and sediment profiles of Loess Plateaus have promoted the development of information about paleovegetation and paleoenvironment and enabled the comparison of past climate changes and effects of human activities with global changes. By analyzing pollen data from surface water samples and marine drilling cores, palynologists have made significant progress in elucidating the high-resolution evolutionary history of paleovegetation, paleoclimate, and paleomonsoon in South China Sea and its surrounding regions on the time scales of several million years. Such progress has benefitted research on global sea level changes. The uplift of the Tibetan Plateau has been a hot area of research for several years. Palynologists have explored the vegetational, climatic, and environmental features of different periods, such as the Late Glacial, the Last Glacial Maximum, the Younger Dryas, and the Holocene Megathermal, to reveal the mechanism and process of the uplift of the Tibetan Plateau. The application of Quaternary palynology to environmental archeology not only facilitates understanding of the needs of the economic life and food structure of ancestral humans, the evolution of paleoenvironment and the rise and fall of culture, but also promotes current research on the origin of human, agricultural and civilization. Although Quaternary palynology has made remarkable achievements in many research fields, three problems require urgent solutions. First, the low magnification and resolution of optical microscopy complicate palynological identification on the species level and introduce a degree of uncertainty to the reconstruction of paleovegetation, paleoenvironment and paleoclimate. Second, pollen does not show a simple linear relationship with vegetation. Thus, a reliable pollen-vegetation relationship model remains to be established. Third, research on modern pollen processes, which includes pollen production, transportation, source, deposition, and preservation, has a crucial role in the correct explanation of pollen data and quantitative reconstruction of the paleovegetation and paleoenvironment. Global changes and the impact of environmental evolution have provided excellent opportunities and new challenges for the development of Quaternary palynology in the new century. These opportunities and challenges are as follows: First, the accuracy of pollen identification must be improved to establish a reliable pollen-vegetation relationship model. Second, systemic theoretical studies on modern pollen processes, such as pollen production, transportation, source, deposition, and preservation, should be conducted using surfaces, atmosphere, water, and rock as media. Third, the reconstruction of paleovegetation and paleoclimate from the qualitative and quantitative analyses of high-resolution pollen assemblages should receive additional efforts. Pollen records should be analyzed using various mathematical methods. Finally, to distinguish the role of climate change and human activities in vegetation and climate dynamics, human land use data, surface and fossil pollen data, and meteorological data can be combined to quantify paleovegetation and land use patterns using appropriate mathematical models. Therefore, only by relying on the integration of multidisciplinary data and academic cooperation with colleagues at home and abroad can we further improve the Quaternary palynological research in China and better serve the needs of our society and national strategies.