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According to the vegetation investigation and pollen analysis of surface samples sampled along a precipitation gradient of the Northeast China Transect (NECT), several pollen taxa, including Pinus, Betula, Quercus, Tilia, Acer, Ulmus, Artemisia, Chenopodiaceae, Gramineae and Cyperaceae, were chosen to make the regression and correlation analyses. The results indicated that there exists a close relationship between vegetation and pollen taxa in surface samples. The regression parameters for ten taxa in the forests in the eastern part of NECT were different from those in the steppes in the western part. Pinus, Betula, Artemisia and Chenopodiaceae, which have large slope and y-intercept terms, were over-representative taxa. Acer, Gramineae and Cyperaceae, which have small slope and y-intercept terms, were under-representative taxa. Quercus, Tilia and Ulmus whose slope terms have negative correlation with y-intercept terms were equi-representative taxa. The pollen taxa with large slope or large y-intercept terms have small variability coefficients, implying that the slope and y-intercept terms for these pollen taxa are of high accuracy in the estimation of plant abundance from pollen frequencies. Keywords: pollen taxa in surface soil, vegetation, regression parameters (slope term and y-intercept term), representation, Northeast China Transect (NECT).The fossil pollen records are important for reconstructing palaeobiome in global change studies, but it is very complicated to transform fossil pollen data to the accurate estimation of past vegetation [1] . The quantitative relationships between the vegetation and pollen taxa, including Pinus, Betula, Quercus, Tilia, Acer, Ulmus, Artemisia, Chenopodiaceae, Gramineae and Cyperaceae, are essential in reconstructing the past vegetation history in the Holarctic region [2,3] . The former studies mainly focused on the arboreal pollen; little has been done on the herbaceous pollen and the comparison of quantitative relationships between pollen and vegetation among different vegetation types [4,5] . Based on the vegetation investigating and surface sampling along the Northeast China Transect (NECT) [6] , using correlation and regression analyses as tools, we studied the quantitative characteristics of several common pollen taxa and compared the regression parameters of a pollen taxon sampled from different types of vegetation. The application of the results in reconstructing the vegetation history is discussed. Methods( ) Vegetation investigating and surface sampling.The NECT, extending from the Changbai Mountains in Jilin Province to Erenhot in the Inner Mongolia Autonomous Region, is situated between longitudes of 112°E and 130°30′E and latitudes of 42°N and 46°N. The transect was set along the central line of 43°30′N. It is 1 600 km long from the east to the west and 300 km broad from the south to the north, and has a strong east-west gradient of precipitation. The global position system (GPS) was used for location in the field survey. 30 stands were chosen for vege...

The well-preserved Maoshan paddy fields (4700-4300 BP) were built on an intermediate landscape between the foothills and alluvial plain of the Lower Yangtze River. Despite several interdisciplinary research, there has been a lack of detailed environmental and ecological data to contextualise the reconstructed rice farming practices within a wider paleo-environmental background. Our research provides key information on the chronology, vegetation, and long-term hydrological fluctuations at and surrounding the paddy fields. Our 14C and OSL dates show that the initial occupation began at around 5740 ± 140 cal. BP, and the paddy fields were built at around 4675 ± 145 cal. BP and were in use continuously until around 4000 cal. BP. Our pollen, diatom and phytolith data shows that whilst the vegetation in the field was sensitive to changes caused by water management and rice farming, the ecological system surrounding the fields was relatively stable. We suggest that this high frequency of in-field vegetation changes was closely related to intensifying water management for rice farming. This thesis is supported by our geophysical and geochemical analyses of bulk sediments, which shows that the steady build-up of the alluvial sequence was punctuated by several short-term episodes of high-energy surface runoff, including strong flushing in of sandy sediments into the fields perhaps through irrigation activities. Our paleo-ecological and geoarchaeological investigation at Maoshan permits an overview of the development of rice farming and intensifying water management practices in a wider environmental context and offers significant insights to the ongoing debate on the wet-dry dichotomy of early rice farming.