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This paper describes an assemblage of diverse floodplain facies of reworked loess (facies b, c) in a Middle Pleistocene monsoonal setting of the Hanzhong Basin, central China. The vertical and lateral sedimentary sequences show changing energy conditions. Apart from the highest energy in the channel facies (facies a), a relatively high energy floodplain environment (facies b) prevailed in waterlogged conditions, with small, laterally migrating (sub)channels. Facies b generally interfingers with aggrading horizontal sheets of overbank deposits in alluvial pools and swamps in a floodplain with much lower energy (facies c), in which phases of stability (soil formation) occasionally interrupted overbank deposition. Reworked loess forms the main part of the floodplain deposits. The paleosols are considered to have been formed under low hydrodynamic conditions in an interglacial environment. These interglacial conditions follow the commonly assumed glacial conditions of channel facies a. The sedimentary successions in the floodplain show a recurrent composition and cyclicity between wet and dry floodplain sedimentation terminated by stability with soil formation. The cyclic rhythm of stacked high- and low-energy floodplain sediments is attributed to varied intensity of different hydrodynamic flooding events that may have been due to changing monsoonal rainfall or simple intrinsic fluvial behavior. [ABSTRACT FROM AUTHOR]

This paper examines the dispersal–germination strategy of seeds of 66 native tree species from a seasonal evergreen monsoon rainforest on Hainan Island, China, and assesses correlations among seed germination and phylogeny, dispersal mode and dispersal season. Seeds of 15, 7, 25 and 19 species were dispersed during the warm dry (March–May), rainy (June–September), late rainy (October–November) and cool dry (December–February) seasons, respectively. Berries (16 species), drupes (14 species) and capsules (12 species) were common and represented about 64% of the species. Zoochory was the most common dispersal mode (69.7%) followed by anemochory (16.7%) and autochory (13.6%). More than 65% of species had dormant seeds. Based on germination speed and synchrony, six patterns were recognized: rapid and synchronous germination (13 species), intermediate and synchronous germination (3 species), intermediate and intermediately synchronous germination (24 species), intermediate and asynchronous germination (2 species), slow and intermediately synchronous germination (5 species), and slow and asynchronous germination (19 species). One-way ANOVAs revealed that the variance in germination percentages among species was largely dependent upon phylogeny. The mean and median length of germination (MLG) were largely dependent upon phylogeny, dispersal mode and dispersal season. Anemochorous seeds germinated faster than autochorous and zoochorous seeds. Seeds dispersed in the late dry or early rainy season (March–May) tended to germinate quickly, whereas those dispersed towards the end of the rainy season and into the cool dry season are likely to have a much longer length of dormancy. Correlation analyses indicated that larger seeds germinated faster and had higher germination percentages. [ABSTRACT FROM PUBLISHER]

The East Asian monsoon (EAM) has experienced significant changes over the past 10,000 years that influenced East Asian agricultural development. However, the magnitude and extent of the EAM precipitation fluctuations at 6 ka remain unresolved, owing to uncertainty in individual lake records and substantial variations in the expansion limits in simulations of the mid-Holocene EAM precipitation. Here we present an approach based on multiple lake-level records using the "1D lake level—2D lake area—3D catchment hydrology" model to reconstruct the precipitation patterns in northern China, and to further quantify the extent of the EAM precipitation expansion in the mid-Holocene relative to today. The precipitation reconstructions suggest an ~550–1100 km northward expansion and an ~530–840 km westward migration of the EAM at 6 ka. At that time, the EAM precipitation domain covered over 6 million square kilometers. Thus, this approach mitigates the uncertainty and arbitrariness of reconstructions of the limit of the EAM precipitation fields and provides a benchmark for future climate modeling studies. [ABSTRACT FROM AUTHOR]