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A comprehensive and integrative view of East Asian monsoon evolution during the Holocene is still under debate, and additional high-resolution proxy records from climatically sensitive locations are requisite to solve this complex issue. In this paper, we present three well-dated mud/peat cores from a paleo-pingo depression in the Sanjiang Plain, a climatically sensitive region to monsoon variation, to reveal the paleoenvironmental history of the wetland and discuss the regional impacts from monsoon evolution. A paleolake developed in the study area before 5.5 ka BP, and a peatland initiated thereafter consequent upon the gradual shrinking of the paleolake. This transition lasted until 4.5 ka BP, when the paleolake changed entirely to a wetland. Considering the prevalent monsoon climate in the Sanjiang Plain, we suggest that the lake-to-wetland transition from 5.5 to 4.5 ka BP indicates a rapid decline of the East Asian summer monsoon in addition to autogenic basin infilling processes. Such a remarkable monsoon weakening event has been documented across northern China, and we associate this with ocean–atmosphere interactions throughout low-latitude regions. [ABSTRACT FROM AUTHOR]

The lotus (Nelumbo nucifera Gaertn.) is the largest aquatic vegetable in Asia. The lotus seedpod (LS) is an inedible part of the mature flower receptacle of the lotus plant. However, the polysaccharide isolated from the receptacle has been less studied. The purification of LS resulted in two polysaccharides (LSP-1 and LSP-2). Both polysaccharides were found to be medium-sized HG pectin, with a Mw of 74 kDa. Their structures were elucidated via GC–MS and NMR spectrum and proposed as the repeating sugar units of GalA connected via α-1,4-glycosidic linkage, with LSP-1 having a higher degree of esterification. They have certain content of antioxidant and immunomodulatory activities. The esterification of HG pectin would have an adverse effect on these activities. Furthermore, the degradation pattern and kinetics of LSPs by pectinase conformed to the Michaelis-Menten model. There is a large amount of LS, resulting from the by-product of locus seed production, and thus a promising source for the isolation of the polysaccharide. The findings of the structure, bioactivities, and degradation property provide the chemical basis for their applications in the food and pharmaceutical industries. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract A high-resolution pollen record in a peat sequence from the Altai Mountains of Xinjiang, China, allows reconstruction of the regional vegetation and climate changes that occurred during the Holocene. Pollen distributions from the sequence indicate that the vegetation community in the Altai Mountains region transitioned through five general phases: forest and desert steppe, wet steppe, desert steppe, steppe, and finally forest and desert steppe. These vegetative phases imply that the regional climate changed from a cold and dry early Holocene to a warmer and wetter early-mid Holocene and then to a cold and rather dry mid-Holocene that was followed by a cool and wet late Holocene and finally by warm and dry conditions for the last millennium. These regional changes in climate are roughly consistent with local changes previously reconstructed from organic geochemical paleoclimate proxies in the same peat sequence by Zhang et al. (2016), but with some minor but important differences that reflect local factors. Regional comparisons reveal that the Holocene climate changes in the Altai Mountains are generally consistent with those of most arid central Asian regions that are influenced mainly by westerlies. However, they are out-of-phase with the climate histories of regions controlled by the Asian monsoons, indicating that the Asian monsoons did not extend to the high-altitude mountain regions of arid central Asia during the Holocene. We postulate that the regional Holocene moisture variations have been mainly modulated by NAO variations that affected transport of water vapor from the North Atlantic Ocean by the westerlies. Moreover, local factors that include topography of the mountains and glacial meltwater events in the high-altitude regions also contributed to the climate changes in the Altai Mountains. In addition, air temperatures related to summer insolation of the Northern Hemisphere might have played an important role in modulating moisture in the region, but only after the local montane ice-sheets had disappeared by the mid-Holocene. Highlights • Pollen records from a peat sequence from Xinjiang Altai Mountains reveal Holocene vegetation changes. • Pollen-based reconstruction of Holocene climate changes in the Altai Mountains. • Comparisons of Holocene climate changes in Altai Mountains with arid central Asian and monsoonal Asian regions. • Explanations proposed for Holocene vegetation and climate changes in the Altai Mountains. [ABSTRACT FROM AUTHOR]