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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]

This paper provides another look at the response of the Asian summer monsoon (ASM) to insolation forcing and oceanic feedback during the Holocene, using a fully coupled general circulation ocean–atmosphere model forced by Earth’s orbital variations. The model results revealed a recurrent circumglobal teleconnection (CGT) pattern in the summertime (June–July–August) mid-latitude circulation of the Northern Hemisphere during the Holocene. The CGT index showed a decreasing trend before ~5 ka BP and a slight increasing trend afterwards, affected by the combined effects of summer insolation, Indian summer monsoon (ISM), North Atlantic and Indian Ocean–western Pacific Ocean sea surface temperature (SST). The CGT showed a close relationship with ASM precipitation and surface air temperature during the Holocene and, therefore, could act as a bridge linking the ASM to insolation, high-latitude forcing (North Atlantic SST), and low-latitude forcing (tropical Ocean SST). We emphasize that the mid-latitude atmospheric circulation has been a key factor for the evolution of the ASM during the Holocene. In addition, the CGT provides a viable explanation for the out-of-phase relationship in the moisture evolution but an in-phase relationship in the speleothem δ18O between arid central Asia and the ISM region during the Holocene. [ABSTRACT FROM AUTHOR]

This paper reconstructs the evolutionary history of the Pearl River delta over the last 9000 years and investigates land-sea interaction in a large deltaic complex which formed under the influence of Asian monsoon climate. Specifically, this research examines the delta evolution in the context of three driving mechanisms: (1) rising sea level that influences the available accommodation space, (2) fluvial discharge as influenced by monsoon climate and (3) human activities that alter sedimentation within the deltaic system. Results reveal that the formation of deltaic sequences was initiated as a consequence of rapid sea-level rise between 9000 and 7000 cal. yr BP. The rate of sea-level rise slowed down markedly around 7000 cal. yr BP and sedimentation switched from transgressive to regressive. Initially, both the progradation of the delta plains near the apex and aggradation of delta front sedimentation in the central and lower parts of the receiving basin were fast owing to strong monsoonal-driven runoff. The progradation rate gradually slowed down between 6800 and 2000 cal. yr BP as monsoonal-driven runoff weakened. Rapid shoreline advances during the last 2000 years were the result of significantly increased human activities, a practice that trapped sediments in the encircled tidal flats along the front of delta plains. The evolutionary history of the Pearl River delta demonstrates the interplay between the three driving mechanisms. [ABSTRACT FROM AUTHOR]

The paper explores the use of Resilience Theory to provide an improved theoretical framework for the analysis of socio-ecological interactions over decadal—millennial timescales. It identifies landscape system behaviour through analysis of proxy records for land use, erosion and monsoon intensity over the past 3000 years in the Erhai lake-catchment system, Yunnan, SW China. Analysis of the records shows the possibility of alternative steady states in the landscape, as expressed by the relationship between land use and erosion. In particular, a period of agricultural expansion ~1400 cal. yr BP triggered rapid gully erosion that led to the formation of an eroded landscape state that has existed since ~800 cal. yr BP to the present day. Comparison of detrended time-series data suggests that over 3000 years erosion and land use should be considered 'slow' processes relative to the 'faster' monsoon intensity and flooding. In the past, the effects of high monsoon variance on flooding have been suppressed by paddy farming and the maintenance of terraced field systems. Mapping the Adaptive Cycle on to the millennial record of land use and erosion suggests that the modern landscape may be approaching a 'conservation' phase characterized by minimum resilience. Such 'historical profiling' of modern landscapes offers a new dimension for hypothesis testing, for the development and testing of simulation models and for the creation of appropriate management strategies. [ABSTRACT FROM AUTHOR]