Reconstructing Mid- to Late Holocene East Asian Monsoon Variability in the Jingpo Lake, Northeastern China

Abstract

The Northeastern China involves complex interactions between the East Asian monsoon (EAM) circulation and the polar climate system, and plays a significant role as the bridge communicating low and high latitude climatic processes. High-resolution multi-proxy analysis of a robust AMS 14 C dated lacustrine sediment core recovered from Jingpo Lake in northeastern China provides a detailed history of East Asian monsoon (EAM) variability and vegetation changes during the Midto Late Holocene. The multi-proxy results show that the climate was relatively warm and humid during the period from 5100 to 3600 cal. yr BP, cool and dry between 3600 and 2100 cal. yr BP, and a strengthening of the EAM intensity during the period of 2100 to 150 cal. yr BP. After 150 cal. yr BP, the multi-proxy results reflecting the Jingpo Lake region is affected by intensive human activities. Our findings indicate that variability of the EAM during the Mid-to Late Holocene on multi-decadal to centennial scale are forced by changes in both solar output and oceanic-atmospheric circulations. Furthermore, we have found the evidence that abrupt climate changes coincides with the collapse or the beginning and the chaotically divided of some Chinese dynasties, which will need further research on the relationship between climate and human cultural changes.

Effects of Organic Wastes on Soil Organic Carbon and Surface Charge Properties in Primary Saline-alkali Soil

“…Also, there was a positive correlation between HFOC, Fr-LFOC, and Oc-LFOC (p < 0.05). Rong and Ji [49] also found out that tree litter increases the carbon content and its components in the soil. Guan, Liu, Zhang, et al [50] returned charred and uncharred maize straw to the field and reported that both straws could increase the soil organic carbon content and its components.…”