Impact of Abrupt Late Holocene Monsoon Climate Change on the Status of an Alpine Lake in North China

Abstract

The late Holocene is generally regarded as an interval of monsoon recession and decreased precipitation in North China. However, the extent to which this affected the status of lakes in North China is unclear. In the study, we analyzed multiple proxies (δ13C, magnetic susceptibility [χlf], and exogenous element concentrations) from Lake Mayinghai, an undisturbed alpine lake in North China. We also compared the results with previously published paleoenvironmental records from the Chinese Loess Plateau. We aimed to determine the extent of the influence of variations in the East Asian summer monsoon (EASM) on the status of Lake Mayinghai during the late Holocene. The results demonstrate that negative δ13C values at Lake Mayinghai correspond to high sedimentary tree pollen content and high reconstructed precipitation, indicating that variations in δ13C likely reflect variations in vegetation and the EASM in North China. A comparison of the δ13C record with other proxies from the same core reveals an abrupt change in the EASM at ~3 kyr before present (BP), which is also evident in other regional climate records from the Chinese Loess Plateau. The rapid decline in EASM intensity at ~3 kyr BP is also consistent with changes in the status of Lake Mayinghai, Lake Gonghai, Lake Ganhai, and Lake Daihai, in that these lakes underwent an abrupt retreat after 3 kyr BP, demonstrating that the rapid decline in EASM intensity at ~3 kyr BP had a large impact on lake evolution in North China.

Elemental data for Gonghai Lake sediments show significant effects of human activities on weathering processes after 1550 CE

“…Among them, Si, Al, Fe and K mainly exist in silicate minerals, which account for most of the mass of the sediments (Shen et al, 2010). Trends of their concentration-depth plots are generally similar, and they are also similar to the plot for Ti, an element known to be refractory to chemical weathering (Figure 7E, Shen et al, 2010;Cheng et al, 2020). These are also supported by their Pearson's coefficients and significance levels (Figures 8A-D).…”

Synergistic warming- and catchment-driven mid-Holocene cyanobacterial development: Pigment evidence from shallow eutrophic Lake Mayinghai on the Chinese Loess Plateau

“…A 1,490 cm-long core (MYH14B) was retrieved from the deepest part of Lake Mayinghai (Figure 1B) using UWITEC piston coring equipment from the lake ice in January 2014. An age-depth model was developed based on radiocarbon dating of 18 plant macrofossils and two charcoal fragments (see Supplementary Material), which improves the age model published in Cheng et al (2020). Radiocarbon dates were measured at Beta Analytic Inc. (United States).…”

“…Comparison of Holocene pigment data from Lake Mayinghai (A-C) with Ti/Ca (D) (Shen et al, 2018;Cheng et al, 2020) and C/N (E) (Cheng et al, 2020;Li et al, 2020) from the same core, terrestrial vegetation biomes from nearby Lake Gonghai (F) (Xu et al, 2017), mean annual precipitation in northern China (mainly East Asian summer monsoon precipitation) (G) (Chen et al, 2015) and global mean annual temperature (H) (Kaufman et al, 2020).…”

“…Although the C/N ratio (Cheng et al, 2020;Li et al, 2020) shows that there was no clear change in terrestrial organic input during the mid-Holocene (Figure 4E), the Ti/Ca ratio, an excellent proxy for terrestrial siliciclastic input (Shen et al, 2018;Cheng et al, 2020), shows that there was fluctuating but generally higher inorganic elemental input during the mid-Holocene (Figure 4D). This may be linked to high organic matter decomposition and high chemical weathering during the process of soil development under optimal climatic conditions.…”

Holocene precipitation hydrogen isotopic values on Nilgiri Plateau (southern India) suggest a combined effect of precipitation amount and transport paths

“…Precipitation reconstruction based on the core retrieved from (g) Tianchi lake and (h) Gonghai lake (Chen et al, 2017). (i) δ 13 C record of Mayinghai lake sediments (Cheng et al, 2020). (j) δD record of Qinghai lake sediments (Thomas et al, 2016).…”