Strong coupling of the East Asian summer monsoon and hydroclimate footprints during 53–47 ka

Imprints of Millennial-Scale Monsoonal Events during the MIS3 Revealed by Stalagmite δ13C Records in China

“…Since a cold and wet climate is favorable for the growth of C3 vegetation and a warm and dry climate is favorable for the growth of C4 vegetation, the abundance and climatic conditions of C3 and C4 vegetation can be inferred from stalagmite δ 13 C. In addition, Genty et al [41] believed that stalagmite δ 13 C can be used as an indicator of overlying biomass changes on the millennial timescale based on a study of the Villars Cave, thus reflecting the improvement or degradation in the ecological environment. Obviously, due to high correspondence between vegetation, biomass changes and climate factors (temperature and humidity), stalagmite δ 13 C can reflect climate change to a certain extent [23,26,27]. At the same time, various factors related to soil CO 2 have the same effects on stalagmite δ 13 C; that is, under good climate conditions, dense vegetation, large biomass and an increased C3/C4 ratio will lead to lighter δ 13 C, and vice versa [44].…”

“…In addition, during the last glacial period, the stalagmite δ 13 C of Hulu Cave reflected the "damping effects" on the millennial timescale, and the reconstructed EASM precipitation changes based on this sequence can complement the Hulu δ 18 O records, indicating changes in the monsoon intensity [25]. In northern China, speleothem δ 13 C is mainly interpreted as the soil microbial activity and vegetation associated with changes in soil moisture and temperature [19,23]. Li et al [19] also suggested that cave δ 13 C records are a sensitive and reliable indicator of the EASM rainfall amount, while δ 18 O is an indicator of changes in the phase of the EASM.…”

“…[21]. Recently, reconstruction work has shown that stalagmite δ 13 C records have great potential for revealing changes in the paleoclimate and paleoenvironment, and to a certain extent can make up for the deficiency that stalagmite δ 18 O cannot indicate local environmental changes [19,[22][23][24]. For example, Shennong speleothem δ 13 C is suggested to be controlled by vegetation density, and during the early mid Holocene, a long-term calcite δ 13 C indicates a gradual increase in precipitation [24].…”