Late Holocene mangrove development and response to sea level change in the northwestern South China Sea

Response of Mangrove Development to Air Temperature Variation Over the Past 3000 Years in Qinzhou Bay, Tropical China

“…Based on the ratio of the depth intervals to the time spans, the sedimentation rates of the core sections 0-6, 6-27, 27-57, 57-81, 81-101, and 101-149 cm were about 21.1, 36.4, 56.0, 72.1, 48.0, and 47.3 cm kyr −1 , respectively (Figure 2), with a mean value of 47.12 cm kyr −1 . The sedimentation rates in core Q43 are similar to the vertical accretion of mangrove forests reported by other researchers in tropical China (Meng et al, 2017;Xia et al, 2019), Puerto Rico (Cohen et al, 2016), and the Amazon Region (França et al, 2013).…”

“…However, rapid changes in the RSL can upset this balance, leading to a decline in or even the disappearance of mangrove habitats. Previous studies on worldwide mangrove development during the entire Holocene have shown that the landward migration and communities succession of mangrove forests occurred from the Early to Middle Holocene, the period in which the RSL rose quickly FIGURE 5 | Comparisons between changes in mangrove-derived organic matter (MOM) and natural and anthropogenic records: (A-C) variations in MOM from the Q43 (this study), YLW02 (Meng et al, 2017), and HXL (Xia et al, 2019) cores, respectively, in Guangxi coasts; (D-E) temperature anomaly in China (Hou and Fang, 2011) and the Northern Hemispheric (Ljungqvist, 2010); (F) stalagmite δ 18 O records from Dongge Cave, SW China (Wang et al, 2005); (G) variation in the global sea level over the past 3,000 cal yr BP (Kemp et al, 2018;Miller et al, 2020) (H) population changes in Guangdong Province (logarithmic (base 10) scale (Zhao and Xie, 1988;Huang et al, 2018)); (I) Chinese dynasties and climatic stages (Zhu, 1973;Ge et al, 2014). The latter includes the Zhou Dynasty cold period (ZDCP), Qin-Han warm period (QHWP), Wei-Jin cold period (WJCP), Sui-Tang warm period (STWP), Song-Yuan warm period (SYWP), Ming-Qing cold period (MQCP), and Anthropocene warm period (AWP).…”

“…However, mangrove forests have the capacity to resist changes in hydrodynamic conditions (e.g., increased wave energy) owing to their dense and complex aerial root systems (e.g., such as prop roots and pneumatophores) (Duke et al, 2007). Previous studies on the Qinzhou and Yingluo bays collectively indicate that mangrove development was little influenced by the hydrodynamic conditions during the Late Holocene (Meng et al, 2017;Xia et al, 2019). Thus, this factor does not require excessive consideration in this study.…”

“…The world at present is characterized by a rapid sea level rise, rapid warming, frequent extreme climate events, and an increasing population. Therefore, to predict the fate of mangrove ecosystems under this rapidly changing environment, it is imperative to understand how they have changed or disappeared in the past (Valiela et al, 2001), by reconstructing historical mangrove dynamics through useful indicators recorded in sediments (Gonneea et al, 2004;Ellison, 2008;França et al, 2013;Cohen et al, 2016;Meng et al, 2017;Xia et al, 2019;Vaughn et al, 2021).…”

“…Tropical or subtropical Asia, a region that features a unique climate system (Asian monsoon) and a long history of human civilization, holds most of the world's mangrove forests along its FIGURE 1 | Locations of the (A) sediment core Q43 in Qinzhou Bay, (B) northern Gulf of Tonkin, (C) tropical China. The referenced sites contain HXL in Qinzhou Bay (Xia et al, 2019), YLW02 in Yingluo Bay (Meng et al, 2017), and Dongge Cave in SW China (Wang et al, 2005). GTSC: Gulf of Tonkin Surface Current (Liu et al, 2016).…”