Evaluating anthropogenic impacts on regional vegetation changes during historical time is not only important for a better understanding of the Anthropocene but also valuable in improving the vegetation-climate models. In this study, we analyzed stable isotopes (δ18O, δ13C) and trace elements (Mg/Ca, Sr/Ca) of a stalagmite from Huangchao Cave in central Shandong, northern China. 230Th and AMS14C dating results indicate the stalagmite deposited during 174BC and AD1810, with a hiatus between AD638 and 1102. Broad similarities of the δ18O and trace elements in the stalagmite suggest they are reliable precipitation indexes. The δ13C of the stalagmite, a proxy of vegetation change, was generally consistent with local precipitation and temperature variations on a centennial-scale before the 15th century. It typically varied from −9.6‰ to −6.3‰, indicating climate controlled C3 type vegetation during this period. However, a persistent and marked increasing trend in the δ13C record was observed since the 15th century, resulting in δ13C values from −7.7‰ to −1.6‰ in the next four centuries. This unprecedented δ13C change caused by vegetation deterioration cannot be explained by climate change but is fairly consistent with the dramatically increasing population and farmland in Shandong. We suggest that the increasing deforestation and reclamation in central Shandong began to affect vegetation in the mountain region of central Shandong since the 15th century and severely destroyed or even cleared the forest during the 16th–18th century.
Bibliographical noteFunding Information:
We thank the two anonymous reviewers for their constructive suggestions. This work was supported by the National Natural Science Foundation of China (Grant No. 41991252), the Strategic Priority Research Program (Grant No. XDB40000000), the International Partnership Program (Grant No. 132B61KYSB20170005) of Chinese Academy of Sciences, and the National Natural Science Foundation of China (Grant No. 41888101). It was also partly supported by the USA National Science Foundation (Grant Nos. 0908792, 1211299 & 1702816 to R. Lawrence EDWARDS and Hai CHENG), the 111 Program of China (Grant No. D19002) and the Belt & Road Center for Climate and Environment Studies of IEECAS.
- 16th century
- Human activity
- Stable isotopes
- Trace elements