Since Homo sapiens appeared,the planet has experienced continuing environmental changes[1,2].In 2000,Crutzen and Stoermer[3]systematically analysed the global changes caused by human activity over the previous 300 yea...Since Homo sapiens appeared,the planet has experienced continuing environmental changes[1,2].In 2000,Crutzen and Stoermer[3]systematically analysed the global changes caused by human activity over the previous 300 years and suggested that the Holocene epoch ended in the 1750s and a new geological age,the Anthropocene,began.Afterwards,the Anthropocene drew a lot of attention from both scientific community and the general public.The recognition and placement of the Anthropocene/Holocene boundary has been a subject of heated debates over the past two decades.At the 35th International Geological Congress(2016;IGC),the Anthropocene Working Group(AWG)recommended the Anthropocene to be formalised with an epoch rank,with the 1950s as its lower boundary[4].展开更多
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....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(δ^18O,δ^13C)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 theδ^18O and trace elements in the stalagmite suggest they are reliable precipitation indexes.Theδ^13C 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 theδ^13C record was observed since the 15th century,resulting inδ^13C values from–7.7‰to–1.6‰in the next four centuries.This unprecedentedδ^13C 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.展开更多
基金supported by the Shaanxi Science Fund for Distinguished Young Scholars (2018JC-023)the National Natural Science Foundation of China (41842053)+1 种基金the Youth Innovation Promotion Association (2012295)International Partnership Program (132B61KYSB20170005) of Chinese Academy of Sciences
文摘Since Homo sapiens appeared,the planet has experienced continuing environmental changes[1,2].In 2000,Crutzen and Stoermer[3]systematically analysed the global changes caused by human activity over the previous 300 years and suggested that the Holocene epoch ended in the 1750s and a new geological age,the Anthropocene,began.Afterwards,the Anthropocene drew a lot of attention from both scientific community and the general public.The recognition and placement of the Anthropocene/Holocene boundary has been a subject of heated debates over the past two decades.At the 35th International Geological Congress(2016;IGC),the Anthropocene Working Group(AWG)recommended the Anthropocene to be formalised with an epoch rank,with the 1950s as its lower boundary[4].
基金supported by the National Natural Science Foundation of China(Grant No.41991252)the Strategic Priority Research Program(Grant No.XDB40000000)+4 种基金the International Partnership Program(Grant No.132B61KYSB20170005)of Chinese Academy of Sciencesthe National Natural Science Foundation of China(Grant No.41888101)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)the Belt&Road Center for Climate and Environment Studies of IEECAS。
文摘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(δ^18O,δ^13C)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 theδ^18O and trace elements in the stalagmite suggest they are reliable precipitation indexes.Theδ^13C 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 theδ^13C record was observed since the 15th century,resulting inδ^13C values from–7.7‰to–1.6‰in the next four centuries.This unprecedentedδ^13C 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.
