It is increasingly recognized that human activities-such as crop cultivation and biomass burning-have become dominant drivers of vegetation change, surpassing the influence of climate in many regions. However, the effects of human activities on vegetation change over the past two millennia remains unclear. Here, we present a biomarker record spanning the last two millennia from the Huguangyan Maar Lake in tropical China. The δ13C values of long-chain n-alkanes (nC29–nC33) exhibit two major, abrupt shifts around 220 and 800 CE. Local chronicles documented that sugarcane cultivation began approximately 2000 years ago, with a further expansion after ~630 CE. Sugarcane utilizing the C4 (Hatch-Slack) photosynthetic pathway are isotopically enriched about 12‰ compared with the δ13C for the vegetation in the lake catchment (C3 plant, Calvin-Benson pathway). In addition, previous paleoclimatic records did not show significant changes around these two intervals. Therefore, the two pronounced shifts in long-chain n-alkanes are likely attributable to human migration and the expansion of sugarcane cultivation.
BaiYOuyangTJiaG (2014) Late Holocene human activity inferred from sedimentary n-alkanes and their carbon isotope in the Huguangyan Maar Lake. Tropical Geography34(2): 156–164. (Chinese with English abstract).
2.
BiXShengGLiuX, et al. (2005) Molecular and carbon and hydrogen isotopic composition of n-alkanes in plant leaf waxes. Organic Geochemistry36: 1405–1417.
3.
BlaauwMChristenJA (2011) Flexible paleoclimate age-depth models using an autoregressive gamma process. Bayesian Analysis6: 457–474.
4.
BrayEEEvansED (1961) Distribution of n-paraffins as a clue to recognition of source beds. Geochimica et Cosmochimica Acta22: 2–15.
5.
BushRTMcInerneyFA (2013) Leaf wax n-alkane distributions in and across modern plants: Implications for paleoecology and chemotaxonomy. Geochimica et Cosmochimica Acta117: 161–179.
6.
CaoJChenFChuG, et al. (2024) A persistent coast mode of precipitation in southeast China over the last millennium. Geophysical Research Letters51: e2024GL109379.
7.
CaoXTianFHerzschuhU, et al. (2022) Human activities have reduced plant diversity in eastern China over the last two millennia. Global Change Biology28: 4962–4976.
8.
CastañedaISSchoutenS (2011) A review of molecular organic proxies for examining modern and ancient lacustrine environments. Quaternary Science Reviews30: 2851–2891.
9.
ChengZWengCSteinkeS, et al. (2018) Anthropogenic modification of vegetated landscapes in southern China from 6,000 years ago. Nature Geoscience11: 939–943.
10.
ChuGLiuJSunQ, et al. (2002) The 'Mediaeval Warm Period' drought recorded in Lake Huguangyan, tropical south china. Holocene12: 511–516.
11.
ChuGSunQXieM, et al. (2014) Holocene cyclic climatic variations and the role of the Pacific Ocean as recorded in varved sediments from northeastern China. Quaternary Science Reviews102: 85–95.
12.
ChuGSunQZhuQ, et al. (2017) The role of the Asian winter monsoon in the rapid propagation of abrupt climate changes during the last deglaciation. Quaternary Science Reviews177: 120–129.
13.
CranwellPA (1981) Diagenesis of free and bound lipids in terrestrial detritus deposited in a lacustrine sediment. Organic Geochemistry3(3): 79–89.
14.
CranwellPAEglintonGRobinsonN (1987) Lipids of aquatic organisms as potential contributors to lacustrine sediments—II. Organic Geochemistry11(6): 513–527.
15.
DiefendorfAFFreimuthEJ (2017) Extracting the most from terrestrial plant-derived n-alkyl lipids and their carbon isotopes from the sedimentary record: A review. Organic Geochemistry103: 1–21.
16.
DodsonJLiJLuF, et al. (2019) A Late Pleistocene and Holocene vegetation and environmental record from Shuangchi Maar, Hainan Province, South China. Palaeogeography Palaeoclimatology Palaeoecology523: 89–96.
EllisECGauthierNKlein GoldewijkK, et al. (2021) People have shaped most of terrestrial nature for at least 12,000 years. Proceedings of the National Academy of Sciences of the United States of America118(17): e2023483118.
19.
FickenKJLiBSwainDL, et al. (2000) An n-alkane proxy for the sedimentary input of submerged/floating freshwater aquatic macrophytes. Organic Geochemistry31(7-8): 745–749.
20.
GarcinYSchefußESchwabVF, et al. (2014) Reconstructing C 3 and C 4 vegetation cover using n-alkane carbon isotope ratios in recent lake sediments from Cameroon, Western Central Africa. Geochimica et Cosmochimica Acta142: 482–500.
21.
GeQHaoZZhengJ, et al. (2013a) Temperature changes over the past 2000 yr in China and comparison with the Northern Hemisphere. Climate of the Past9(3): 1153–1160.
22.
GeQZhengJHaoZ, et al. (2013b) General characteristics of climate changes during the past 2000 years in China. Science China Earth Sciences56(2): 321–329.
23.
GriceKMesmayRDGlucinaA, et al. (2008) An improved and rapid 5A molecular sieve method for gas chromatography isotope ratio mass spectrometry of n-alkanes (C8–C30+). Organic Geochemistry39(3): 284–288.
24.
HuangCZengTYeF, et al. (2018) Natural and anthropogenic impacts on environmental changes over the past 7500 years based on the multi-proxy study of shelf sediments in the northern South China Sea. Quaternary Science Reviews197: 35–48.
25.
HuangYFreemanKHEglintonTI, et al. (1999) δ13C analyses of individual lignin phenols in Quaternary lake sediments: A novel proxy for deciphering past terrestrial vegetation changes. Geology27(5): 471–474.
26.
HuJZhouHPengP, et al. (2015) Reconstruction of a paleotemperature record from 0.3–3.7ka for subtropical South China using lacustrine branched GDGTs from Huguangyan Maar. Palaeogeography Palaeoclimatology Palaeoecology435: 167–176.
27.
InglisGNBhattacharyaTHemingwayJD, et al. (2022) Biomarker approaches for reconstructing terrestrial environmental change. Annual Review of Earth and Planetary Sciences50(1): 369–394.
28.
JennyJ-PKoiralaSGregory-EavesI, et al. (2019) Human and climate global-scale imprint on sediment transfer during the Holocene. Proceedings of the National Academy of Sciences of the United States of America116(46): 22972–22976.
29.
JiaGBaiYYangX, et al. (2015) Biogeochemical evidence of Holocene East Asian summer and winter monsoon variability from a tropical maar lake in southern China. Quaternary Science Reviews111: 51–61.
30.
LiQSunQXieM, et al. (2023) Coupled temperature variations in the Huguangyan Maar Lake between high and low latitude. Quaternary Science Reviews305: 108011.
31.
LiTZhouYWursterCM, et al. (2024) Vegetation and precipitation change inferred from the δ13C and δ2H values of n-alkanes from lake sediment from 18 cal ka BP, tropical NE Australia. Quaternary Science Reviews337: 108807.
32.
LiuWYangHWangH, et al. (2015) Carbon isotope composition of long chain leaf wax n-alkanes in lake sediments: A dual indicator of paleoenvironment in the Qinghai-Tibet Plateau. Organic Geochemistry83–84: 190–201.
33.
MaTRolettBVZhengZ, et al. (2020) Holocene coastal evolution preceded the expansion of paddy field rice farming. Proceedings of the National Academy of Sciences of the United States of America117(39): 24138–24143.
34.
MeyersPA (2003) Applications of organic geochemistry to paleolimnological reconstructions: A summary of examples from the Laurentian Great Lakes. Organic Geochemistry34(2): 261–289.
35.
MingramJNegendankJFWBrauerA, et al. (2007) Long cores from small lakes—recovering up to 100 m-long lake sediment sequences with a high-precision rod-operated piston corer (Usinger-corer). Journal of Paleolimnology37: 517–528.
36.
MingramJSchettlerGNowaczykN, et al. (2004) The Huguang maar lake—a high-resolution record of palaeoenvironmental and palaeoclimatic changes over the last 78,000 years from South China. Quaternary International122(1): 85–107.
37.
MottlOFlantuaSGABhattaKP, et al. (2021) Global acceleration in rates of vegetation change over the past 18,000 years. Science372(6544): 860–864.
38.
NaafsBDAInglisGNBlewettJ, et al. (2019) The potential of biomarker proxies to trace climate, vegetation, and biogeochemical processes in peat: A review. Global and Planetary Change179: 57–79.
39.
NaeherSCuiXSummonsRE (2022) Biomarkers: Molecular tools to study life, environment, and climate. Elements18(2): 79–85.
40.
O’LearyMH (1981) Carbon isotope fractionation in plants. Phytochemistry20(4): 553–567.
41.
O’LearyMH (1988) Carbon Isotopes in Photosynthesis: Fractionation techniques may reveal new aspects of carbon dynamics in plants. BioScience38(5): 328–336.
42.
PAGES 2k Consortium (2013) Continental-scale temperature variability during the past two millennia. Nature Geoscience6(5): 339–346.
43.
RaoZChenFZhangX, et al. (2012) Spatial and temporal variations of C3/C4 relative abundance in global terrestrial ecosystem since the last glacial and its possible driving mechanisms. Chinese Science Bulletin57(31): 4024–4035.
44.
RaoZGuoWCaoJ, et al. (2017) Relationship between the stable carbon isotopic composition of modern plants and surface soils and climate: A global review. Earth-Science Reviews165: 110–119.
45.
RaoZJiaGLiY, et al. (2016) Asynchronous evolution of the isotopic composition and amount of precipitation in north China during the Holocene revealed by a record of compound-specific carbon and hydrogen isotopes of long-chain n-alkanes from an alpine lake. Earth and Planetary Science Letters446: 68–76.
46.
RaoZZhuZWangS, et al. (2009) CPI values of terrestrial higher plant-derived long-chain n-alkanes: a potential paleoclimatic proxy. Frontiers of Earth Science in China3(3): 266–272.
47.
ReimerPJAustinWENBardE, et al. (2020) The IntCal20 Northern Hemisphere radiocarbon age calibration curve (0–55 cal kBP). Radiocarbon62(4): 725–757.
48.
RieleyGCollierRJJonesDM, et al. (1991) Sources of sedimentary lipids deduced from stable carbon-isotope analyses of individual compounds. Nature352(6334): 425–427.
49.
RolettBVZhengZYueY (2011) Holocene sea-level change and the emergence of Neolithic seafaring in the Fuzhou Basin (Fujian, China). Quaternary Science Reviews30(7–8): 788–797.
50.
RommerskirchenFEglintonGDupontL, et al. (2003) A north to south transect of Holocene southeast Atlantic continental margin sediments: Relationship between aerosol transport and compound-specific δ13C land plant biomarker and pollen records. Geochemistry Geophysics Geosystems4(12): 1101.
51.
SachseDRadkeJGleixnerG (2006) δD values of individual n-alkanes from terrestrial plants along a climatic gradient – Implications for the sedimentary biomarker record. Organic Geochemistry37(4): 469–483.
52.
ShengMWangXZhangS, et al. (2017) A 20,000-year high-resolution pollen record from Huguangyan Maar Lake in tropical–subtropical South China. Palaeogeography Palaeoclimatology Palaeoecology472: 83–92.
53.
ShenJJonesRTYangX, et al. (2006) The Holocene vegetation history of Lake Erhai, Yunnan province southwestern China: The role of climate and human forcings. Holocene16(2): 265–276.
54.
StrongDFleckerRValdesPJ, et al. (2013) A new regional, mid-Holocene palaeoprecipitation signal of the Asian Summer Monsoon. Quaternary Science Reviews78: 65–76.
55.
SunQXieMShiL, et al. (2013) Alkanes, compound-specific carbon isotope measures and climate variation during the last millennium from varved sediments of Lake Xiaolongwan, northeast China. Journal of Paleolimnology50(3): 331–344.
56.
ThompsonJCWrightDKIvorySJ, et al. (2021) Early human impacts and ecosystem reorganization in southern-central Africa. Science Advances7(19): eabf9776.
57.
WangSLüHLiuJ, et al. (2007) The early Holocene optimum inferred from a high-resolution pollen record of Huguangyan Maar Lake in southern China. Chinese Science Bulletin52(20): 2829–2836.
58.
WangXChuGShengM, et al. (2016) Millennial-scale Asian summer monsoon variations in South China since the last deglaciation. Earth and Planetary Science Letters451: 22–30.
59.
XieMSunQDongH, et al. (2020) n-alkanes and compound carbon isotope records from Lake Yiheshariwusu in the Hulun Buir sandy land, northeastern China. Holocene30(10): 1451–1461.
60.
XueJLiJDangX, et al. (2017) Paleohydrological changes over the last 4000 years in the middle and lower reaches of the Yangtze River: Evidence from particle size and n-alkanes from Longgan Lake. Holocene27: 1318–1324.
61.
XuJXZhengZHuangKY, et al. (2013) Impacts of human activities on ecosystems during the past 1300 years in Pingnan area of Fujian Province, China. Quaternary International286: 29–35.
62.
YanchevaGNowaczykNRMingramJ, et al. (2007) Influence of the intertropical convergence zone on the East Asian monsoon. Nature445(7123): 74–77.
63.
YangXChenQMaY, et al. (2018) New radiocarbon and archaeobotanical evidence reveal the timing and route of southward dispersal of rice farming in south China. Science Bulletin63(22): 1495–1501.
64.
ZengYChenJZhuZ, et al. (2012) The wet Little Ice Age recorded by sediments in Huguangyan Lake, tropical South China. Quaternary International263: 55–62.
65.
ZhangZZhaoMEglintonG, et al. (2006) Leaf wax lipids as paleovegetational and paleoenvironmental proxies for the Chinese Loess Plateau over the last 170kyr. Quaternary Science Reviews25(5-6): 575–594.
66.
ZhaoWXieS (1988) History of Population in China. Beijing: People’s Publishing House.
67.
ZhengZMaTRobertsP, et al. (2021) Anthropogenic impacts on Late Holocene land-cover change and floristic biodiversity loss in tropical southeastern Asia. Proceedings of the National Academy of Sciences of the United States of America118(40): e2022210118.
68.
ZongYHuangGSwitzerAD, et al. (2009) An evolutionary model for the Holocene formation of the Pearl River delta, China. Holocene19(1): 129–142.
69.
ZongYZhengZHuangK, et al. (2013) Changes in sea level, water salinity and wetland habitat linked to the late agricultural development in the Pearl River delta plain of China. Quaternary Science Reviews70: 145–157.
Supplementary Material
Please find the following supplemental material available below.
For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.
For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.
