Abstract
Historical biome changes on the Tibetan Plateau provide important information that improves our understanding of the alpine vegetation responses to climate changes. However, a comprehensively quantitative reconstruction of the historical Tibetan Plateau biomes is not possible due to the lack of quantitative methods that enable appropriate classification of alpine biomes based on proxy data such as fossil pollen records. In this study, a pollen-based biome classification model was developed by applying a random forest algorithm (a supervised machine learning method) based on modern pollen assemblages on and around the Tibetan Plateau, and its robustness was assessed by comparing its results with the predictions of the biomisation method. The results indicated that modern biome distributions reconstructed using the random forest model based on modern pollen data generally concurred with the observed zonal vegetation. The random forest model had a significantly higher accuracy than the biomisation method, indicating the former is a more suitable tool for reconstructing alpine biome changes on the Tibetan Plateau. The random forest model was then applied to reconstruct the Tibetan Plateau biome changes from 22 ka BP to the present based on 51 fossil pollen records. The reconstructed biome distribution changes on the Tibetan Plateau generally corresponded to global climate changes and Asian monsoon variations. In the Last Glacial Maximum, the Tibetan Plateau was mainly desert with subtropical forests distributed in the southeast. During the last deglaciation, the alpine steppe began expanding and gradually became zonal vegetation in the central and eastern regions. Alpine meadow occupied the eastern and southeastern areas of the Tibetan Plateau since the early Holocene, and the forest-meadow-steppe-desert pattern running southeast to northwest on the Tibetan Plateau was established afterwards. In the mid-Holocene, subtropical forests extended north, which reflected the “optimum” condition. During the late Holocene, alpine meadows and alpine steppes expanded south.
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References
Alley R B, Mayewski P A, Sowers T, Stuiver M, Taylor K C, Clark P U. 1997. Holocene climatic instability: A prominent, widespread event 8200 yr ago. Geology, 25: 483–486
An Z S, Kutzbach J E, Prell W L, Porter S C. 2001. Evolution of Asian monsoons and phased uplift of the Himalaya-Tibetan plateau since Late Miocene times. Nature, 411: 62–66
An Z S, Wu G X, Li J P, Sun Y B, Liu Y, Zhou W J, Cai Y J, Duan A M, Li L, Mao J Y, Cheng H, Shi Z G, Tan L C, Yan H, Ao H, Chang H, Feng J. 2015. Global monsoon dynamics and climate change. Annu Rev Earth Planet Sci, 43: 29–77
Blaauw M, Christen J A. 2011. Flexible paleoclimate age-depth models using an autoregressive gamma process. Bayesian Anal, 6: 457–474
Blaauw M, Christen J A. 2019. rbacon: Age-Depth Modelling using Bayesian Statistics
Bond G, Showers W, Cheseby M, Lotti R, Almasi P, Demenocal P, Priore P, Cullen H, Hajdas I, Bonani G. 1997. A pervasive millennial-scale cycle in North Atlantic Holocene and Glacial climates. Science, 278: 1257–1266
Breiman L, Friedman J H, Olshen R A, Stone C J. 1984. Classification and Regression Trees. Monterey: Wadsworth and Brooks/Cole
Breiman L. 2001. Random Forests. Mach Learn, 45: 5–32
Bunting M J, Middleton R. 2009. Equifinality and uncertainty in the interpretation of pollen data: The Multiple Scenario Approach to reconstruction of past vegetation mosaics. Holocene, 19: 799–803
Cao X Y, Herzschuh U, Telford R J, Ni J. 2014. A modern pollen-climate dataset from China and Mongolia: Assessing its potential for climate reconstruction. Rev Palaeobot Palynol, 211: 87–96
Cao X Y, Ni J, Herzschuh U, Wang Y B, Zhao Y. 2013. A late Quaternary pollen dataset from eastern continental Asia for vegetation and climate reconstructions: Set up and evaluation. Rev Palaeobot Palynol, 194: 21–37
Chen F H, Chen J H, Huang W, Chen S Q, Huang X Z, Jin L Y, Jia J, Zhang X J, An C B, Zhang J W, Zhao Y, Yu Z C, Zhang R H, Liu J B, Zhou A F, Feng S. 2019. Westerlies Asia and monsoonal Asia: Spatiotemporal differences in climate change and possible mechanisms on decadal to sub-orbital timescales. Earth-Sci Rev, 192: 337–354
Chen F H, Zhang J F, Liu J B, Cao X Y, Hou J Z, Zhu L P, Xu X K, Liu X J, Wang M D, Wu D, Huang L X, Zeng T, Zhang S, Huang W, Zhang X, Yang K. 2020. Climate change, vegetation history, and landscape responses on the Tibetan Plateau during the Holocene: A comprehensive review. Quat Sci Rev, 243: 106444
Chen Y, Ni J, Herzschuh U. 2010. Quantifying modern biomes based on surface pollen data in China. Glob Planet Change, 74: 114–131
Clark P U, Shakun J D, Baker P A, Bartlein P J, Brewer S, Brook E, Carlson A E, Cheng H, Kaufman D S, Liu Z, Marchitto T M, Mix A C, Morrill C, Otto-Bliesner B L, Pahnke K, Russell J M, Whitlock C, Adkins J F, Blois J L, Clark J, Colman S M, Curry W B, Flower B P, He F, Johnson T C, Lynch-Stieglitz J, Markgraf V, McManus J, Mitrovica J X, Moreno P I, Williams J W. 2012. Global climate evolution during the last deglaciation. Proc Natl Acad Sci USA, 109: E1134–E1142
Cour P, Zheng Z, Duzer D, Calleja M, Yao Z. 1999. Vegetational and climatic significance of modern pollen rain in northwestern Tibet. Rev Palaeobot Palynol, 104: 183–204
Cutler D R, Edwards Jr T C, Beard K H, Cutler A, Hess K T, Gibson J, Lawler J J. 2007. Random forests for classification in ecology. Ecology, 88: 2783–2792
Dallmeyer A, Claussen M, Herzschuh U, Fischer N. 2011. Holocene vegetation and biomass changes on the Tibetan Plateau—A model-pollen data comparison. Clim Past, 7: 881–901
Dykoski C A, Edwards R L, Cheng H, Yuan D X, Cai Y J, Zhang M L, Lin Y S, Qing J M, An Z S, Revenaugh J. 2005. A high-resolution, absolute-dated Holocene and deglacial Asian monsoon record from Dongge Cave, China. Earth Planet Sci Lett, 233: 71–86
Fall P L. 1992. Pollen accumulation in a montane region of Colorado, USA: A comparison of moss polsters, atmospheric traps, and natural basins. Rev Palaeobot Palynol, 72: 169–197
Felde V A, Peglar S M, Bjune A E, Grytnes J A, Birks H J B. 2014. The relationship between vegetation composition, vegetation zones and modern pollen assemblages in Setesdal, southern Norway. Holocene, 24: 985–1001
Guiot J, Goeury C. 1996. PPPBase, a software for statistical analysis of paleoecological and paleoclimatological data. Dendrochronol, 14: 295–300
Herzschuh U, Borkowski J, Schewe J, Mischke S, Tian F. 2014. Moisture-advection feedback supports strong early-to-mid Holocene monsoon climate on the eastern Tibetan Plateau as inferred from a pollen-based reconstruction. Palaeogeogr Palaeoclimatol Palaeoecol, 402: 44–54
Herzschuh U, Kramer A, Mischke S, Zhang C J. 2009. Quantitative climate and vegetation trends since the late glacial on the northeastern Tibetan Plateau deduced from Koucha Lake pollen spectra. Quat Res, 71: 162–171
Herzschuh U, Winter K, Wunnemann B, Li S J. 2006. A general cooling trend on the central Tibetan Plateau throughout the Holocene recorded by the Lake Zigetang pollen spectra. Quat Int, 154–155: 113–121
Li K, Liao M N, Ni J, Liu X Q, Wang Y B. 2019. Treeline composition and biodiversity change on the southeastern Tibetan Plateau during the past millennium, inferred from a high-resolution alpine pollen record. Quat Sci Rev, 206: 44–55
Liaw A, Wiener M. 2002. Classification and regression by randomForest. R News, 2: 18–22
Lisitsyna O V, Hicks S, Huusko A. 2012. Do moss samples, pollen traps and modern lake sediments all collect pollen in the same way? A comparison from the forest limit area of northernmost Europe. Veget Hist Archaeobot, 21: 187–199
Marchant R, Cleef A, Harrison S P, Hooghiemstra H, Markgraf V, van Boxel J, Ager T, Almeida L, Anderson R, Baied C, Behling H, Berrio J C, Burbridge R, Björck S, Byrne R, Bush M, Duivenvoorden J, Flenley J, De Oliveira P, van Geel B, Graf K, Gosling W D, Harbele S, van der Hammen T, Hansen B, Horn S, Kuhry P, Ledru M P, Mayle F, Leyden B, Lozano-García S, Melief A M, Moreno P, Moar N T, Prieto A, van Reenen G, Salgado-Labouriau M, Schäbitz F, Schreve-Brinkman E J, Wille M. 2009. Pollen-based biome reconstructions for Latin America at 0, 6000 and 18000 radiocarbon years ago. Clim Past, 5: 725–767
Marcott S A, Shakun J D, Clark P U, Mix A C. 2013. A reconstruction of regional and global temperature for the past 11,300 years. Science, 339: 1198–1201
Molnar P, Boos W R, Battisti D S. 2010. Orographic controls on climate and paleoclimate of Asia: Thermal and mechanical roles for the Tibetan Plateau. Annu Rev Earth Planet Sci, 38: 77–102
Ni J, Cao X Y, Jeltsch F, Herzschuh U. 2014. Biome distribution over the last 22,000 yr in China. Palaeogeogr Palaeoclimatol Palaeoecol, 409: 33–47
Ni J, Yu G, Harrison S P, Prentice I C. 2010. Palaeovegetation in China during the late Quaternary: Biome reconstructions based on a global scheme of plant functional types. Palaeogeogr Palaeoclimatol Palaeoecol, 289: 44–61
Pickett E J, Harrison S P, Hope G, Harle K, Dodson J R, Peter Kershaw A, Colin Prentice I, Backhouse J, Colhoun E A, D’Costa D, Flenley J, Grindrod J, Haberle S, Hassell C, Kenyon C, Macphail M, Martin H, Martin A H, McKenzie M, Newsome J C, Penny D, Powell J, Ian Raine J, Southern W, Stevenson J, Sutra J P, Thomas I, Kaars S, Ward J. 2004. Pollen-based reconstructions of biome distributions for Australia, Southeast Asia and the Pacific (SEAPAC region) at 0, 6000 and 18,000 14C yr BP. J Biogeogr, 31: 1381–1444
Prentice C, Guiot J, Huntley B, Jolly D, Cheddadi R. 1996. Reconstructing biomes from palaeoecological data: A general method and its application to European pollen data at 0 and 6 ka. Clim Dyn, 12: 185–194
Prentice I C, Jolly D. 2000. Mid-Holocene and glacial-maximum vegetation geography of the northern continents and Africa. J Biogeogr, 27: 507–519
Prentice I C, Webb III T. 1998. BIOME 6000: Reconstructing global mid-Holocene vegetation patterns from palaeoecological records. J Biogeogr, 25: 997–1005
Qin F. 2021. Modern pollen assemblages of the surface lake sediments from the steppe and desert zones of the Tibetan Plateau. Sci China Earth Sci, 64: 425–439
R Core Team. 2018. R: A language and environment for statistical computing. Vienna, Austria: R Foundation for Statistical Computing
Shakun J D, Carlson A E. 2010. A global perspective on Last Glacial Maximum to Holocene climate change. Quat Sci Rev, 29: 1801–1816
Shen C M, Liu K B, Tang L Y, Overpeck J T. 2006. Quantitative relationships between modern pollen rain and climate in the Tibetan Plateau. Rev Palaeobot Palynol, 140: 61–77
Shi F, Lu H Y, Guo Z T, Yin Q Z, Wu H B, Xu C X, Zhang E L, Shi J F, Cheng J, Xiao X Y, Zhao C. 2021. The position of the Current Warm Period in the context of the past 22,000 years of summer climate in China. Geophys Res Lett, 48: e91940
Shi W, Jiang H C, Mao X, Xu H Y. 2020. Pollen record of climate change during the last deglaciation from the eastern Tibetan Plateau. PLoS ONE, 15: e0232803
Sobol M K, Finkelstein S A. 2018. Predictive pollen-based biome modeling using machine learning. PLoS ONE, 13: e0202214
Sobol M K, Scott L, Finkelstein S A. 2019. Reconstructing past biomes states using machine learning and modern pollen assemblages: A case study from Southern Africa. Quat Sci Rev, 212: 1–17
Song M H, Zhou C P, Ouyang H. 2005. Simulated distribution of vegetation types in response to climate change on the Tibetan Plateau. J Vegetation Sci, 16: 341–350
Sugita S. 2007a. Theory of quantitative reconstruction of vegetation I: Pollen from large sites REVEALS regional vegetation composition. Holocene, 17: 229–241
Sugita S. 2007b. Theory of quantitative reconstruction of vegetation II: All you need is LOVE. Holocene, 17: 243–257
Sun A Z, Luo Y L, Wu H B, Chen X D, Guo Z T. 2020. An updated biomization scheme and vegetation reconstruction based on a synthesis of modern and mid-Holocene pollen data in China. Glob Planet Change, 192: 103178
Tang L Y, Li C H. 2001. Temporal-spatial distribution of the Holocene vegetation in the Tibetan Plateau (in Chinese). J Glaciol Geocryol, 23: 367–374
Tang L, Shen C, Lu H, Li C, Ma Q. 2021. Fifty years of Quaternary palynology in the Tibetan Plateau. Sci China Earth Sci, 64: 1825–1843
Tian F, Cao X Y, Dallmeyer A, Lohmann G, Zhang X, Ni J, Andreev A, Anderson P M, Lozhkin A V, Bezrukova E, Rudaya N, Xu Q H, Herzschuh U. 2018. Biome changes and their inferred climatic drivers in northern and eastern continental Asia at selected times since 40 cal ka bp. Veget Hist Archaeobot, 27: 365–379
Wilmshurt J M, McGlone M S. 2005. Origin of pollen and spores in surface lake sediments: Comparison of modern palynomorph assemblages in moss cushions, surface soils and surface lake sediments. Rev Palaeobot Palynol, 136: 1–15
Wu Z Y. 1980. Vegetation of China. Beijing: Science Press
Yu G, Chen X, Ni J, Cheddadi R, Guiot J, Han H, Harrison S P, Huang C, Ke M, Kong Z C, Li S, Li W Y, Liew P, Liu G, Liu J, Liu Q, Liu K B, Prentice I C, Qui W, Ren G, Song C, Sugita S, Sun X J, Tang L Y, van C E, Xia Y, Xu Q H, Yan S, Yang X, Zhao J, Zheng Z. 2000. Palaeovegetation of China: A pollen data-based synthesis for the mid-Holocene and last glacial maximum. J Biogeogr, 27: 635–664
Zhang X S. 1978. The plateau zonality of vegetation in Xizang (in Chinese). Acta Botanica Sin, 20: 140–149
Zhang X S. 2007. Vegetation Map of China and Its Geographic Pattern-Illustration of the Vegetation Map of The People’s Republic of China (1:1000000) (in Chinese). Beijing: Geology Press
Zhang Y L, Li B Y, Zheng D. 2014. Datasets of the boundary and area of the Tibetan Plateau (in Chinese). Acta Geogr Sin, 69: 65–68
Zhang Z P, Liu J B, Chen J, Chen S Q, Shen Z W, Chen J, Liu X K, Wu D, Sheng Y W, Chen F H. 2021. Holocene climatic optimum in the East Asian monsoon region of China defined by climatic stability. Earth-Sci Rev, 212: 103450
Zhao Y, Liang C, Cui Q Y, Qin F, Zheng Z, Xiao X Y, Ma C M, Felde V A, Liu Y L, Li Q, Zhang Z Y, Herzschuh U, Xu Q H, Wei H C, Cai M T, Cao X Y, Guo Z T, Birks H J B. 2021. Temperature reconstructions for the last 1.74-Ma on the eastern Tibetan Plateau based on a novel pollen-based quantitative method. Glob Planet Change, 199: 103433
Zhao Y, Tzedakis P C, Li Q, Qin F, Cui Q, Liang C, Birks H J B, Liu Y L, Zhang Z Z, Ge J Y, Zhao H, Felde V A, Deng C L, Cai M T, Li H, Ren W H, Wei H C, Yang H F, Zhang J W, Yu Z C, Guo Z T. 2020. Evolution of vegetation and climate variability on the Tibetan Plateau over the past 1.74 million years. Sci Adv, 6: eaay6193
Zhao Y, Xu Q H, Huang X Z, Guo X L, Tao S C. 2009. Differences of modern pollen assemblages from lake sediments and surface soils in arid and semi-arid China and their significance for pollen-based quantitative climate reconstruction. Rev Palaeobot Palynol, 156: 519–524
Zhao Y, Yu Z C, Zhao W W. 2011. Holocene vegetation and climate histories in the eastern Tibetan Plateau: Controls by insolation-driven temperature or monsoon-derived precipitation changes? Quat Sci Rev, 30: 1173–1184
Zheng D, Zhang R Z, Yang Q. 1979. On the natural zonation in the Qinghai-Xizang Plateau. Acta Geogr Sin, 34: 1–11
Zheng Z, Wei J H, Huang K Y, Xu Q H, Lü H Y, Tarasov P, Luo C X, Beaudouin C, Deng Y, Pan A D, Zheng Y W, Luo Y L, Nakagawa T, Li C H, Yang S X, Peng H H, Cheddadi R. 2014. East Asian pollen database: Modern pollen distribution and its quantitative relationship with vegetation and climate. J Biogeogr, 41: 1819–1832
Acknowledgements
The authors wish to thank Prof. Zhuo ZHENG (Sun Yat-sen University, Guangzhou, China) and Prof. Xiayun XIAO (Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing, China) for sharing modern pollen data, Dr Chen LIANG (Heibei GEO University, Shijiazhuang, China) for her assistance with data analysis, and Dr Zhiyong ZHANG (Lushan Botanical Garden, Chinese Academy of Sciences, Jiujiang, China) for the helpful discussions on biomisation method. This research was supported by the National Natural Science Foundation of China (Grant No. 41690113), the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA20070101), the National Natural Science Foundation of China (Grant Nos. 42071114, 41977395, and 41671202).
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Appendix C Table showing comparisons between the observed biome types of modern pollen samples and the predictions from the random forest model and biomisation method
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Qin, F., Zhao, Y. & Cao, X. Biome reconstruction on the Tibetan Plateau since the Last Glacial Maximum using a machine learning method. Sci. China Earth Sci. 65, 518–535 (2022). https://doi.org/10.1007/s11430-021-9867-1
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DOI: https://doi.org/10.1007/s11430-021-9867-1