| DOI: | 10.1016/j.quascirev.2015.10.031
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| Scopus记录号: | 2-s2.0-84952044472
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| 论文题名: | Limits to lichenometry |
| 作者: | Rosenwinkel S.; Korup O.; Landgraf A.; Dzhumabaeva A.
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| 刊名: | Quaternary Science Reviews
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| ISSN: | 2773791
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| 出版年: | 2015
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| 卷: | 129 | | 起始页码: | 229
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| 结束页码: | 238
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| 语种: | 英语
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| 英文关键词: | Absolute age dating
; Kyrgyzstan
; Lichenometry
; Rock glacier
; Tien Shan
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| Scopus关键词: | Calibration
; Fungi
; Uncertainty analysis
; Absolute ages
; Kyrgyzstan
; Lichenometry
; Rock glaciers
; Tien Shan
; Rocks
; biochronology
; calibration
; colonization
; geochronology
; growth modeling
; Holocene
; lichen
; lichenometry
; paleoclimate
; regression analysis
; rock glacier
; Kyrgyzstan
; Tien Shan
; Aspicilia
; Rhizocarpon geographicum
; Xanthoria elegans
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| 英文摘要: | Lichenometry is a straightforward and inexpensive method for dating Holocene rock surfaces. The rationale is that the diameter of the largest lichen scales with the age of the originally fresh rock surface that it colonised. The success of the method depends on finding the largest lichen diameters, a suitable lichen-growth model, and a robust calibration curve. Recent critique of the method motivates us to revisit the accuracy and uncertainties of lichenometry. Specifically, we test how well lichenometry is capable of resolving the ages of different lobes of large active rock glaciers in the Kyrgyz Tien Shan. We use a bootstrapped quantile regression to calibrate local growth curves of Xanthoria elegans, Aspicilia tianshanica, and Rhizocarpon geographicum, and report a nonlinear decrease in dating accuracy with increasing lichen diameter. A Bayesian type of an analysis of variance demonstrates that our calibration allows discriminating credibly between rock-glacier lobes of different ages despite the uncertainties tied to sample size and correctly identifying the largest lichen thalli. Our results also show that calibration error grows with lichen size, so that the separability of rock-glacier lobes of different ages decreases, while the tendency to assign coeval ages increases. The abundant young (<200 yr) specimen of fast-growing X. elegans are in contrast with the fewer, slow-growing, but older (200-1500 yr) R. geographicum and A. tianshanica, and record either a regional reactivation of lobes in the past 200 years, or simply a censoring effect of lichen mortality during early phases of colonisation. The high variance of lichen sizes captures the activity of rock-glacier lobes, which is difficult to explain by regional climatic cooling or earthquake triggers alone. Therefore, we caution against inferring palaeoclimatic conditions from the topographic position of rock-glacier lobes. We conclude that lichenometry works better as a tool for establishing a relative, rather than an absolute, chronology of rock-glacier lobes in the northern Tien Shan. © 2015 Elsevier Ltd. |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/59773
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| Appears in Collections: | 过去全球变化的重建
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作者单位: | Institute of Earth and Environmental Sciences, University of Potsdam, Potsdam, Germany; Kyrgyz Institute of Seismology, Bishkek, Kyrgyzstan
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| Recommended Citation: | |
Rosenwinkel S.,Korup O.,Landgraf A.,et al. Limits to lichenometry[J]. Quaternary Science Reviews,2015-01-01,129
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