Xiuyuan Gu , Andrey N. Tsyganov , Natalia G. Mazei , Kirill V. Babeshko , Victor A. Chernyshov , Elena Yu Novenko , Yuri A. Mazei
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引用次数: 0
Abstract
Carbon storage capacity of peat deposits in permafrost mires is highly sensitive to climate change which effects might be strongly mediated by mire moisture and permafrost. Thus, it is essential to develop appropriate indicator tools of hydrological regime which can be used for monitoring present and past conditions in these mires. We use testate amoebae to investigate their indicator value to water table depth (WTD) and substrate water content (SWC) and to develop transfer functions for quantitative reconstructions of these environmental characteristics in the permafrost mires on the Central Siberian Plateau. In many cased, direct measurement of WTD in permafrost mires are not possible due to the presence of ice, so that SWC can be used as an alternative characteristic. Overall, 330 surface samples were collected in five study regions together with the corresponding environmental measurements. We find that testate amoebae form diverse assemblages with the species structure strongly controlled by WTD and SWC. We developed two testate amoeba-based transfer functions to reconstruct these characteristics based on Modern Analogue Technique which were assessed using leave-one-out and bootstrap cross-validation. We find that both transfer functions have good predictive power (for WTD: RMSEP = 6.8–7.6 cm, R2 = 0.54, for SWC: RMSEP = 2.0–2.3 %, R2 = 0.74–0.76). The ecological preferences of the majority of testate amoebae were similar to those reported by the studies in lower-latitudes, although some hydrophilic taxa were observed in the drier end of the surface wetness gradient. These data represent an important source for improvement of quantitative reconstructions based on subfossil testate amoebae in permafrost mires.
期刊介绍:
Quaternary Science Reviews caters for all aspects of Quaternary science, and includes, for example, geology, geomorphology, geography, archaeology, soil science, palaeobotany, palaeontology, palaeoclimatology and the full range of applicable dating methods. The dividing line between what constitutes the review paper and one which contains new original data is not easy to establish, so QSR also publishes papers with new data especially if these perform a review function. All the Quaternary sciences are changing rapidly and subject to re-evaluation as the pace of discovery quickens; thus the diverse but comprehensive role of Quaternary Science Reviews keeps readers abreast of the wider issues relating to new developments in the field.