Despite a relatively large number of paleoenvironmental and archaeological studies in the Southern Urals, Russia, Holocene moisture dynamics in the region remain a subject of debate. Electrical conductivity (EC) of lake waters in the Southern Urals is climate-dependent and associated with effective moisture. I developed a transfer function using a 72-lake regional diatom dataset and inferred past EC using diatoms in sediment cores from three lakes. The diatom-inferred EC inferences were compared with pollen records to validate the climate interpretation and explore the possible influence of vegetation on lake hydrochemistry. Multivariate analysis showed a clear response of diatom communities to electrical conductivity across a range from 55 to 3780 μS cm −1 . The best electrical conductivity inference model (r 2 boot = 0.78, RMSEP boot = 0.21 log 10 μS cm −1 ), suitable for quantitative reconstructions, was developed using weighted averaging with classical deshrinking. Application of the transfer function to sediment cores from mountain lakes in the forest and forest-steppe regions of the Southern Urals revealed relations between EC and variations in pollen contents of herbs, pine (for the forest-steppe lake) and spruce (for the forest lakes). Although a decrease in EC may be attributable to coniferous forest spread in the watersheds, it is more likely that climate fluctuations caused the coincident shifts in vegetation and lake-water hydrochemistry. Forest lakes were marked by a declining trend in EC since the beginning of the Holocene (11.9–11.5 cal ka BP), which was independent of the larch and birch forest distribution (11.5–10.0 cal ka BP) and was interrupted by minor climate-driven EC increases. Electrical conductivity of lake water was higher than present in the period between 6.5 and 3.8 cal ka BP in all three study lakes. Forest lakes were characterized by gradual increases and decreases in EC, with maximum values occurring ca. 5.0–4.0 cal ka BP. Diatoms in the core from the forest-steppe lake record variations in EC through time. In particular, the record shows highest EC values at 5.3 cal ka BP, a decline in EC at 4.1–3.8 cal ka BP, a slight increase about 3.6 cal ka BP and a substantial decrease since 2.8 cal ka BP.

中文翻译：

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使用俄罗斯乌拉尔湖泊中的硅藻开发和应用电导率传递函数

尽管在俄罗斯乌拉尔南部进行了相对大量的古环境和考古研究，但该地区全新世的水分动态仍然是一个有争议的话题。南乌拉尔湖水的电导率 (EC) 与气候有关，并与有效水分有关。我使用 72 个湖泊的区域硅藻数据集开发了一个传递函数，并使用来自三个湖泊的沉积岩芯中的硅藻推断过去的 EC。将硅藻推断的 EC 推论与花粉记录进行比较，以验证气候解释并探索植被对湖泊水化学的可能影响。多变量分析表明，硅藻群落对 55 至 3780 μS cm -1 范围内的电导率有明确的响应。最佳电导率推断模型（r 2 boot = 0.78，RMSEP boot = 0。21 log 10 μS cm -1 )，适用于定量重建，是使用加权平均和经典去收缩开发的。将传递函数应用于乌拉尔南部森林和森林草原地区山地湖泊沉积物核心揭示了 EC 与草本植物、松树（森林草原湖泊）和云杉（森林）花粉含量变化之间的关系湖泊）。尽管 EC 的减少可能归因于流域中针叶林的蔓延，但更有可能是气候波动导致植被和湖水水化学的同时发生变化。自全新世开始（11.9-11.5 cal ka BP）以来，森林湖泊的特征是 EC 呈下降趋势，这与落叶松和白桦林的分布无关（11.5-10. 0 cal ka BP) 并被气候驱动的 EC 轻微增加中断。在所有三个研究湖泊中，湖水的电导率高于 6.5 至 3.8 cal ka BP 之间的时间。森林湖泊的特征是 EC 的逐渐增加和减少，最大值出现在大约 5.0–4.0 cal ka BP。森林-草原湖核心中的硅藻记录了 EC 随时间的变化。特别是，记录显示 EC 值在 5.3 cal ka BP 时最高，EC 在 4.1–3.8 cal ka BP 时下降，约 3.6 cal ka BP 略有增加，自 2.8 cal ka BP 后显着下降。最大值出现约。5.0–4.0 cal ka BP。森林-草原湖核心中的硅藻记录了 EC 随时间的变化。特别是，记录显示 EC 值在 5.3 cal ka BP 时最高，EC 在 4.1–3.8 cal ka BP 时下降，约 3.6 cal ka BP 略有增加，自 2.8 cal ka BP 后显着下降。最大值出现约。5.0–4.0 cal ka BP。森林-草原湖核心中的硅藻记录了 EC 随时间的变化。特别是，记录显示 EC 值在 5.3 cal ka BP 时最高，EC 在 4.1–3.8 cal ka BP 时下降，约 3.6 cal ka BP 略有增加，自 2.8 cal ka BP 后显着下降。