Accurate lake sediment-derived palaeoenvironmental reconstructions require in-depth knowledge on sediment record formation processes. In order to understand formation of laminated sediments in the eutrophic Lake Kierskie (western Poland) we conducted a year-round (November 2015–October 2016), monthly sediment trap study along with physico-chemical water properties, water transparency, hardness, alkalinity, nutrients and solute content, trophic state indices, and the phytoplankton assemblage monitoring. Sedimentation in Lake Kierskie primarily resulted from the activity of photosynthetic organisms. The maxima of biogenic silica accumulation were synchronous with the bloom of centric diatoms observed in March and April. These were followed by the most intensive precipitation of CaCO 3 noted between mid-April and mid-June, that corroborated with the domination of Stephanodiscus hantzschii and small flagellate forms acting as nucleation sites for crystal formation. At the same time shift from the diatom-dominated assemblages to the communities composed of chlorophytes, cryptophytes, and dinoflagellates, the groups with cellulose external covering, resulted in decreased proportion between SiO 2 and organic matter. CaCO 3 precipitation continued in the summer months, however its amount decreased simultaneously with a drop in S. hantzschii biomass. The significant overall flux of biogenically mediated materials from epilimnion was promoted by eutrophic towards hypertrophic conditions in Lake Kierskie revealed by the trophic state indices. Mixing of the water column in autumn triggered resuspension and redeposition of the previously deposited sediments resulting in the second, after the early spring, maximum sediment flux. Minima of sediment accumulation were observed during the winter water stratification when the smallest particles sedimented from suspension. The sediment flux to the lake bottom recorded by us in a 1-year, monthly sediment trap study matches a sequence of pale, whitish lamina deposited during spring and summer, followed by dark, grayish or black lamina deposited in the autumn and winter, observed in the macroscopic investigation of the short (0.5 m) core from Lake Kierskie. Preservation of distinct laminations in the dimictic Lake Kierskie is supported by anoxic hypolimnion developed under the high supply of organic matter from epilimnion of this highly eutrophic lake.

中文翻译：

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最近在波兰西部高富营养化的 Kierskie 湖中沉积层状沉积物：湖沼学监测和沉积物圈闭的 1 年试点研究

准确的湖泊沉积物衍生的古环境重建需要对沉积物记录形成过程的深入了解。为了了解富营养化的 Kierskie 湖（波兰西部）中层状沉积物的形成，我们进行了全年（2015 年 11 月至 2016 年 10 月）、每月沉积物圈闭研究以及物理化学水特性、水透明度、硬度、碱度、营养物质和溶质含量、营养状态指数和浮游植物组合监测。Kierskie 湖的沉积主要是由光合生物的活动引起的。生物二氧化硅积累的最大值与 3 月和 4 月观察到的中心硅藻的大量繁殖同步。随后是在 4 月中旬和 6 月中旬之间注意到的最强烈的 CaCO 3 降水，这证实了 Stephanodiscus hantzschii 和作为晶体形成成核位点的小鞭毛虫形式的支配地位。同时，从以硅藻为主的群落向以叶绿藻、隐藻和鞭毛藻为主的群落转变，这些具有纤维素外覆的群落导致SiO 2 与有机质的比例下降。CaCO 3 降水在夏季持续，但其数量随着 S. hantzschii 生物量的下降而减少。营养状态指数显示，基尔斯基湖的富营养化条件促进了生物源性介导材料的显着总体通量。秋季水体的混合引发了先前沉积的沉积物的再悬浮和再沉积，导致第二个，即早春之后的最大沉积物通量。当最小的颗粒从悬浮液中沉淀出来时，在冬季水分层过程中观察到沉积物积累的最小值。我们在为期 1 年的每月沉积物圈闭研究中记录的湖底沉积物通量与春季和夏季沉积的一系列苍白、发白的层相匹配，观察到的则是秋季和冬季沉积的深色、灰色或黑色层在对 Kierskie 湖短 (0.5 m) 岩心的宏观研究中。