Acidic mining lakes (pH <3) are specific habitats exhibiting particular chemical and biological characteristics. The species richness is low and mixotrophy and omnivory are common features of the plankton food web in such lakes. The plankton community structure of mining lakes of different morphometry and mixing type but similar chemical characteristics (Lake 130, Germany and Lake Langau, Austria) was investigated. The focus was laid on the species composition, the trophic relationship between the phago-mixotrophic flagellate Ochromonas sp. and bacteria and the formation of a deep chlorophyll maximum along a vertical pH-gradient. The shallow wind-exposed Lake 130 exhibited a higher species richness than Lake Langau. This increase in species richness was made up mainly by mero-planktic species, suggesting a strong benthic/littoral - pelagic coupling. Based on the field data from both lakes, a nonlinear, negative relation between bacteria and Ochromonas biomass was found, suggesting that at an Ochromonas biomass below 50 μg C L(-1), the grazing pressure on bacteria is low and with increasing Ochromonas biomass bacteria decline. Furthermore, in Lake Langau, a prominent deep chlorophyll maximum was found with chlorophyll concentrations ca. 50 times higher than in the epilimnion which was build up by the euglenophyte Lepocinclis sp. We conclude that lake morphometry, and specific abiotic characteristics such as mixing behaviour influence the community structure in these mining lakes.

中文翻译：

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湖泊形态学和风暴露可能会塑造酸性采矿湖泊中的浮游生物群落结构

酸性采矿湖（pH <3）是具有特殊化学和生物特征的特定栖息地。物种丰富度低，混养和杂食是此类湖泊浮游生物食物网的共同特征。研究了不同形态和混合类型但化学特征相似的采矿湖泊（德国130湖和奥地利Langau湖）的浮游生物群落结构。重点是物种组成，吞噬混合营养鞭毛虫 Ochromonas sp 之间的营养关系。和细菌以及沿垂直 pH 梯度形成深叶绿素最大值。暴露于浅风的 130 湖的物种丰富度高于朗高湖。物种丰富度的增加主要由浮游物种构成，表明强烈的底栖/沿海 - 远洋耦合。根据两个湖泊的实地数据，发现细菌与 Ochromonas 生物量之间存在非线性负相关关系，这表明在 Ochromonas 生物量低于 50 μg CL(-1) 时，对细菌的放牧压力较低，并且随着 Ochromonas 生物量细菌的增加衰退。此外，在朗高湖中，发现了一个显着的深叶绿素最大值，叶绿素浓度约为。比眼科植物 Lepocinclis sp. 建立的 eliminion 高 50 倍。我们得出结论，湖泊形态学和特定的非生物特征（如混合行为）影响这些采矿湖泊的群落结构。表明在低于 50 μg CL(-1) 的 Ochromonas 生物量下，对细菌的放牧压力较低，并且随着 Ochromonas 生物量的增加，细菌会下降。此外，在朗高湖中，发现了一个显着的深叶绿素最大值，叶绿素浓度约为。比眼科植物 Lepocinclis sp. 建立的 eliminion 高 50 倍。我们得出结论，湖泊形态学和特定的非生物特征（如混合行为）影响这些采矿湖泊的群落结构。表明在低于 50 μg CL(-1) 的 Ochromonas 生物量下，对细菌的放牧压力较低，并且随着 Ochromonas 生物量的增加，细菌会下降。此外，在朗高湖中，发现了一个显着的深叶绿素最大值，叶绿素浓度约为。比眼科植物 Lepocinclis sp. 建立的 eliminion 高 50 倍。我们得出结论，湖泊形态学和特定的非生物特征（如混合行为）影响这些采矿湖泊的群落结构。