Abstract：
The Qinghai-Tibet Plateau (QTP) is characterized by a vast number of frozen and unfrozen freshwater reservoirs, which is why it is also called \"the third pole\" of the Earth or \"Asian Water Tower\". We analyzed testate amoeba (TA) biodiversity and corresponding protozoic biosilicification in lake sediments of the QTP in relation to environmental properties (freshwater conditions, elevation, and climate). As TA are known as excellent bio-indicators, our results allowed us to derive conclusions about the influence of climate warming on TA communities and microbial biogeochemical silicon (Si) cycling. We found a total of 113 TA taxa including some rare and one unknown species in the analyzed lake sediments of the QTP highlighting the potential of this remote region for TA biodiversity. >1/3 of the identified TA taxa were relatively small (<30 μm) reflecting the relatively harsh environmental conditions in the examined lakes. TA communities were strongly affected by physico-chemical properties of the lakes, especially water temperature and pH, but also elevation and climate conditions (temperature, precipitation). Our study reveals climate-related changes in TA biodiversity with consequences for protozoic biosilicification. As the warming trend in the QTP is two to three times faster compared to the global average, our results provide not only deeper insights into the relations between TA biodiversity and environmental properties, but also predictions of future developments in other regions of the world. Moreover, our results provide fundamental data for paleolimnological reconstructions. Thus, examining the QTP is helpful to understand microbial biogeochemical Si cycling in the past, present, and future.
摘要：
青藏高原(QTP)的特点是大量冰冻和不冻的淡水水库,这就是为什么它也被称为地球的“第三极”或“亚洲水塔”。我们分析了QTP湖泊沉积物中与环境特性有关的茶酸盐变形虫（TA）生物多样性和相应的原生生物硅化作用（淡水条件，高程,和气候）。由于TA被称为优秀的生物指标，我们的结果使我们能够得出有关气候变暖对TA群落和微生物生物地球化学硅（Si）循环的影响的结论。我们在QTP的分析湖泊沉积物中总共发现了113个TA分类单元，其中包括一些稀有物种和一种未知物种，突显了该偏远地区对TA生物多样性的潜力。>1/3的确定的TA类群相对较小（<30μm），反映了所检查湖泊中相对恶劣的环境条件。TA群落受到湖泊理化性质的强烈影响，特别是水温和pH值，还有海拔和气候条件(温度，降水)。我们的研究揭示了与气候相关的TA生物多样性变化，并对原生生物硅化产生影响。由于QTP的变暖趋势比全球平均水平快两到三倍，我们的结果不仅为TA生物多样性与环境属性之间的关系提供了更深入的见解，但也预测世界其他地区的未来发展。此外，我们的结果为古生物重建提供了基础数据。因此，检查QTP有助于了解过去微生物生物地球化学硅循环，present,和未来。
