Kong Tianshu, Reid R Pamela, Suosaari Erica P, Maizel Daniela, Daza Luis R, Palma Alvaro T, Oehlert Amanda M
Department of Marine Geosciences, Rosenstiel School of Marine, Atmospheric, and Earth Science, University of Miami, Miami, Florida, United States of America.
Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution, Washington, Columbia, United States of America.
PLoS One. 2025 May 5;20(5):e0321759. doi: 10.1371/journal.pone.0321759. eCollection 2025.
Saline lakes exist in various morphologies within salar environments, occurring as ephemeral to persistent bodies of water despite evaporative conditions. Salar environments are often characterized by strong diurnal fluctuations in temperature, UV irradiation, and wind speed, however, the extent to which these meteorological conditions impact saline lakes with different morphological characteristics has yet to be investigated. Here, we evaluate the impacts of diurnal changes in wind speed and wind direction on lake water temperature, electrical conductivity, alkalinity, and stable isotope ratios of hydrogen (δ2H), oxygen (δ18O), and sulfur (δ34SSO4) in two Na-Cl saline lakes in the Salar de Llamara (Atacama Desert, Northern Chile) with different morphologies. Results indicate that water masses in the relatively deeper (~ 0.6 m) steep-sided lake with crystalline lake bottom remained stratified despite the nearly order of magnitude increase in diurnal wind speed, while waters in the relatively shallow (< 0.2 m), gently-sloping lake colonized by microbial mats were well-mixed. Conditions in the shallow, gently-sloping lake were heterogeneous, with diurnal variations approximating 15.6% and 23.9% of known seasonal ranges in temperature and electrical conductivity, respectively. Consequently, the chemistry of shallow, gently-sloping saline lake environments is dynamic on diurnal time scales, indicating that resident microbial communities tolerate a greater range in environmental conditions than previously appreciated. Results suggest that the impacts of diurnal changes in meteorological conditions on saline lake stratification depend on lake morphology, an observation with implications for patterns of mineral deposition in salar environments.
盐沼环境中存在着各种形态的盐湖，尽管存在蒸发条件，但它们以临时性到永久性水体的形式出现。盐沼环境的特点通常是温度、紫外线辐射和风速有强烈的昼夜波动，然而，这些气象条件对具有不同形态特征的盐湖的影响程度尚未得到研究。在这里，我们评估了风速和风向的昼夜变化对智利北部阿塔卡马沙漠盐沼德利亚马拉两个不同形态的氯化钠盐湖的湖水温度、电导率、碱度以及氢（δ2H）、氧（δ18O）和硫（δ34SSO4）稳定同位素比值的影响。结果表明，尽管昼夜风速增加了近一个数量级，但底部为结晶的相对较深（约0.6米）、湖岸陡峭的湖泊中的水体仍保持分层，而被微生物垫覆盖的相对较浅（<0.2米）、湖岸平缓的湖泊中的水体则充分混合。浅的、湖岸平缓的湖泊中的条件是不均匀的，温度和电导率的昼夜变化分别约为已知季节范围的15.6%和23.9%。因此，浅的、湖岸平缓的盐湖环境的化学性质在昼夜时间尺度上是动态的，这表明当地的微生物群落能够耐受比以前认识到的更大范围的环境条件。结果表明，气象条件的昼夜变化对盐湖分层的影响取决于湖泊形态，这一观察结果对盐沼环境中矿物沉积模式具有启示意义。
