Tropical high-altitude lakes are vital freshwater ecosystems for the functioning and dynamics of tropical high-altitude wetlands called páramos, found at over 3300 m above sea level. They play a major role in the hydrogeological cycle and provide important hydrological services such as water storage, and yet they are understudied. Describing the patterns and processes of community composition in these lakes is required to better understand the consequences of their degradation by human activities. In this study we tested the geographical and environmental components of distance–decay relationships in the phytoplankton structure across 24 tropical high-altitude lakes from Southern Ecuador. Phytoplankton composition at the phyla level showed high among-lake variation in the tropical high-altitude lakes from Tres Lagunas. We found no links, however, between the geographic distance and phytoplankton composition. On the contrary, we observed some environmentally related patterns of community structure like redox potential, altitude, water temperature, and total phosphorus. The absence of support for the distance–decay relationship observed here can result from a conjunction of local niche-based effects and dispersal limitations. Phytoplankton community composition in the Tres Lagunas system or any other ecosystem may be jointly regulated by niche-based and neutral forces that still need to be explored. Despite not proving a mechanistic explanation for the observed patterns of community structure, we hope our findings provide understanding of these vulnerable and vital ecosystems. More studies in tropical high-altitude lakes are urgently required.

中文翻译：

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在高海拔热带湖泊中度环境距离下浮游植物群落之间的最高组成差异

对于海拔3300 m以上的称为páramos的热带高海拔湿地，热带高海拔湖泊是至关重要的淡水生态系统，用于其功能和动态。它们在水文地质循环中起着重要作用，并提供重要的水文服务，例如储水，但尚未得到充分研究。需要描述这些湖泊中社区组成的模式和过程，以更好地了解人类活动对其造成的破坏的后果。在这项研究中，我们测试了厄瓜多尔南部24个热带高海拔湖泊中浮游植物结构中距离-衰减关系的地理和环境成分。在特雷斯·拉古纳斯（Tres Lagunas）的热带高空湖泊中，浮游植物的种群数量在湖泊内显示出较高的湖间变化。我们没有找到任何链接，但是，在地理距离和浮游植物组成之间。相反，我们观察到了一些与环境相关的群落结构模式，如氧化还原电势，海拔高度，水温和总磷。此处观察到的距离-衰减关系的缺乏支持可能是由于基于局部利基效应和分散限制的共同作用。Tres Lagunas系统或任何其他生态系统中的浮游植物群落组成可能受到基于利基和中立力量的共同调控，仍然需要探索。尽管没有为观察到的社区结构模式提供机械的解释，但我们希望我们的发现能对这些脆弱而重要的生态系统有所了解。迫切需要在热带高海拔湖泊中进行更多研究。