Cinvestav, Department of Biotechnology and Bioengineering, Mexico City, Mexico.
Universidad Nacional Autónoma de México, Departamento de Ecología Evolutiva, Mexico City, Mexico.
Sci Total Environ. 2019 May 20;666:1255-1264. doi: 10.1016/j.scitotenv.2019.02.163. Epub 2019 Feb 19.
The Cuatro Cienegas Basin (CCB) in the Chihuahuan desert is characterized by the presence of over 500 ponds located in an endorheic basin. These ponds are subsaline ecosystems characterized by a low productivity and a particularly high sulfate concentration, comparable to marine environments. This study focused on assessing the main physicochemical parameters in these ponds along with the characterization of the CH dynamics through the determination of fluxes, dissolved CH concentrations, and net methanotrophic and methanogenic activity. Despite a sulfate concentration ranging from 1.06 to 4.73 g L, the studied ponds showed moderate but clear CH production and emission, which suggests that methanogenesis is not completely outcompeted by sulfate reduction. CH fluxes ranged from 0.12 to 0.98 mg m d, which falls within the higher range of marine emissions and within the lower range reported for coastal saline lagoons and saline ponds. During summer, significant CH production in the oxic water column was observed. In addition to CH, CO fluxes were determined at levels from 0.2 to 53 g m d, which is within the range recorded for saline lakes in other parts of the world. Our results provide additional evidence that subsaline/saline aquatic ecosystems play an important role in the emission of greenhouse gases to the atmosphere.
四泉谷盆地（CCB）位于奇瓦瓦沙漠，其特点是在一个内流盆地中有 500 多个池塘。这些池塘是亚盐生生态系统，具有低生产力和特别高的硫酸盐浓度，与海洋环境相当。本研究重点评估了这些池塘的主要理化参数，并通过测定通量、溶解 CH 浓度以及净甲烷氧化和甲烷生成活性，对 CH 动态进行了表征。尽管硫酸盐浓度范围在 1.06 至 4.73g/L 之间，但研究中的池塘表现出适度但明显的 CH 产生和排放，这表明甲烷生成并未完全被硫酸盐还原所抑制。CH 通量范围在 0.12 至 0.98mg/m2/d 之间，处于海洋排放的较高范围，也处于沿海盐沼和盐水池塘报道的较低范围之内。在夏季，观察到好氧水柱中存在显著的 CH 产生。除了 CH 之外，还测定了 CO 通量，范围在 0.2 至 53g/m2/d 之间，这在世界其他地区的盐水湖中也有记录。我们的结果提供了更多证据，表明亚盐生/盐生水生生态系统在温室气体向大气排放中发挥着重要作用。
