Molina Verónica, Eissler Yoanna, Cornejo Marcela, Galand Pierre E, Dorador Cristina, Hengst Martha, Fernandez Camila, Francois Jean Pierre
Programa de Biodiversidad y Departamento de Biología, Facultad de Ciencias Naturales y Exactas, Observatorio de Ecología Microbiana, Universidad de Playa Ancha, Valparaíso, Chile.
Centro de Investigación y Gestión de Recursos Naturales, Instituto de Química y Bioquímica, Universidad de Valparaíso, Valparaíso, Chile.
Antonie Van Leeuwenhoek. 2018 Aug;111(8):1421-1432. doi: 10.1007/s10482-018-1078-9. Epub 2018 Apr 6.
Northern Chile harbors different bioclimatic zones including hyper-arid and arid ecosystems and hotspots of microbial life, such as high altitude wetlands, which may contribute differentially to greenhouse gases (GHG) such as carbon dioxide (CO), methane (CH) and nitrous oxide (NO). In this study, we explored ground level GHG distribution and the potential role of a wetland situated at 3800 m.a.s.l, and characterized by high solar radiation < 1600 W m, extreme temperature ranges (-12 to 24 °C) and wind stress (< 17 m s). The water source of the wetland is mainly groundwater springs, which generates streams and ponds surrounded by peatlands. These sites support a rich microbial aquatic life including diverse bacteria and archaea communities, which transiently form more complex structures, such as microbial mats. In this study, GHG were measured in the water and above ground level air at the wetland site and along an elevation gradient in different bioclimatic areas from arid to hyper-arid zones. The microbiome from the water and sediments was described by high-throughput sequencing 16S rRNA and rDNA genes. The results indicate that GHG at ground level were variable along the elevation gradient potentially associated with different bioclimatic zones, reaching high values at the high Andean steppe and variable but lower values in the Atacama Desert and at the wetland. The water areas of the wetland presented high concentrations of CH and CO, particularly at the spring areas and in air bubbles below microbial mats. The microbial community was rich (> 40 phyla), including archaea and bacteria potentially active in the different matrices studied (water, sediments and mats). Functional microbial groups associated with GHG recycling were detected at low frequency, i.e., < 2.5% of total sequences. Our results indicate that hyper-arid and arid areas of northern Chile are sites of GHG exchange associated with various bioclimatic zones and particularly in aquatic areas of the wetland where this ecosystem could represent a net sink of NO and a source for CH and CO.
智利北部拥有不同的生物气候区，包括极度干旱和干旱的生态系统以及微生物生命热点地区，如高海拔湿地，这些地区可能对二氧化碳（CO）、甲烷（CH）和一氧化二氮（NO）等温室气体（GHG）有不同的贡献。在本研究中，我们探索了海拔3800米处湿地的地面温室气体分布及其潜在作用，该湿地的特点是太阳辐射高<1600 W m，极端温度范围为（-12至24°C）且风应力<17 m s。该湿地的水源主要是地下水泉，形成了被泥炭地环绕的溪流和池塘。这些地点支持丰富的微生物水生生物，包括多样的细菌和古菌群落，它们会短暂形成更复杂的结构，如微生物垫。在本研究中，在湿地现场以及从干旱到极度干旱区的不同生物气候区域的海拔梯度上，对水中和地面以上空气中的温室气体进行了测量。通过高通量测序16S rRNA和rDNA基因描述了水和沉积物中的微生物群落。结果表明，地面温室气体沿海拔梯度变化，可能与不同的生物气候区有关，在安第斯高草原达到高值，而在阿塔卡马沙漠和湿地则变化但较低。湿地的水域中CH和CO浓度较高，特别是在泉水区域和微生物垫下方的气泡中。微生物群落丰富（>40个门），包括可能在研究的不同基质（水、沉积物和垫子）中活跃的古菌和细菌。与温室气体循环相关的功能性微生物群检测频率较低，即占总序列的<2.5%。我们的结果表明，智利北部的极度干旱和干旱地区是与各种生物气候区相关的温室气体交换场所，特别是在湿地的水生区域，该生态系统可能是NO的净汇以及CH和CO的源。
