Departamento de Biología, Observatorio de Ecología Microbiana, Facultad de Ciencias Naturales y Exactas, Universidad de Playa Ancha, Avenida Leopoldo Carvallo 270, Playa Ancha, Valparaíso 2340000, Chile; HUB Ambiental UPLA, Universidad de Playa Ancha, Avenida Leopoldo Carvallo 200, Playa Ancha, Valparaíso 2340000, Chile.
Instituto de Química y Bioquímica, Facultad de Ciencias, Universidad de Valparaíso, Gran Bretaña 1111, Playa Ancha, Valparaíso 2360102, Chile.
Sci Total Environ. 2021 May 10;768:144370. doi: 10.1016/j.scitotenv.2020.144370. Epub 2020 Dec 30.
The landscapes of high-altitude wetland ecosystems are characterized by different kinds of aquatic sites, including ponds holding conspicuous microbial life. Here, we examined a representative pond of the wetland landscape for dynamics of greenhouse gases, and their association with other relevant biogeochemical conditions including diel shifts of microbial communities' structure and activity over two consecutive days. Satellite image analysis indicates that the area of ponds cover 238 of 381.3 Ha (i.e., 62.4%), representing a significant landscape in this wetland. Solar radiation, wind velocity and temperature varied daily and between the days sampled, influencing the biogeochemical dynamics in the pond, shifting the pond reservoir of inorganic versus dissolved organic nitrogen/phosphorus bioavailability, between day 1 and day 2. Day 2 was characterized by high dissolved organic nitrogen/phosphorus and NO accumulation. CH presented a positive excess showing maxima at hours of high radiation during both days. The microbial community in the sediment was diverse and enriched in keystone active groups potentially related with GHG recycling including bacteria and archaea, such as Cyanobacteria, Verrucomicrobia, Rhodobacterales and Nanoarchaeaota (Woesearchaeia). Archaea account for the microbial community composition changes between both days and for the secondary productivity in the water measured during day 2. The results indicate that an intense recycling of organic matter occurs in the pond systems and that the activity of the microbial community is correlated with the availability of nutrients. Together, the above results indicate a net sink of CO and NO, which has also been reported for other natural and artificial ponds. Overall, our two-day fluctuation study in a representative pond of a high-altitude wetland aquatic landscape indicates the need to explore in more detail the short-term besides the long-term biogeochemical variability in arid ecosystems of the Andes plateau, where wetlands are hotspots of life currently under high anthropogenic pressure.
高山湿地生态系统的景观以各种不同的水生场所为特征，包括容纳明显微生物生命的池塘。在这里，我们研究了湿地景观中一个具有代表性的池塘，以了解温室气体的动态及其与其他相关生物地球化学条件的关系，包括连续两天微生物群落结构和活性的昼夜变化。卫星图像分析表明，池塘面积占 381.3 公顷湿地的 238 公顷（即 62.4%），是该湿地的一个重要景观。太阳辐射、风速和温度每天都在变化，并且在采样的两天之间也在变化，影响了池塘中的生物地球化学动力学，在第一天和第二天之间改变了池塘中无机与溶解有机氮/磷生物利用度的水库。第二天的特点是溶解有机氮/磷和 NO 的积累增加。CH 呈现正过剩，在两天的高辐射时段达到最大值。沉积物中的微生物群落多样，富含与 GHG 循环有关的关键活跃群，包括细菌和古菌，如蓝细菌、疣微菌、红杆菌目和 Nanoarchaeota（沃氏古菌）。古菌解释了微生物群落组成在两天之间的变化，以及第二天测量的水中的二次生产力。结果表明，池塘系统中发生了强烈的有机物循环，微生物群落的活性与养分的可利用性相关。总的来说，这些结果表明，CO 和 NO 的净汇也已经在其他自然和人工池塘中得到了报道。总体而言，我们对高山湿地水生景观中一个具有代表性的池塘进行了为期两天的波动研究，这表明需要更详细地探索除了安第斯高原干旱生态系统的长期生物地球化学变异性之外，短期生物地球化学变异性，在那里湿地是当前受到高度人为压力的生命热点。
