Modeling long-term dynamics of carbon dioxide and oxygen in high-altitude wetlands.

Altiplanic wetlands are located above 3000 m.a.s.l. in endorheic basins in South America. Extreme environmental conditions and great ecological value characterize these systems. However, they are threatened because they host great mineralogical wealth. In addition, climate change could impact these environments, unbalancing water cycles and biochemical processes. High-altitude wetlands play a key role in recycling greenhouse gasses through microbial activity, which can alter the effects of meteorological forcings. To analyze these effects, we constructed a transient 0-D model that simulates interphase mass fluxes and biochemical processes related to CO2 and O2 in the Salar del Huasco wetland, corresponding to a protected wilderness area in northern Chile. This article aims to study the influence of climatic trends of meteorological variables in high-altitude wetland and their relationship with CO2 and O2 dynamics. The model allows studying the long-term behavior of control variables independent of initial conditions and at different time scales. The results indicate that mass transport of CO2 and O2 across the air-water interface dominates variations of the concentrations in the column water. Atmospheric forcings were shown to influence mass transport and water quality in high-altitude wetlands , with wind speed being one the most significant factors. It is important to note that when talking about climate change, emphasis is usually placed on the increase of the ambient temperature; however, it is shown that it is relevant to consider the variation of the wind regime High-altitude wetlands.