Wetlands are among the most productive ecosystems in the world. Son related to biodiversity because one of its main functions is to retain and store waterWhich is important amid the water crisis the planet is going through.
Scientists from Chile and The Nature Conservancy (TNC) of Latin America conducted a study to test the potential of the Andean wetlands as a nature based solutions To deal with drought and water scarcity, which has affected the central region since 2010.
Due to climate change, there has been a decrease in rainfall and an increase in temperature. According to the data of the study, In the period 1990 and 2020 in the upper basin of the Maipo River, there was a statistically significant decrease in rainfall In monitoring stations on average 10 mm/yr.
That is why TNC Executive Director Juan José Donoso explains that “for water security it is important to promote the role of high Andean wetlands, which provide an ecosystem service of water regulation.”
study, which lasted eight years (2014 – 2022), monitored wetlands in the Maipo River Basin to improve understanding and assessment of these ecosystems in the face of climate change.
He mainly compared two basins: Casa Piedra Wetland and Aparejo Stream, This was because these sites are thought to be similar in terms of physical conditions: they are geographically adjacent, they are basins of similar size and have similar slopes. But they differ fundamentally in the presence of vege vegetation. The Casa Piedra Wetland has the Vega System and the Arroyo Stream does not.
“The wetland has a range of characteristics and creates a whole situation in that part of the basin that is opposite to the Aparejo stream, which is similar to the others but is not a wetland. Y This is what then allows one to scientifically contrast what effect the basin has on being a wetland”.Says TNC executive director.
Wetlands play a fundamental role in water supply, as they contain a Regulatory effect that reduces maximum flood flow and increases minimum base flow during drought.
Moderation in maximum flow makes it possible to preserve the banks and hydraulic works located downstream, and significantly reduce sediment drag.
The measurements of the study allowed us to verify that the Casa Piedra wetland, which has vegetation typical of high Andean wetlands, Acts as a filter, retaining sediment of water coming down the mountain range and filtering it on its way to El Yeso Reservoir; and at the same time like a sponge, retains these waters with its soil and vegetation in the spring, and release them into the basin during the summer season (January to March), when it is most needed.
In this sense, its sponge function allows water to be stored and supplied to people when they need it most. Total amount of water stored in Casa Piedra wetlands It has the capacity to supply 8,877 people in a year, according to study data
“This is for a specific wetland, but it allows us to extrapolate it to the whole basin and to management that can be done across the country”, comments Donoso. Regarding outflow of Casa Piedra wetlands during the summer season It can supply 500,000 people per day and 216,000 in winter.
Furthermore, during hydrological years in which less precipitation was recorded, the base flow of water in the Casa Piedra wetland was higher than in Aparejo. This is beneficial, as it allows for higher minimum flows during dry years.
“It is a solution that nature gives us to take care of, in this case, the climate crisis we are facing”Donoso says.
lakes Considered a fragile ecosystem and may be affected by natural causes Such as extreme drought, strong winds, high radiation and large thermal amplitude. But also due to human factors, such as overgrazing, agriculture, mining or extraction of water for human consumption, as well as modification of water courses.
This is why the study mentions the importance of surveying and conserving wetlands The better its condition, the greater its positive effectsLike the aforementioned sponge effect.
the first necessary step would be control grazing and cattle loadsand allow the rest of the vegetation associated with the meadow and vegas to produce seed and germinate for the next season, as grazing eliminates seed production, compacts the soil and leads to the death of this vegetation Is.
“Conservation and restoration work arising in these areas has tangible rewardsWater security is showing the greatest increase not only in the flora and fauna of the region, but also in the well-being of the populations concerned, the study said.
Another necessary measure would be Control tourism and high impact practices in these ecosystems, such as 4×4 vehicular traffic on their surface. In this way, work can be done to restore these wetlands, supplementing them with water that promotes the growth of their characteristic vegetation, a process that uses the same water that thaws from the mountains. comes
The TNC executive director points out that there is still a lack of public policies aimed at conserving wetlands: “There is still a long way to go to include them forcefully, and in general the strategies in charge of what we are experiencing How do we take the planet, both the crisis such as the loss of biodiversity, the climate crisis, and especially in our central region, the water crisis is very important”.
“If you don’t know the value of something, it is very difficult to keep it”Donoso ends.