While environmentalists venerate them, most humans are unaware of the benefits provided by the wetlands that cover the Earth. As they are unsuitable for human activities, mankind wanted to quickly transform them to make them suitable for agriculture and urban development. Unfortunately, today, scientists estimate that 64% of the planet’s wetlands have disappeared since 1900, and the consequences are not limited to this fact1. Between 1975 and 2015, 76% of freshwater plant and animal populations became extinct. Humankind has a duty to raise its awareness of this reality1. Did you know that these natural environments are disappearing 3 times faster than forests2?
In 2017, the government of Quebec took the initiative by passing “An Act respecting the conservation of wetlands and bodies of water” 3. This initiative was intended to be a starting point for the protection, the restoration and the sustainable management of these zones. Today, these environments occupy around 11% of Quebec’s territory, but, as elsewhere in the world, most of them remain under threat4.
Before taking steps to protect this wealth, we must first learn to recognize and understand it. There are three key elements that help define a wetland: hydrology (the degree of flooding), vegetation and soil type5. An important aspect to remember about these areas is their evolution over time. These zones are permanently or temporarily immersed or soaked in water. As a result, their surface area, degree of humidity and plant composition vary according to a number of external factors, such as the seasons, weather conditions, and climate5. Wetlands are divided into four broad categories: ponds, marshes, swamps and peatlands. Each of them has distinct characteristics that give it specific ecological functions.
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Ponds | Swamps |
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Marshes | Peatlands |
Now, let’s look at the ecological roles of these areas:
Water-level Regulation
Wetlands act like giant sponges. They absorb water during periods of intense precipitation (rain or snowmelt) and gradually redistribute it during dry spells. This retention capacity helps to control floods and prevents erosion6. Moreover, some soils are particularly effective in replenishing underground aquifers7.
Water Biofiltration
Nicknamed nature’s kidneys, wetlands naturally filter the water passing through them thanks to their high plant density. Plant species that live in these areas, such as cattails, contribute to the elimination of phosphate and other nutrients, thus slowing down the proliferation of harmful algae and aquatic weeds6. In addition, pollutants contained in sediments, once deposited on the ground, are degraded by the microbial activity that is naturally present in these environments8.
Rich in Biodiversity
Wetlands are home to many animal, plant and microbiological species. In fact, as they can shelter and feed there, 40% of the world’s species live or reproduce in wetlands7! Without the existence of these lands, many living organisms would be at risk of extinction.
Carbon Sequestration
Wetlands play an important role in the fight against climate change. In addition to performing the essential functions mentioned above, they are among the most effective ecosystems for capturing and storing carbon. Peatlands, in particular, stand out in this respect. This type of wetland occupies almost 3% of our planet’s land but stores around 30% of all land-based carbon9!
Water Cooling
Wetlands also help to cool down the water that flows through them. It is their abundant vegetation that helps lower water temperatures. This, in turn, helps reduce the risk of algal blooms7.
In summary, although these areas may seem useless and of little value at first glance, they are, on the contrary, a precious ecological resource whose protection should be a priority.