Inland aquatic ecosystems (rivers, lakes, wetlands) are experiencing a alarming decline due to human-induced disturbance. Pollution, the introduction of invasive species and the destruction of habitats threaten the functioning, integrity and biodiversity of these ecosystems, which are considered the most sensitive and threatened on the planet.
Aquatic plants perform essential functions to ensure the natural dynamics of freshwater ecosystems, especially in the face of the growing impacts of climate change, according to a recent study that we conducted.
Pillars of Aquatic Life
These photosynthetic organisms are considered to be the “engineers” of their ecosystems, providing food and shelter for terrestrial and aquatic animals. They also control sedimentation and erosion processes in coastal areas and are a central element of the carbon and nitrogen cycles in inland waters.
Aquatic plants, such as water lilies, pontederies or cattails, exhibit unique adaptations to life in water. These adaptations allowed them to colonize, grow and survive in temporarily or permanently flooded areas.
Having divided leaves with thin protective cuticles and a very low proportion of woody tissue in their physical structures allows these plants to optimize photosynthesis and gas exchange in the aquatic environment.
(Yingji Pan, Jorge García-Girón, Lars Lønsmann Iversen), Author provided
Threatened by human action
Aquatic plants are threatened by the combined and synergistic action of multiple stressors associated with human activities.
Our study highlights how pollution from urban and agricultural runoff, dam construction, and severe seasonal droughts, among others, compromise the survival of aquatic plants in their environments, thereby threatening the integrity and persistence of ecosystems. freshwater around the world.
For example, the construction of dams disrupts the longitudinal connectivity of rivers, interfering with the natural biotic fluxes that ensure the diversity of landscapes.
Prolonged droughts favor an accelerated shift from communities dominated by submerged and floating plants to environments in which only a few individuals of fast-growing emergent species thrive.
Big unknowns
The limited biological information available for this group of plant species prevents scientists from delimiting, defining and predicting the responses of aquatic plants to the environmental disturbances in which we are currently immersed.
In this regard, the scientific community has warned for some time on the need to join forces to study in depth the biology of these key organisms for the functioning of inland waters.
So far, however, we only haveecological information only for a tiny part of the more than 3,400 species of aquatic plants in the world. By way of comparison, data are already available and computerized for more than 46,000 species of terrestrial plants.
The profound ignorance of the biology of aquatic plants is even more dramatic outside the borders of Europe and North America, especially in the subtropical zones where these particular organisms enjoy the greatest diversity.
The authors of this brief study point out that ignoring this reality not only undermines our models for predicting possible scenarios of global change for freshwater ecosystems, but also jeopardizes the very survival of rivers and wetlands. that surround us and provide us with services of great social and economic value.
It is time to reverse botanical blindness, which affects both members of the scientific community and society as a whole, and to recognize aquatic plants as a cornerstone in the conservation and protection of the world’s most threatened ecosystems. planet.
