AFP – Animals don’t just live in nature – they transform it.
A recent study in Britain, published in Proceedings of the National Academy of Sciences (PNAS), highlights how hundreds of species actively shape land and water ecosystems.
From termites building towering mounds visible from space to hippos carving natural drainage channels, these “ecosystem engineers” have a far greater impact on the environment than we often realise.
Led by Professor Gemma Harvey of Queen Mary University of London, researchers identified 603 species, genera, or families that influence soil and waterways.
Their actions range from tiny ants moving grains of earth to salmon dramatically reshaping riverbeds during spawning.
The researchers estimate that animals contribute at least 76,000 gigajoules of energy per year to shaping the Earth’s surface, equivalent to several hundred thousand major floods.
This figure is probably an underestimate, as there are still significant gaps, particularly in tropical and subtropical regions where biodiversity is richest, but where research remains limited.
One of the most striking discoveries of this study concerns the impact on freshwater ecosystems. Although they cover only 2.4 per cent of the Earth’s surface, they are home to more than a third of these influential species.
Termites, for example, build impressive structures in the Amazon and Africa that promote water circulation and regulate the local temperature. Beavers, for their part, play an essential role in water retention and soil preservation, thus helping to limit erosion.
This study highlights the essential role animals play in maintaining natural balances, while revealing a worrying reality.
Nearly 30 per cent of the species identified are rare, endemic or endangered. For example, the population of Atlantic salmon has halved in 20 years, according to estimates.
This decline can be explained by several factors, including overfishing, climate change, the destruction of their habitats and the spread of disease from salmon farms.
If these species were to disappear, certain essential geomorphic processes could be lost even before their importance is fully understood.
“This research shows that the role of animals in shaping Earth’s landscapes is much more significant than previously recognised.
“From beavers creating wetlands to ants building mounds of soil, these diverse natural processes are crucial, yet we risk losing them as biodiversity declines,” Professor Harvey said in a statement.
Beyond its scientific contribution, this study opens up new perspectives for the preservation of ecosystems. The reintroduction of key species, such as beavers in Europe, which restore wetlands, could prove to be an effective strategy in the face of climate change and the intensification of natural disasters.
Indeed, protecting nature’s architects helps safeguard the landscapes they have been sculpting for millennia.
