A groundbreaking global synthesis has identified 603 species, genera, or families that significantly influence Earth's surface processes, shaping the landscapes we depend on. The study, led by Professor Gemma Harvey from Queen Mary University of London, highlights the diverse and extensive impact of animals on terrestrial and freshwater ecosystems. From tiny ants that displace soil to salmon that reshape riverbeds, the research reveals the remarkable ways animals act as 'natural engineers.'
Published in the Proceedings of the National Academy of Sciences (PNAS), the research estimates the collective energy of these animals, demonstrating that their geomorphic contributions rival those of hundreds of thousands of major floods. Key findings include:
Unexpected Diversity: Beyond well-known examples like beavers and salmon, the study identifies hundreds of species (including insects, mammals, fish, birds, and reptiles) that shape landscapes in significant ways.
Freshwater Ecosystems in Focus: Despite covering only 2.4% of the planet's surface, freshwater habitats are home to over a third of these notable species.
Impressive Energy Output: Animals collectively contribute at least 76,000 gigajoules of energy annually to shaping Earth's surface, comparable to hundreds of thousands of extreme floods. This estimate is likely conservative due to knowledge gaps, especially in tropical and subtropical regions.
Fascinating Examples: Termites build vast mound networks in Brazil, some covering thousands of square kilometers, while spawning salmon can move as much sediment as an annual flood. Even ants, through their small but numerous actions, alter soil structure and drainage.
Professor Harvey explains, "This research shows that the role of animals in shaping Earth's landscapes is far more important than previously thought. From beavers creating wetlands to ants building soil mounds, these diverse natural processes are crucial, but we risk losing them as biodiversity declines."
Nearly 30% of the identified species are rare, endemic, or threatened, meaning that vital geomorphological processes could cease before their full importance is understood. This loss could have profound consequences for the ecosystems and landscapes they support.