The findings, published in Biological Conservation, challenge one of the longest-standing assumptions in European ecology about what the continent looked like before humans transformed the landscape.

Rather than being covered by continuous closed-canopy forests, researchers say Central Europe was dominated for around 23 million years by a "forest-pasture" mosaic—a shifting mix of dense woodland, open forests, clearings, meadows and grasslands.

Ancient elephants, rhinos, wild horses, bison and the ancestors of modern deer helped shape this landscape by browsing young trees, breaking branches and trampling vegetation, preventing forests from closing over and maintaining a rich diversity of habitats.

"Our synthesis challenges the long-established paradigm of closed-canopy forests," the authors write.

The study was led by Szymon Czyżewski, a graduate of the Institute of Zoology and Biomedical Research at Jagiellonian University who is now a doctoral researcher at Aarhus University in Denmark. Jagiellonian researchers Karol Wałach and Dr. Bartłomiej Zając also contributed to the research.

To reach their conclusions, the researchers combined multiple lines of palaeoecological evidence rather than relying solely on fossil pollen, the traditional method of reconstructing ancient environments. Their analysis included carbon isotopes preserved in fossil mammal bones, tooth-wear patterns that reveal feeding behaviour, fossils of dung beetles indicating the presence of large grazing herds, and evidence from the Eemian interglacial around 130,000 to 115,000 years ago, when Europe's climate was similar to today's but human influence was minimal.

The researchers argue that the extinction of many large herbivores at the end of the Pleistocene and the beginning of the Holocene fundamentally reshaped Europe's ecosystems. Without these animals to keep vegetation in check, forests became denser, altering biodiversity and ecosystem functioning.

According to the study, today's extensive closed-canopy forests are themselves a relatively recent feature of the European landscape, emerging only after many large herbivores disappeared along with the ecological processes they sustained.

Although agriculture and livestock later replaced some of the role once played by wild grazers, the resulting landscapes were far simpler than the natural mosaic that had existed for millions of years.

The findings could reshape conservation strategies by shifting the focus from preserving closed forests to restoring the natural ecological processes—including the role of large herbivores—that helped sustain Europe's biodiversity for millions of years. Rather than recreating ancient landscapes exactly as they once were, the researchers argue that conservation should seek to restore the ecological dynamics that made those ecosystems so resilient. (PAP)

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