A recent study in Pollino National Park has revealed that the physical structure of forests plays a more significant role in supporting a wide variety of vascular plants—like flowers, shrubs, and trees—than the natural landscape features such as hills and valleys. This research, led by Danilo Travascia from the University of Basilicata and involving several Italian universities and the park, examined nine old-growth forest sites across different forest types. The scientists collected data from 142 subplots, measuring various aspects of the forest, including the arrangement of trees, the presence of deadwood, and the diversity of plant life. To understand how forest structure and topography influence plant life, the researchers developed a Structural Heterogeneity Index (SHI) to measure how complex the forest is. They used advanced statistical methods to analyze how these factors interact. The study found that while topography does shape the forest, it only explains about 18.8% of the variation in the forest’s structure. In contrast, the structure of the forest itself had a stronger effect on plant diversity, contributing 23.5% to the variety of vascular plants, compared to 12.8% from topography alone. Key structural elements that support diverse plant life include the number of large trees, the complexity of the tree canopy, the density and variety of tree species, and the presence of decaying wood in different stages. These features create a variety of light conditions, microclimates, and soil types that allow different plants to thrive. The researchers identified 153 different vascular plant species across the study area, with an estimated total of about 170 species. These plant communities varied significantly depending on the dominant tree species, such as beech, oak, and maple. The study also emphasizes that the number of species in a forest is not the only measure of its ecological value. Forests that have experienced repeated disturbances, such as fires or logging, may have more species, but those species are often common, adaptable plants that thrive in disturbed environments. In contrast, undisturbed old-growth forests support unique plant communities that have developed over long periods, maintaining ecological continuity and preserving species that are rare or have specific habitat needs. The researchers recommend long-term studies that combine measurements of forest structure, plant life, and environmental factors like soil and climate. They suggest using tools such as tree ring analysis, satellite imaging, and detailed soil surveys to better understand how these forests function. Pollino National Park, with its diverse range of forest types and long-term ecological stability, offers a unique opportunity to study how Mediterranean mountain forests respond to climate change and how best to protect them.