This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: A study in Pollino National Park shows that large trees, complex canopies and deadwood diversity play a major role in shaping vascular plant communities, highlighting the ecological value of one of Italy's most remarkable old-growth forest landscapes. Old-growth forests are among Europe's rarest and most valuable ecosystems, providing refuges for biodiversity while storing carbon and maintaining complex ecological processes capable of buffering pressures from global change.
Yet scientists are still working to understand what determines their extraordinary biological diversity, particularly in Mediterranean mountain environments. A new study published in Ecology and Evolution has found that forest structural attributes are more strongly associated with vascular plant composition than topography alone in old-growth forests of Pollino National Park in southern Italy. The research, led by Danilo Travascia of the University of Basilicata and involving researchers from several Italian universities and Pollino National Park, examined old-growth stands representing different forest types across the Southern Apennines.
The team surveyed nine candidate old-growth forest sites, ranging from Mediterranean and mixed deciduous stands to high-elevation beech forests. The final analyses included 142 subplots across eight sites, integrating detailed measurements of forest structure, topography and vascular plant composition. Rather than relying on a single indicator of forest maturity, the researchers combined multiple complementary approaches.
Structural complexity was summarized through a Structural Heterogeneity Index (SHI), while mixed-effects models and multivariate analyses—including canonical correspondence analysis, principal coordinate analysis and variation partitioning—were used to disentangle the relationships among forest structure, topography and plant communities. The robustness of the floristic analyses was also tested through sampling-completeness and sensitivity analyses. "One of the main strengths of our study is that we did not treat old-growth character as a single structural feature.
By combining measurements of living trees, large-diameter trees, canopy structure and deadwood with floristic and topographic data, we were able to separate the contribution of forest structure from that of topography and examine how structural differences are associated with vascular plant communities," said Danilo Travascia, first author, University of Basilicata The field campaign involved detailed structural and floristic surveys in forests that are often remote and characterized by complex terrain. Living trees, regeneration, standing and downed deadwood, coarse woody debris and decay stages were recorded alongside vascular plant composition and topographic variables. The study derived 24 structural variables from these measurements.
"This study depended on the quality and consistency of field observations. Working in the old-growth forests of Pollino brought together park managers and forestry and botanical expertise, applying harmonized protocols across sites that differ greatly in altitude, species composition and accessibility. By surveying living trees, regeneration, canopy attributes, deadwood and the entire vascular flora at the same spatial scale, we could analyze each stand as an integrated ecological system," said Francesco Ripullone, senior author, University of Basilicata Discover the latest in science, tech, and space with over 100,000 subscribers who rely on Phys.org for daily insights. d research that matter—daily or weekly.
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