INFI 2025: A Strategic Tool for Forest Biodiversity Research and Conservation

The new Italian National Forest Inventory (INFI 2025)[1] represents a major advancement over the previous three national forest inventories, substantially expanding the range of information collected and strengthening the role of the inventory as a strategic tool for large-scale biodiversity monitoring. INFI 2025 adopts a two-phase rotating sampling strategy. In the first phase, forest and non-forest points are classified through on-screen land cover interpretation supported by multiple remote sensing data sources. In the second phase, sample points are revisited according to a five-year rotation system (panels). In 2025 (panel 1), field measurements are conducted on 1370 plots distributed across the entire national territory. Both qualitative and quantitative data are collected on-site (e.g., stand health, deadwood, dendrometric and silvicultural attributes). For the first time, Tree-related Microhabitats (TreMs) are also recorded, following recent European standards for biodiversity monitoring and environmental reporting. The main innovation of IFNI 2025 lies in the introduction of: i. a novel protocol for understory plant functional groups (lichens, bryophytes, pteridophytes, forbs, grasses, and woody species), conducted by personnel of the Carabinieri Command of Forestry, Environmental and Agri-Food Unit (CUFAA) in the second phase sample points; ii. a third phase sample (10% of the second phase sample) dedicated to ecological surveys of vascular plants. The newly collected data provide unprecedented opportunities to investigate multiple dimensions of biodiversity components that had not previously been recorded in the Italian national forest inventories, such as vascular plants. They enable analyses of multiple dimensions of plant diversity, including designed based estimates of species richness, beta diversity, and large-scale biogeographic patterns. They also allow for the systematic assessment of species of conservation concern, including taxa listed in red lists (www.IUCN.it), alien species, and forest endemics[2]. These data enable quantification of how effectively the INFI 2025 sampling design captures these biodiversity components, and identification of areas of high conservation value, invasion risk, and endemic richness across the country. The inclusion of Tree-related Microhabitats represents another highly significant innovation. TreMs are key structural features that provide habitat for a wide range of organisms, including birds, bats, and saproxylic insects[3]. Their occurrence reflects forest structural complexity and habitat availability. For the first time in Italy, it will be possible to assess the distribution, richness, and diversity of TreMs at the national scale, comparing biogeographic regions, forest types, and management conditions to evaluate the capacity of Italian forests to support biodiversity. All these innovations orient INFI 2025 into a comprehensive national infrastructure for integrated forest biodiversity monitoring. By combining structural, taxonomic, and biogeographic information, it provides an unprecedented baseline for ecological research, conservation planning, and evidence-based forest management and biodiversity policies.