Integrating dark diversity and functional traits to enhance nature conservation of epiphytic lichens: a case study from Northern Italy

Abstract Mountains provide a timely opportunity to examine the potential effects of climate change on biodiversity. However, nature conservation in mountain areas have mostly focused observed part biodiversity, not revealing suitable but absent species—dark diversity. Dark diversity allows calculating community completeness, indicating whether sites should be restored (low completeness) or conserved (high completeness). Functional traits can added, showing what groups on. Here we assessed changes taxonomic and functional dark epiphytic lichens along elevational transects Northern Italy spruce forests. Eight (900–1900 m) were selected, resulting 48 plots 240 trees, which sampled using four quadrats per tree (10 × 50 cm). was estimated based species co-occurrence (Beals index). We considered related growth form, photobiont type reproductive strategy. Linear Dirichlet regressions used metrics gradient. Our results showed that all increased with elevation differed between At low elevations, due completeness harsh conditions, both restoration activities are needed, focusing crustose species. Towards high is more important prevent pool losses, macrolichens, Trentepohlia sexual reproduction. Finally, novel tool enhance conservation, particular threatened groups, creating windows opportunities protect from local regional extinctions.