Trait- and environment-based determinants of reproduction in the old forest indicator lichen Lobaria pulmonaria

) and rapid growth rates exhibited reduced reproductive activity. Environmental stressors, such as high-light-induced chlorophyll bleaching and elevated altitude, weakly inhibited soralia development. Sexual reproduction was rare, with apothecia present in only 2% of transplants and no new apothecia forming during the study. The findings highlight the slow pace of soralia formation and, coupled with the species' long generation time, suggest that current forest rotation cycles in managed forests may be insufficient to sustain viable L. pulmonaria populations. Conservation strategies should therefore account for both slow reproductive onset and sensitivity to environmental conditions.