Impact of forest management on threatened epiphytic macrolichens: evidence from a Mediterranean mixed oak forest (Italy)

Forest management practices may heavily affect epiphytic cryptogams. This study was conceived in March 2016, as soon as we were informed about an authorized logging for timber within a Mediterranean mixed oak forest in Tuscany (central Italy), which threatened a large population of the forest macrolichen Lobaria pulmonaria (L.) Hoffm., composed of hundreds of fertile thalli. Lobaria pulmonaria is often used as an ecological indicator of high quality habitats hosting rare lichens, and in general, cryptogams worthy of conservation. The species has suffered a general decline throughout Europe as a consequence of air pollution and intensive forest management, and currently it is red-listed in several countries, where it is considered also as a “flag species”. We estimated that 40% of the lichen biomass (8.5-12.3 kg ha-1) has been lost due to logging operations (in the core area, up to 1.8 kg every 100 m2), in particular large and fertile thalli. One year after the conclusion of logging operations, the analysis of chlorophyll fluorescence emission (indicator of the photosynthetic performance of the lichen photobionts), revealed a significant reduction of the vitality of the thalli on retained-isolated trees. The article provides issues for conservation in Mediterranean oak forests and outlines the outmost importance of ensuring the safeguard of forest ecosystems hosting fertile populations of this model species, especially in the case of unprotected forests.