[in Italian with English abstract: ] This book aims to study the specific biodiversities of lichens of a Tuscany area named “Alta-Valdera”. In particular we would like to share interesting findings in this territory where the concentration of the CO2 increases over the normal limit because of the emission of natural gasses from the underground. The vent of this emission is positioned inside the forest of the “Mofeta of Borboi” at Orciatico/Lajatico Municipality. We researched and documented 34 lichen species in all that territory. The “core” of the book points to that species of the lichens resistant to the stressful conditions of life near the natural gas emission vent. We found five species of resistant lichens: Flavoparmelia caperata, Cladonia sp., Pertusaria amara, Parmelia perlata, Evernia prunastri. In addition to a photographic documentation we liked to put the analysis of fine lichen structures analyzed under optical microscope. At last but not the least we discovered an important niche of lichen colonies in the area of “Mulino Fonterossa” which we suggest to protect from the human intervention. In the final chapter we propose a “miscellanea” of environmental biodiversties and some landscape of the beautiful country Alta Valdera in Tuscany.