The Dolomites are a mountain group in the eastern Italian Alps, located almost entirely in the Regions of Veneto, Trentino-Alto Adige, and Friuli Venezia Giulia, with a small part also in Austria. The name of these mountains derives from the mineral that mainly composes that rock: the dolomite. This mineral was discovered in the late 18^th century by Marquis Déodat-Guy-Silvain-Tancrède Gratet de Dolomieu (1750-1801), who explored the southern Tyrol and collected rocks that were poorly effervescent when treated with acid, and thus it could not be calcium carbonate. In fact, the mineral dolomite is a double salt of calcium and magnesium, defined by the chemical formula MgCa(CO₃)₂, which is formed underground when limestone sediments are enriched with magnesium by saline water flows (Bosellini, 1989). It is exactly for this particular rock, which is very lighter in shade compared to nearby mountains, that the Dolomites are also called the “Pale Mountains”.

The Dolomites are among the most attractive mountain landscapes in the world. In June 2009, the Dolomites were declared a UNESCO World Heritage Site, for the geological importance and the uniqueness of their landscape. At an altitude of about 1,700 m, one encounters foothills covered with woodland and grasslands, from which large vertical masses of rock suddenly rise up, surrounded by debris deposits and interrupted by ledges and plateaus. That variety of spectacular forms derive from their geological origins, the processes that have shaped them, and the composition of the soils (Messner and Tappeiner, 2010). These shapes, along with the different territories surrounding them, constitute a complex mosaic of habitats, the backbone for the great biodiversity harbored.

The Dolomites belong to the most lichenologically well-known areas in Italy, whom interest is related to the variety of climatic conditions and substrates (Nimis, 1993). Trentino-Alto Adige, in particular, is the lichenologically richest Region of Italy, with 1673 infrageneric taxa of lichenised fungi reported to date, while 1231 taxa are known for Veneto and 1078 for Friuli (Nimis and Martellos, 2023).
This situation reflects the long history of lichenological exploration since the 19^th century. The majority of historical contributions are attributed to Ferdinand Arnold (1828-1901), who surveyed South Tyrol in the last years of the 1800s and published the results in the famous series Lichenologische Ausfluge in Tyrol (1868-1897). Another important contribution was provided by Ernst Kernstock (1852-1900) through the publication of his Lichenologische Beitrage (1890-1896). The lichen records from this region until 1901 were summarized by Dalla Torre and Sarnthein (1902) in one of the oldest known “checklists”: the monograph “Die Flechten (Lichenes) von Tirol, Vorarlberg und Liechtenstein”. In the first half of the 20^th century, these territories were mainly explored by Pio Bolzon (1867-1940) and Maria Cengia Sambo (1888-1939), who published several contributions on local lichen flora (Nimis, 1993).
Despite the lichenological interest of the Dolomites, no specific synthesis of their lichen diversity was ever attempted. Currently, it is available the checklist of the entire Alpine chain, updated to 2018 (Nimis et al., 2018), and the individual regional floras that can be inferred from ITALIC 7.0 (Nimis and Martellos, 2023), but neither of these are focused on the Dolomite area itself.
Field inventories (Spribille et al., 2020; Vondrák et al., 2016), reviewed herbarium specimens, and literature records (Himelbrant et al., 2018; Isocrono et al., 2007) are essential to lichen biodiversity research. They provide basic information on the distribution and ecology of species and sometimes trigger taxonomic advances, including the description of new species (Leavitt et al., 2021; Nascimbene et al., 2022; Spribille et al., 2020), fundamental for revealing biodiversity patterns and providing effective conservation guidelines. Under a global change scenario where many lichen species may face severe extinction risks, the absence of this dedicated synthesis could lead to the loss of hidden biodiversity even before its discovery.

Hence, in 2022 the Research Unit of Professor Nascimbene (University of Bologna) launched the Dolichens project, aimed at building a dynamic catalog of the lichen biota of the Dolomites region, by aggregating data from published and unpublished literature, and herbaria from the 19^th century to nowadays, augmented with new sampling campaigns, building a database made available online, which will be continuously updated and that will provide the basis for a critical and exhaustive checklist of the lichens of the Dolomites that will be compiled in the second step of the project.
We expect that this open data inventory will contribute to composing and maintaining the puzzle of a lichenological memory of the Dolomites, allowing us to track its lichen biota across ages, facing the challenge of rapid global changes.