The Italian lichens dataset from the TSB herbarium (University of Trieste)

Abstract Background The "Herbarium Universitatis Tergestinae" (TSB), with a total of ca. 50,000 specimens, includes the largest modern collection of lichens in Italy, with 25,796 samples collected from all over the country since 1984, representing 74% of all taxa known to occur in Italy. Almost all specimens have been georeferenced “a posteriori”. The dataset is available through GBIF, as well as in ITALIC, the Information System of Italian Lichens. New information The TSB Herbarium hosts the largest modern lichen collection in Italy, with a total of ca. 50,000 specimens. This dataset contains all of the 25,796 specimens collected within the administrative borders of Italy. Amongst them, 98% are georeferenced and 87% have the date of collection. The dataset includes several type specimens (isotypes and holotypes) and exsiccata.


New information
The TSB Herbarium hosts the largest modern lichen collection in Italy, with a total of ca.50,000 specimens.This dataset contains all of the 25,796 specimens collected within the administrative borders of Italy.Amongst them, 98% are georeferenced and 87% have the date of collection.The dataset includes several type specimens (isotypes and holotypes) and exsiccata.‡ ‡ ‡ ‡ ‡ ‡

Introduction
Herbaria are an important source of falsifiable biodiversity data; stored specimens can be used to validate observations (Willis et al. 2017), to provide data for the assessment of Red Lists (Callmander et al. 2005, Nascimbene et al. 2012), to obtain DNA for answering questions of evolution, genetic diversity etc. (Taylor and Swann 1994) and to depict the presence of a taxon in a specific space and time.Geo-referenced data obtained from specimens can be used in distribution modelling and biogeographic studies to assess the past extent of a taxon (Marsico et al. 2020, Albani Rocchetti et al. 2021), to depict its current distribution and to predict potential range shifts in a global changes scenario (Loiselle et al. 2008, Attorre et al. 2018, Meineke et al. 2018, Lang et al. 2019).
Before the publication of the TSB Herbarium dataset, querying the GBIF (2022) for lichen occurrences in Italy returned about 12,000 records, none of which came from an Italian herbarium, a number which is quite small if compared to those of several others European countries, for example, up to 2 million records for the UK.
In the framework of project "Dryades" (Nimis et al. 2003), an effort to aggregate data from Italian lichen collections is being carried out, aiming at making data available online on ITALIC, the information system on Italian lichens (Nimis 2022).At the same time, records will be encoded in the Darwin Core standard (Wieczorek et al. 2012) and will be shared in the GBIF.In Italy, there are several important historical collections, mostly dating back to the "Golden Period" of Italian Lichenology in the second half of the 19 century ( Nimis 2018), such as the herbaria of A.B. Massalongo (VER), F. Baglietto (MOD), M. Anzi (TO) and A. Jatta (NAP) (Tretiach and Valcuvia Passadore 1990).While efforts for their digitisation are foreseen, they will provide serious challenges, both as far as nomenclature th and the georeferencing of localities are concerned.The latter is an especially challenging task, since localities are reported with obsolete toponyms or not reported at all.Thus, we prioritised 13 modern herbaria (with specimens collected after 1950): CLU, FI, GDOR, GE, HLUC, ORO, SI, TO, TSB and the private herbaria of G. Gheza, J. Nascimbene, S. Ravera and W. von Brackel.The digitisation and publication of the TSB lichen collection is, thus, the first step towards making all the data from Italian lichen collections publicly available.

Description:
The Italian collection of the TSB lichen herbarium hosts specimens collected from all the 20 administrative regions of Italy.
Sampling description: Specimens were mostly gathered in the course of field surveys devoted to the exploration of different areas of the country, where both common and rare species were collected.All specimens are stored in 15 cm x 10 cm paper envelopes.Label data were digitalised and stored in a MySQL database, which has been made publicly available on ITALIC, the information system on Italian lichens (Nimis 2022) and on GBIF (Martellos et al. 2022).
Quality control: Specimens were collected and identified by experienced lichenologists (mostly by Nimis PL, Tretiach M and Muggia L), and sometimes revised by foreign specialists.Scientific names have been automatically aligned to the latest checklist of Italian lichens (Nimis 2016) by means of a customised version of the FlorItaly name matching tool (Conti et al. 2021).The verbatim scientific name, i.e. the name originally written on the label, has been retained together with the currently accepted name.Since for almost all specimens geographical coordinates of the collection locality were missing, all specimens were georeferenced a posteriori using Google Maps, Google Earth and regional GIS maps.The georeferencing process followed the best practices by Chapman and Wieczorek (2020).Taxa and specimens numbers for each kingdom, phylum, class, order, family and genus are available in a spreadsheet (Suppl.material 1) and can be graphically visualised as a krona graph (Fig. 2; the interactive file is provided in Suppl.material 2).

Temporal coverage
Notes: Specimens have been collected and recorded from 1810 to 2021.Occurrences per year are shown in Fig. 3.All specimens dated before 1984, the year in which the TSB collection was started, come from exsiccata collections or from exchanges with other Herbaria.The highest number of accessions was between 1987 and 2010, corresponding to the peak of lichenological exploration of Italy by researchers of the University of Trieste.The Italian lichens dataset from the TSB herbarium (University of Trieste)