How diverse is the lichenized fungal familyTrypetheliaceae(Ascomycota: Dothideomycetes)? A quantitative prediction of global species richness

Abstract

A quantitative prediction of global species richness in the lichenized family Trypetheliaceae employing a grid method previously used in similar approaches for the family Graphidaceae and the genus Cora (Hygrophoraceae) is provided. 421 currently known taxa were used as a base for the calculation and we predict a total of nearly 800 species, corresponding to an increase of almost 100%. Most of the unrecognized taxa are predicted to occur in the Neotropics, which have the highest known species richness. The Palaeotropics are less diverse. In contrast to Graphidaceae, which are mostly confined to rainforests, Trypetheliaceae show substantial species richness in dry forest and savannah ecosystems, and future collection efforts should take well-preserved areas representing such ecosystems into consideration.

A revisionary synopsis of theTrypetheliaceae(Ascomycota:Trypetheliales)

“…However, there is still a high proportion of species known only from their type material. This also strongly suggests that many species still remain undiscovered, as shown by a statistical prediction exercise (Aptroot et al 2016c). This is corroborated by the fact that a few short field trips in small areas in Brazil yielded many undescribed species (Aptroot & Cáceres 2016;Aptroot et al 2016b;Lücking et al 2016a), and also taxonomic inventories of other understudied areas, such as Panama and Bolivia, unravelled numerous novel taxa Lücking et al 2016b).…”

“…Rather, we present this revisionary synopsis to stimulate further research in this highly diverse and fascinating family, hoping that future workers will pay more attention to morphological, anatomical and chemical features to identify species and that the molecular phylogenetic data will be much expanded. Undoubtedly, further research will lead to additional changes in the classification of Trypetheliaceae and many additional new species will be discovered (Aptroot et al 2016c). Notably, we are more confident with the taxonomic concept of the less common and rare species, which often have a unique combination of diagnostic characters different from similar and related taxa, than with the common species, such as Astrothelium aeneum, A. bicolor, A. porosum, A. phlyctaena, A. scoria and Trypethelium eluteriae which have a degree of variation that needs to be assessed by additional molecular phylogenetic studies.…”

“…A table with the currently accepted species and their updated, confirmed world distribution is available as supplementary material in Aptroot et al (2016c).…”

Current Insight into Traditional and Modern Methods in Fungal Diversity Estimates

“…In addition to estimating the total number of fungi, the global biodiversity of fungi has been extensively investigated for predicting their accurate estimate on earth. The number of advanced techniques, along with the number of numerical analytical methods, enabled researchers not only to identify and describe those fungi which are either not described, incorrectlyidentified or described incompletely, but also in understanding plant: fungus ratios [ 12 , 99 ], quantitative macroecological grid-based approaches [ 115 , 116 , 117 ], ecological scaling laws and methods based on environmental sequence data including plant: fungus ratios [ 10 , 113 ]. These studies on estimates proved fungi to be one of the largest groups of living organisms on this planet.…”

Two new species of Astrothelium from Sud Yungas in Bolivia and the first discovery of vegetative propagules in the family Trypetheliaceae (lichen-forming Dothideomycetes, Ascomycota)

“… Trypetheliaceae Zenker is the core family of the order Trypetheliales Lücking, Aptroot & Sipman and comprises about 500 species and 19 genera ( Lücking et al 2017 ; Wijayawardene et al 2022 ); however, according to Aptroot et al (2016a) , the species diversity is higher. It is predicted that the total number of species is close to 800, with the majority of unrecognised taxa to be found in the Neotropics ( Aptroot et al 2016a ). Nevertheless, with about 500 species already known, Trypetheliaceae is one of the three, together with Graphidaceae Dumort.…”