One hundred and seventy-five new species of Graphidaceae: closing the gap or a drop in the bucket?

Abstract

Recent studies of the global diversity of the lichenized fungal family Graphidaceae suggest that there are a large number of species remaining to be discovered. No less than 640 species have been described since 2002, including 175 new species introduced in a collaborative global effort in a single issue in this journal. These findings suggest that the largest family of tropical crustose lichens may have an even higher number of species than Parmeliaceae. To estimate whether the discovery of 175 new species is a significant step forward in cataloguing extant diversity in this family, we employed a parametric method to predict global species richness of Graphidaceae using a GIS-based grid map approach. The model employs linear regression between observed species richness and sample score and vegetation composition per grid to predict individual grid species richness, and interpolation of species grid distributions to predict global species richness. We also applied a non-parametric species-area curve approach and non-parametric species richness estimators (Chao, Jackknife, Bootstrap) to compare the results from the different methods. Our approach resulted in a prediction of 4,330 species of Graphidaceae, including approximately 3,500 (sub-)tropical species in the core subfamilies Fissurinoideae, Graphidoideae, Redonographoideae, plus 125 species restricted to extratropical regions (outside the zone between 30° northern and 30° southern latitude) and 700 species in subfamily Gomphilloideae. Currently, nearly 2,500 species are known in the family, including species not yet formally described. Thus, our model suggests that even after describing 175 species in this issue and with another approximately 140 awaiting publication, the number of species still to be discovered and described is more than 1,800, and much work remains to be done to close this substantial gap. Based on our approach, we predict that most of this undiscovered diversity is to be found in Mexico, the northern Andean region, the eastern Amazon and central and southern Brazil, tropical West Africa, continental Southeast Asia, Indonesia, and Papua New Guinea.

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

“…Since Graphidaceae is considerably larger, however, the impact on the absolute number of expected taxonomic novelties is smaller in Trypetheliaceae. Similarly, maximum predicted grid values are much lower for Trypetheliaceae (little over 200 species) than for Graphidaceae (close to 600 species per grid; Lücking et al 2014a). As in the prediction for Graphidaceae, the individual grid estimates are not to be considered accurate in this case, since the linear correlation applies a smoothing effect on the model (Lücking et al 2014a).…”

“…In Graphidaceae, vegetation types that contribute uniquely and substantially to overall species richness are the rainforest and rainforest mountain divisions and the savannah and savannah mountain divisions where they are found mainly in the rainforest canopy (Lücking et al 2014a). In Trypetheliaceae, the latter two divisions also provide unique taxa, such as in the genera Bogoriella and Polymeridium (Aptroot et al 2013a).…”

“…In Trypetheliaceae, the latter two divisions also provide unique taxa, such as in the genera Bogoriella and Polymeridium (Aptroot et al 2013a). Accordingly, we used a slightly different relative scaling of vegetation scores for Trypetheliaceae, with increased scores for the savannah division ( Lücking et al (2014a), sampling, vegetation, remote and region scores were subsequently combined into a total prediction score for each grid by simple multiplication (Table 1).…”

Three new species of Krogia (Ramalinaceae, lichenised Ascomycota) from the Paleotropics

“…Aptroot et al 2018; Lücking et al 2014; Masson et al 2015; Naksuwankul et al 2016; Sodamuk et al 2017). It seems that the full diversity of tropical lichens is yet to be discovered.…”

ONE HUNDRED AND SEVENTY FIVE NEW SPECIES OF GRAPHIDACEAE—a special issue of Phytotaxa

“…Ferraro et al 2014;Peláez et al 2014;Sipman 2014). With these contributions, we increase the number of known species in the core group of the family (excluding subfamily Gomphilloideae) by almost 10% in a single issue.…”