How to know the fungi: combining field inventories and DNA‐barcoding to document fungal diversity

The fungi kingdom is among the most diverse eukaryotic lineages on Earth with estimates of several million extant species (O´Brien et al., 2005; Blackwell, 2011; Taylor et al., 2014). Fungi play critical roles in carbon and nutrient cycling of terrestrial and aquatic ecosystems, and they are important pathogens and mutualists (Read & Perez-Moreno, 2003; Taylor et al., 2012; Grossart et al., 2016). More than 80% of plant species form symbioses with fungi and these symbioses have been crucial to the colonization of terrestrial ecosystems (Field et al., 2015a; Selosse et al., 2015). Despite their impacts on primary ecosystem functions, assessments of fungal biodiversity estimate that only c. 10% of fungal species have been described (Bass & Richards, 2011; Hibbett et al., 2011).