The Hawksworth (1991) estimate was established based on a ratio of plant:fungal species in temperate regions. Whether these ratios hold up in tropical buy BIBW2992 regions is indirectly assessed in the papers of Berndt (2012) and Mangelsdorff et al. (2012) with sometimes conflicting results, highlighting the value of both sound taxonomic and monographic treatments as well as the need for more long-term fungal check details studies in tropical regions. For instance, the rust fungi (obligate plant pathogens) may be the best documented group of microfungi, yet Berndt (2012) found that ratios of known rust:plant

species in Neotropical countries ranged from 1:16 to 1:124—no doubt a reflection, at least in part, of under sampling for fungi in most of these areas. Lücking (2012) asks the question of not just how many species remain to be discovered, but of what form these species may take. He uses a novel ‘character correlation index’ whereby combinations of traits that are known to be correlated in currently described species are used to predict the traits that Idasanutlin chemical structure are expected to be correlated and found in currently unknown species. He predicts that another 48 lichen-forming fungi in the Graphis group alone remain to be discovered, approximately doubling the

known number in this genus. The impacts of disturbances on fungal communities have been poorly studied in tropical regions, perhaps because these communities have been considered, likely wrongly, as both resistant and resilient to disturbance (Allison and Martiny 2008). Three papers in this issue address Cepharanthine this assumption: da Silva et al. (2012) determine the impact of mining and restoration in Brazilian restinga on communities of arbuscular mycorrhizal fungi by counting and identifying spores. Hattori et al. (2012) show how diversity of polypore fungi is

dependent upon the presence of suitable host trees that may be removed by logging or conversion to plantations in their Malaysian study sites. And, as already discussed, López-Quintero et al. (2012) examine the effects of clearance for shifting cultivation and subsequent forest recovery on fungal diversity. Just as the study of Berndt (2012) shows that species data is unevenly distributed geographically, other papers in this issue show that there are, likewise, a number of specialized habitats that still remain to be fully assessed for tropical fungal diversity. These include fungi inhabiting insect guts, among which are Trichomycetes that have been reviewed by Lichtwardt (2012). The abundance and diversity of insect host species will clearly affect fungal species diversity and an improved assessment of insect-associated fungal diversity in the tropics is certainly a priority for mycologists. Finally, Jones and Pang (2012) provide a timely review of tropical aquatic fungi, highlighting areas in need of future research.