Fungal Diversity: Global Perspective and Ecosystem Dynamics

All major biomes on earth contain a multitude of microorganisms; of this, a considerable proportion is shared by fungi in terms of abundance, genetic diversity, biomass and total biospheric DNA. In various ecosystems, fungi exist as pathogens, mutualists and decomposers and are of considerable ecological value as they influence nearly every component of the ecosystem services, viz. protection against pathogens, homeostatic balance, decomposition and other functions. Fungi are, however, functionally redundant in some ecosystems and endemic to certain bioregions. Next-generation sequencing has now uncovered unculturable fungal forms that has transformed our understanding towards their role in unexplored environments; cataloguing their diversity and study of their biogeographical patterns at local and global scale have become simpler. The data generated through advanced molecular approaches have introduced the concept of ‘mycobiome’ which was largely overlooked or considered as an integral yet small component of the ‘microbiome’ until now. In this chapter, we report new information that reveals various deterministic factors that shape fungal communities and their probable role in maintaining human, soil and plant health. Finally, we also discuss how the view of mycobiome has taken an independent shape and has more recently helped understand interkingdom interactions.