Introduction

Fungi are a group of organisms that cannot fix energy and nutrients directly (but see Tugay et al., 2006; Dadachova et al., 2007; Dadachova and Casadevall, 2008), so they use the energy stored in plant and animal biomass to create their own growth. Fungi are a key group of organisms that interact with other organisms and the abiotic environment to regulate ecosystem processes. In his introductory chapter to The Fungal Community: Its Organization and Role in the Ecosystem (Carroll and Wicklow, 1992), Alan Rayner speaks of the importance of fungi in ecosystems in the following four major functions: (1) As decomposers, fungi drive the global carbon cycle. (2) As mycorrhizal symbionts, they form absorptive accessories to roots, linking the activities of separate plants and underpinning primary production in forests, heathlands, and grasslands. (3) In lichens, they clothe what might otherwise be bare parts of the planet. (4) As parasites, they regulate population dynamics of their hosts.