After the publication of Volume IV in 1997, the introduction of molecular methods into ecology led to significant new findings. Emphasizing these advances, the chapters for the second edition have been completely updated and revised. This volume provides insight into current research on fungal populations and communities. It focuses on fungal responses to the physical environment, interactions with other fungi, microorganisms and invertebrates, the role of fungi in ecosystem processes such as decomposition and nutrient cycling, and aspects of biogeography and conservation. Several chapters deal with various applications in, e.g. biological pest control, natural products discovery, and the degradation of toxic organic compounds. This is an invaluable source of information both for scientists who wish to update their knowledge of current progress and for graduate students interested in obtaining a first overview of this field of research.