Ectomycorrhizal symbiosis plays a major role in biodiversity and stability of ecosystems in tropical forests. It is a research imperative in tropical and neotropical forest ecosystems because they contain ecologically and economically important tree species. This book provides an overview of the knowledge of ECM symbioses in tropical and neotropical ecosystem forests. The contents address diversity and function of ectomycorrhiza associated with forest plants, impacts of ectomycorrhiza on plant diversity and composition, regeneration and dynamics of ecosystems, biomass production in forestry, and adaptation of ectomycorrhiza.