Yeasts are prevalent in most habitats on Earth, where they often reach high
abundance and establish species-rich communities. To date, most research efforts have
focused on cataloging the prevalence and diversity (at the phylogenetic and/or
physiological level) of yeasts in different habitats and searching for reservoirs of novel
yeast taxa. However, little is known regarding the ecological roles that yeasts play in
their natural habitats or the relationships that they maintain with other coexisting
organisms. This chapter provides a general overview of yeast habitats, with attention to
the response of yeasts to diverse abiotic and biotic factors. Furthermore, the chapter
presents a detailed description of some relevant systems where yeasts interact with
other macro- and microorganisms, namely the insect microbiome, phylloplane,
decaying cactus tissues, angiosperm flowers, human microbiome, and industrial
processes. Future challenges in the study of yeast ecology are briefly discussed.
Keywords: Anthropogenic environment, Aquatic habitat, Atmosphere, Cactus, Community, Dispersal, Diversity, Ecology, Environmental factor, Evolution, Floral nectar, Flower, Human mycobiome, Industrial process, Insect microbiome, Multipartite interaction, Phylloplane, Soil, Symbiosis, Yeast.