A community has a diverse suite of definitions, as many as there are scientific fields and sociological units. Among humans, there is a place-based variant such as a city defined by political boundaries, or an interest-based variant focused on a group of people defined by their interactions. The same issues plague the field of community ecology, especially when we address a topic such as a mycorrhiza, which is a functional relationship. Early measurements of communities looked for spatial boundaries, the edge of a meadow; a shift in forest type with a physical edge such as a shift in topography; an obvious shift in plant types such as a forest edge. Theophrastus (~44 BCE) noted that most mushrooms were found in forests (which included EM species) but not grasslands (which were almost exclusively AM). Alexander von Humbolt drove some of the earliest developments in community and ecosystem ecology by showing relationships between climate and vegetation both up elevation gradients, such as his beautiful and accurate 1807 Tableau Physique, drawings of vegetation up Mount Chimborazo in Ecuador, and his Geographical Distribution of Plants – climate consortia of plants – in relation to global climate patterns (371).