Understanding how ecological processes result from changing biodiversity first requires strong frameworks to detect and quantify these changes. As ecosystems change in ever-more rapid ways, ecologists grapple with evolving perspectives and methods that depart from previous ideas of ecological stability. Seemingly simple questions such as “when has a community changed?” pose challenges because of the lack of clear thresholds in many gradual temporal processes. Similarly, cross-discipline differences in perspectives on what defines a community – whether a community is a phenomenalistic occurrence or the outcome of biotic interactions – have resulted in largely compartmentalized development of community theory and related quantitative methods. A suite of emerging methods promises to overcome some of these challenges by providing conceptual and analytic tools to examine community change holistically in suites of co-occurring, interacting, yet still independent species. This symposium will focus on novel analytical approaches and quantitative models that bridge gaps among ecologists trying to study biodiversity change. By highlighting a diversity of perspectives – experimental versus observational, methodological versus empirical, predictive versus paleoecological – the ultimate goal is to highlight new directions in community ecology that are emerging from across the ecological discipline in order to meet the challenge of understanding rapid biodiversity change. Diverse views and approaches for dealing with biotic interactions, measuring change, scaling communities, and defining biodiversity, are some of the themes we expect to emerge from this symposium. Synthetically, this symposium aims to clarify emerging concepts of communities in the Anthropocene – and to provide us with the tools to study them.