Nearly 100 years have passed since Beijerinck’s statement framing the spatial distribution of microorganisms: “Everything is everywhere; the environment selects”. Since then, technological advances have dramatically increased our ability to probe biological organisms' identity, function, and dynamics at both ever smaller and ever larger scales. Yet our understanding of the relationship between molecular microbiology, the spatial and temporal distribution of microbial community assembly, and the influence of these on regional- and global–scale environmental processes remain coarse at best. We have not yet effectively managed to bridge our understanding of microbial processes across scales. Major biogeochemical cycles are governed by microbial activity that, in turn, exerts its influence on its surroundings. However, the heterogeneity, complexity, and temporal scale of these feedbacks have made rigorous inquiry difficult. The aim of this session is to identify the technical and conceptual gaps in understanding the ramifications of microbial properties and processes in the environment. Our central question asks: How can existing technologies at the molecular scale (e.g. environmental metagenomics, metabolomics) and the global scale (remote-sensing) productively be merged in order to gain further insight into how the organization of microbial assemblages affects ecosystem processes? Our speakers will cover current aspects of the interplay between microbes and the environment, in both marine and terrestrial systems. The session will begin by contextualizing the recent technological advances, which have dramatically changed our ability to understand processes at both the molecular and the landscape scale. We are particularly interested in the recent understandings gained from environmental microbial metagenomics and related techniques. The session will next explore how these have been linked in research that spans the divide between microbial and ecosystem ecology, first in marine and then in terrestrial systems. The session will then conclude with the presentation of research that approaches microbial processes from the perspective of remote sensing and large-scale modeling. By bringing together researchers who are thinking about microbial process and effect across systems and across scales, we hope to begin the process of introducing mechanism into the everpresent 'black boxes' used currently to capture our (at present largely empirical) understanding of microbial dynamics. The charge is not an easy one, but given the critical role microorganisms play in every environment on Earth, it is one that we must begin to tackle.