LAUSR

The study of plant root systems is not new (Darwin and Darwin, 1880), but it has received increased attention in recent decades with technological advancements in molecular genetics (Cooper and Rao, 2006) and efforts to standardize procedures (e.g., root sampling methods based on anatomy, morphology, and physiology) in field ecology (Freschet and Roumet, 2017). Plant root systems play an integral role in numerous ecological processes, for example, from building soil structure (Rillig et al., 2015), to impacting species composition (Craine and Dybzinski, 2013), as well as mediating carbon and nutrient cycling within ecosystems (Bardgett et al., 2014). Specifically, roots account for up to 63% of the plant’s total biomass (Poorter et al., 2012) and up to 60% of net primary productivity in many ecosystems (McCormack et al., 2015). Despite their ecological importance, our understanding of plant root systems and their interactions with other plants, microbes, and the environment is often limited due to methodological challenges associated with their hidden nature in the soil matrix. In this special issue of Applications in Plant Sciences, “Methods in Belowground Botany,” we present six papers that explore current methods and challenges in investigating plant root systems, ranging from the subcellular to the ecosystem level, with a wide variety of applications that advance our understanding of belowground botany.