PNNL

Abstract

Microbial communities play important roles in soil health, contributing to processes such as turnover of organic matter and nutrient cycling. As soil edaphic properties such as chemical composition and physical structure change from surface layers to deeper ones, the soil microbiome similarly exhibits substantial variability with depth, with respect to both community composition and functional profiles. However, soil microbiome studies often neglect deeper soils, instead focusing on the top layer of soil. Here we provide a synthesis on how the soil and its resident microbiome change with depth. We touch upon soil physicochemical properties, microbial di-versity, composition, and functional profiles, with a special emphasis on carbon cycling. In doing so, we seek to highlight the importance of incorporating analyses of deeper soils in soil studies..