Oligotrophic (nutrient-poor) soil ecosystems have been found to contain a wide diversity of bacterial communities. These communities vary in composition according to the mineral content and the chemical and physical properties of their environment. This creates a challenge for microbiologists to identify population patterns based on ecosystem characteristics. Advances in new technologies, and in particular high-throughput DNA sequencing, have improved the identification of bacterial groups, thus aiding our understanding concerning the presence and role of microbial populations in different biomes. Here, we review the principal bacterial members on the surface layers of nutrient-poor soil ecosystems, as well as the bacterial groups present in various oligotrophic ecosystems. We also assess factors that may shape the bacterial communities in these ecosystems such as their involvement in mineral transformations in order to better understand their distribution and possible functions on oligotrophic soil surfaces.