Differential roles of deterministic and stochastic processes in structuring soil bacterial ecotypes across terrestrial ecosystems

Soil bacteria are vital to ecosystem resilience and resistance, yet ecological attributes and the drivers governing their composition and distribution, especially for taxa varying in ecological traits and inhabiting different ecosystems, are not fully understood. Here, we analyzed a large-scale bacterial community and environmental dataset of 622 soil samples systematically collected by us from six major terrestrial ecosystems across the United States. We show that soil bacterial diversity and composition significantly differ among ecotypes and ecosystems, partially determined by a few universal abiotic factors (e.g., soil pH, calcium, and aluminum) and several ecotype- or ecosystem-specific ecological…