Climate and anthropogenic activities regulate genome-inferred bacterial growth potential

This is the authors' abstract. We don't add key points for this paper.

Community-level growth potential is a central bacterial life-history trait, yet its environmental controls and responses to land use remain uncertain at continental scales. Here, we analysed 264 topsoil metagenomes across Australia to test how climatic factors, edaphic habitat and land use shape bacterial growth potential. Genome-inferred growth potential showed a clear spatial pattern, increasing towards higher latitude. At the environmental level, aridity index emerged as the primary predictor, with a distinct transition near the dryland threshold (aridity index ≈ 0.34). Consistently, the stress–resource habitat analysis showed that water stress, rather than resource availability, was the primary constraint on growth potential. Beyond these environmental effects, agricultural land use was associated with an average 6.1% reduction in growth potential across habitats. These findings show that climate sets the broad-scale distribution of bacterial growth potential, habitat conditions modify its environmental controls, and agricultural land use reduces growth potential. This framework improves our understanding of how bacterial life-history strategies are organised across environmental gradients and land-use change.