River networks play a fundamental role in shaping Earth’s surface—sculpting landscapes, routing water, sediment, and nutrients across continents, and sustaining critical aquatic habitats. They also influence the distribution and evolution of terrestrial and aquatic species, acting as both barriers and dispersal corridors. Crucially, these networks are dynamic: they reorganize over timescales from decades to millions of years through processes such as drainage divide migration, river capture, and avulsion. These reorganizations can produce erosive pulses and alter fluvial connectivity, driving both geomorphic change and biological diversification. However, the fundamental controls on these reorganization modes, their relative importance, and the interplay between external and autogenic drivers remain open questions.This session invites contributions that examine the mechanisms, rates, and impacts of drainage network reorganization. We encourage studies that investigate how these changes influence landscape evolution and biodiversity.  Approaches may include field observations, geochronology, numerical and analog modeling, molecular datasets, phylogenomics, and biogeography.

• B - Biogeosciences