Data from: Alpha and beta diversity of connected benthic–subsurface invertebrate communities respond to drying in dynamic river ecosystems

Drying disturbances are the primary determinant of aquatic community
biodiversity in dynamic river ecosystems. Research exploring how
communities respond to disturbance has focused on benthic invertebrates in
surface sediments, inadequately representing a connected community that
extends into the subsurface. We compared subsurface and benthic
invertebrate responses to drying, to identify common and context-dependent
spatial patterns. We characterized community composition, alpha diversity
and beta diversity across a gradient of drying duration. Subsurface
communities responded to drying, but these responses were typically less
pronounced than those of benthic communities. Despite compositional
changes and in contrast to reductions in benthic alpha diversity, the
alpha diversity of subsurface communities remained stable except at long
drying durations. Some primarily benthic taxa were among those whose
subsurface frequency and abundance responded positively to drying.
Collectively, changing composition, stable richness and taxon-specific
increases in occurrence provide evidence that subsurface sediments can
support persistence of invertebrate communities during drying
disturbances. Beta-diversity patterns varied and no consistent patterns
distinguished the total diversity, turnover or nestedness of subsurface
compared to benthic communities. In response to increasing drying
duration, beta diversity increased or remained stable for benthic
communities, but remained stable or decreased for subsurface communities,
likely reflecting contrasts in the influence of mass effects, priority
effects and environmental filtering. Dissimilarity between subsurface and
benthic communities remained stable or increased with drying duration,
suggesting that subsurface communities maintain distinct biodiversity
value while also supporting temporary influxes of benthic taxa during
drying events. As temporary rivers increase in extent due to global
change, we highlight that recognizing the connected communities that
extend into the subsurface sediments can enable holistic understanding of
ecological responses to drying, the key determinant of biodiversity in
these dynamic ecosystems.