Abstract
Temporary rivers (TRs) dominate global river networks and are
increasing in occurrence and spatiotemporal extent. However, few
studies have investigated the communities that establish after
rewetting events (i.e. the end of the dry phase), when local
hydrological conditions can shape the communities through species
sorting, and the spatial connectivity of sites can also influence
colonisation. Here, we analysed the relative importance of both local
hydrological conditions and spatial connectivity on the invertebrate
communities of seven not impacted Mediterranean TRs after rewetting.
We quantified the frequency and duration of drying events and the time
since flow resumed. We also quantified spatial connectivity based on
each site’s position in the river network (i.e. network connectivity)
and the presence of nearby disconnected streams. Overall, we found
that both hydrological conditions and network connectivity played a
significant role in structuring aquatic invertebrate communities after
rewetting. Taxonomic richness, functional richness and functional
redundancy decreased with the frequency and duration of drying events
and increased with time since the most recent rewetting. Network
connectivity showed a significant unimodal relationship with taxonomic
and functional metrics. In contrast, the presence of nearby
disconnected streams was negatively related to functional richness and
functional dispersion. Given that flow intermittence in Mediterranean
areas is expected to intensify under future global change scenarios,
our results can be helpful to guide future conservation and management
actions.