MULTIDIMENSIONAL METACOMMUNITIES

Metacommunity dynamics are increasingly recognized within freshwater research. Linking to our interests in biodiversity at local to global scales, we seek to balance increasing understanding of metacommunity dynamics in horizontal dimensions (i.e. longitudinal, from upstream to downstream, and lateral, from the channel into the surrounding catchment) by recognizing vertical connectivity between surface and subsurface sediments. We characterize responses of the benthic and hyporheic contributors to connected metacommunities to longitudinal environmental gradients, and in particular drying intensity in temporary streams. By better characterizing communities in the vertical dimension, we seek to inform management activities that promote benthic-hyporheic connectivity. We focus on macroinvertebrates: a diverse and abundant aquatic biota that enables us to effectively address our research questions:

​

• How do different aquatic habitats interact in the landscape: do metacommunities change between flowing, ponded and dry phases, and what mechanisms drive observed changes?

• Do benthic and hyporheic communities show comparable or contrasting responses to environmental changes?

• Do the hyporheic sediments act as an ecological refuge for primarily benthic taxa following the loss of surface water in temporary streams, and in what circumstances?

• Do benthic and hyporheic community responses to drying differ depending on disturbance magnitude?