Seed dispersal experiment this summer

Our postdocs Xiaolei Su & Lovisa Lind conducted a seed dispersal experiment this summer, and now they’ve completed surveys of the channel geometry. Boreal streams are complex and dynamic systems, characterized by different process domains: rapids, slow flowing reaches and lakes. Plant communities usually differ between these domains. We hypothesize that this is probably caused by differences in their instream propagule dispersal patterns. To test this hypothesis, we released wooden cubes in all three types of domains during the spring flood in the Hjuksån catchment, a tributary of the Vindel River in northern Sweden. To determine which set of environmental factors governing the dispersal patterns, we surveyed wind speed/direction, surface flow velocity and geomorphic channel characteristics of the process domains.

Seed mimics stranded in backwater along rapid section

Seed mimics stranded in backwater along rapid section

Xiaolei records cub locations

Xiaolei records cub locations

Lovisa recollecting dispersed seed mimics

Lovisa recollecting dispersed seed mimics

 

BioRest Workshop

The BioRest research group had a 3-day workshop in Örnsköldsvik, March15-17, 2017. We discussed research results about the recovery of macroinvertebrates and riparian vegetation after restoration, and are planning more field work looking at how riparian vegetation differs based on different stream types (process domains) throughout the stream network.WebpagePic_20170317

Conference: Society for Freshwater Science

Francesca will attend the annual meeting of the Society for Freshwater Science that will be held in Sacramento, 21-26 May. This is one of the most important conferences worldwide in the field of freshwater science- it includes ca. 50 sessions encompassing cutting-edge research in the field.  Francesca will give a talk entitled “Restoring stream physical heterogeneity: effects on benthic macroinvertebrates”, which will showcase the first results from her research on the recovery of aquatic macroinvertebrates after stream restoration.

Flume Experiment

In the summer of 2015, Lina was at the Engineering Research Center at Colorado State University, Colorodo, USA, conducting a flume experiment to model semi-alluvial streams. A flume is a small model of a stream that can be used to conduct experiments on streams to see what happens if we change the slope, the water flows, or sediment size. A flume is also beneficial when we want to see how a channel forms over a long period of time. Lina modeled a typical semi-alluvial stream in northern Sweden with large boulders, cobbles, and gravel and relatively low slopes (2 & 5%) for such coarse sediment.

Looking upstream at bankfull flow

Flume2

Bird’s eye view of the flume with low flows. Note the coarse sediment, representing boulders and cobbles