Riparian management

Fine sediment: a major disruptor of habitat connectivity and food-webs in streams

As part of his PhD research, Frank Burdon aims to better understand how impacts of human disturbance propagate through groundwater, stream, and riparian food-webs.

Land management practices associated with plantation forestry, agriculture and urbanisation have contributed to the increased flow of sediments into aquatic habitats. Demands on land has caused the removal of stabilizing vegetation and riparian buffers, altered wetland habitats, and has increased the area of impervious surfaces covering the land. As a result of these activities, sediment runoff into streams, rivers, lakes, and estuaries has increased and is adversely affecting the biodiversity and ecology of these areas.

Despite the burgeoning literature describing the lateral linkages of cross-habitat subsidies between stream and riparian food-webs, few studies have investigated the importance of the vertical dimension in stream ecosystems. Stream ecosystems depend on the movement of water, detritus, nutrients, and organisms between groundwater and the benthic habitat. The deposition of sediment can change the physical structure of the streambed and impair the vertical exchange with the hyporheic zone.

Fine sediment deposition and colmation of the streambed may negatively affect the benthic and riparian communities of stream ecosystems by decoupling the linkages with the hyporheic and groundwater habitats. The hyporheos can be an important habitat for stream insects but the paucity of studies investigating food-web linkages between the streambed and the hyporheic zone means that these interactions are still poorly understood.

People involved in this project

Frank Burdon (PhD student)
Jon Harding
Angus McIntosh
Jon O'Brien