Location: Soil Drainage ResearchTitle: Implications of the results of colonization experiments for designing riparian restoration projects adjacent to agricultural headwater streams Author
|Smiley, Peter - Rocky|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/10/2014
Publication Date: N/A
Citation: N/A Interpretive Summary:
Technical Abstract: Many headwater streams and their riparian habitats in the Midwestern United States have been modified for agricultural drainage. Agricultural drainage often results in reductions of physical habitat diversity, shifts from woody to herbaceous riparian vegetation, and the loss of riparian habitat. The effects of these riparian habitat modifications have been widely documented for instream macroinvertebrates, but less is known about how changes to riparian vegetation influences aquatic macroinvertebrates within the riparian zones of agricultural headwater streams. Our objective is to highlight how the results of colonization experiments can provide science-based information that can be applied towards restoring riparian zones of agricultural headwater streams. Colonization experiments involve the placement of water-filled mesocosms lacking nutrients, organic matter, and aquatic macroinvertebrates into the environment and documenting changes in habitat and aquatic macroinvertebrates throughout the experiment. We conducted two colonization experiments adjacent to agricultural headwater streams in central Ohio in the summer of 2009 and 2013 to determine if aquatic macroinvertebrate colonization differed among riparian zone types (i.e., unplanted herbaceous riparian zones, planted herbaceous riparian zones, forested riparian zones) present within seven agricultural headwater streams. Physical habitat, water chemistry, and/or aquatic macroinvertebrates were sampled from July to August 2009 and June to August 2013. Our 2009 experiment found that aquatic macroinvertebrate diversity and zooplankton relative abundance was greater in forested riparian zones having greater canopy cover than herbaceous riparian zones. Preliminary results from our 2013 experiment indicated that mesocosms within forested riparian zones with greater canopy cover exhibited lesser mean water temperatures than those within herbaceous riparian zones with reduced canopy cover. Results from our colonization experiments suggest that restoration projects that lead to increases in riparian width and increases in the amount of riparian woody vegetation adjacent to agricultural headwater streams will benefit aquatic macroinvertebrates living within these riparian zones.