ARS | Publication request: Influence of Riparian Habitat and Nutrients on Aquatic Communities Within Riparian Zones of Headwater Streams

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 13, 2010
Publication Date: April 14, 2010
Citation: Seger, K., Smiley, P.C. 2010. Influence of Riparian Habitat and Nutrients on Aquatic Communities Within Riparian Zones of Headwater Streams. Meeting Abstract. p. 7.

Technical Abstract: Headwater streams are the smallest streams in a watershed. Their small size and high frequency of occurrence make them susceptible to anthropogenic habitat alterations. Many headwater streams in the Midwestern United States have been channelized to drain agricultural fields. Aquatic macroinvertebrate communities are an important biological component of riparian zones of headwater streams. Previous studies have evaluated how aquatic community colonization differs between habitat types and the influence of specific habitat variables on aquatic community colonization. However, previous studies have not examined aquatic community colonization within the riparian zones of headwater streams or the influence of stream channelization. I addressed the following research questions: 1) Does canopy cover, water depths, and water chemistry within experimental mesocosms differ between riparian zones of channelized and unchannelized headwater streams? and 2) Does aquatic macroinvertebrate colonization within experimental mesocosms differ between riparian zones of channelized and unchannelized headwater streams? Experimental mesocosms with deionized tapwater were placed within the riparian zones of two channelized and two unchannelized streams in central Ohio in July 2009. Over a course of 45 days, I sampled aquatic macroinvertebrates and measured canopy cover, water depths, and water chemistry from the experimental mesocosms. Canopy cover, turbidity, and water depths were greater in the riparian zones of unchannelized streams than channelized streams. Dissolved oxygen was greater in the riparian zones of channelized streams than unchannelized streams. Turbidity, dissolved oxygen, and nutrients increased from the beginning to the end of the study. Macroinvertebrate abundance, taxa richness, and relative abundance of mosquitoes, copepods, cladocerans, and dipterans were greater in the riparian zones of unchannelized streams than channelized streams. Temporal trends of zooplankton relative abundance and the Shannon diversity index differed between riparian habitat types. Additionally, macroinvertebrate abundance, richness, and relative abundance of mosquitoes, copepods, and dipterans increased from the beginning of the experiment to the end. My results indicate that aquatic community colonization in the riparian zones of headwater streams is influenced by both riparian habitat type and nutrients. My results also suggest that stream channelization reduces aquatic community diversity and abundance within the riparian zones of headwater streams in central Ohio.