Date of Graduation

Spring 2020

Degree

Master of Science in Biology

Department

Biology

Committee Chair

Debra Finn

Keywords

Odonata, springs, bioindicators, riparian zones, Ozark Highlands, stream bioassessment

Subject Categories

Biology | Entomology | Terrestrial and Aquatic Ecology

Abstract

The Odonata (dragonflies and damselflies) are often ineffectively sampled during standard stream bioassessments in North America. Subsequently, odonates are not frequently regarded as informative taxa for stream assessment, particularly when monitoring the ecological impacts of organic pollution. I hypothesized that stream-dwelling odonates should be more useful bioindicators for the assessment of riparian conditions surrounding streams because vegetation associated with streams is used for oviposition, roosting and to establish breeding territories. I selected twelve Ozark spring streams that satisfied a broad array of riparian conditions for study. I sampled each stream’s odonate and total benthic community along with both instream and vegetation-specific environmental variables. Odonate and total benthic communities were compared across study sites to identify differences in community structure and identify sensitivity to different environmental variables. Odonate community structure alone was highly correlated with riparian-specific vegetation variables. Meanwhile, standard water-quality assessment metrics used by the Missouri Department of Natural Resources were not useful to indicate riparian habitat condition, based on the total benthic community. I developed tolerance values for use in an odonate-oriented biotic index as a more appropriate metric for assessment of Ozark spring stream riparian conditions. I additionally examined two abundant damselfly species using occupancy modeling associated with riparian habitat. The two species showed different occupancy patterns in relation with the level of riparian impactedness around study sites. Overall, odonates showed greater sensitivity to riparian conditions than did total benthic communities, supporting the idea that this taxon alone is useful for biomonitoring associated with riparian structure around Ozark spring streams. The sensitivity of odonates to riparian conditions in stream ecosystems found in other Nearctic regions should be further studied to identify regional and species differences. Future studies can help land managers make informed decisions concerning riparian conservation efforts around streams by employing biomonitoring practices that incorporate this apparently riparian-sensitive taxon.

Copyright

© Cameron Riley Cheri

Open Access

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