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Travis
Brown
Department of Biological Sciences
Murray State University
Mentor: Terry
L. Derting
Title of Presentation: Effects of stream channelization and
dechannelization on mammalian species and habitat in riparian corridors.
Presented at: Kentucky Chapter of the Wildlife Society
ABSTRACT
Stream channelization reduces the diversity and abundance of many taxa.
Some channelized streams have been recently restored or "dechannelized"
in order to reverse the negative effects of channelization. I investigated
differences in habitat characteristics, mammal richness, and mammal activity
among three stream types: channelized, unchannelized, and dechannelized.
I measured mammal activity and richness at each stream type during four
seasons (spring-winter 2005/06), and sampled physical and vegetative aspects
of each stream during the summer of 2005. Riparian plant species richness
was significantly higher at the unchannelized stream than the other two
streams. The Kentucky Macroinvertebrate Bioassessment Index was highest
at the unchannelized stream, slightly lower at the channelized stream,
and much lower at the dechannelized stream. Mouse (Peromyscus, Ochrotomys,
and Reithrodontomys spp.), vole (Microtus spp.), and short-tail shrew
(Blarina spp.) activity did not differ among stream types. Richness of
terrestrial mammals, as determined by motion-sensitive cameras, did not
differ significantly among streams. Track plot surveys showed, however,
that unchannelized and dechannelized streams had significantly more terrestrial
mammal species richness than the channelized stream. Likewise, track transect
surveys, conducted in snow, showed that species richness at the unchannelized
stream was significantly higher than the channelized stream and that the
dechannelized stream did not differ from the other two. There was some
indication that bat activity was affected by an interaction between month
and stream type. Although this interaction was not significant, post hoc
tests revealed month-specific differences in bat activity among stream
types. These results suggested that channelization and dechannelization
affect habitat characteristics, mammal richness and mammal activity; however,
dechannelized streams have potential to recover many of the characteristics
of an unchannelized stream.
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