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Titel |
Impacts of beaver dams on hydrologic and temperature regimes in a mountain stream |
VerfasserIn |
M. Majerova, B. T. Neilson, N. M. Schmadel, J. M. Wheaton, C. J. Snow |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1027-5606
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Digitales Dokument |
URL |
Erschienen |
In: Hydrology and Earth System Sciences ; 19, no. 8 ; Nr. 19, no. 8 (2015-08-11), S.3541-3556 |
Datensatznummer |
250120788
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Publikation (Nr.) |
copernicus.org/hess-19-3541-2015.pdf |
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Zusammenfassung |
Beaver dams affect hydrologic processes, channel complexity, and stream
temperature in part by inundating riparian areas, influencing
groundwater–surface water interactions, and changing fluvial processes
within stream systems. We explored the impacts of beaver dams on hydrologic
and temperature regimes at different spatial and temporal scales within a
mountain stream in northern Utah over a 3-year period spanning pre- and
post-beaver colonization. Using continuous stream discharge, stream
temperature, synoptic tracer experiments, and groundwater elevation
measurements, we documented pre-beaver conditions in the first year of the
study. In the second year, we captured the initial effects of three beaver
dams, while the third year included the effects of ten dams. After beaver
colonization, reach-scale (~ 750 m in length) discharge
observations showed a shift from slightly losing to gaining. However, at the
smaller sub-reach scale (ranging from 56 to 185 m in length), the
discharge gains and losses increased in variability due to more complex flow
pathways with beaver dams forcing overland flow, increasing surface and
subsurface storage, and increasing groundwater elevations. At the reach
scale, temperatures were found to increase by 0.38 °C (3.8 %),
which in part is explained by a 230 % increase in mean reach residence
time. At the smallest, beaver dam scale (including upstream ponded area,
beaver dam structure, and immediate downstream section), there were notable
increases in the thermal heterogeneity where warmer and cooler niches were
created. Through the quantification of hydrologic and thermal changes at
different spatial and temporal scales, we document increased variability
during post-beaver colonization and highlight the need to understand the
impacts of beaver dams on stream ecosystems and their potential role in
stream restoration. |
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