Sci Total Environ. 2016 Feb 15;544:339-53. doi: 10.1016/j.scitotenv.2015.11.103. Epub 2015 Dec 3.
- 1Department
of Geomorphology, Faculty of Geography and Regional Studies, University
of Warsaw ul. Krakowskie Przedmiescie 30, 00-927 Warsaw, Poland.
Electronic address: dagiriat@uw.edu.pl.
- 2Department
of Geomorphology, Institute of Geography and Spatial Management,
Jagiellonian University, ul. Gronostajowa 7, 30-387 Cracow, Poland.
Electronic address: elzbieta.gorczyca@uj.edu.pl.
- 3Department
of Geomorphology, Institute of Geography and Spatial Management,
Jagiellonian University, ul. Gronostajowa 7, 30-387 Cracow, Poland.
Electronic address: mateusz.sobucki@uj.edu.pl.
Abstract
Beaver (Castor sp.) can change the riverine environment through dam-building and other activities. The European beaver (Castor fiber)
was extirpated in Poland by the nineteenth century, but populations are
again present as a result of reintroductions that began in 1974. The
goal of this paper is to assess the impact of beaver activity on montane
fluvial system development by identifying and analysing changes in
channel and valley morphology following expansion of beaver into a 7.5
km-long headwater reach of the upper Wisłoka River in southeast Poland.
We document the distribution of beaver in the reach, the change in river
profile, sedimentation type and storage in beaver ponds, and assess how
beaver dams and ponds have altered channel and valley bottom
morphology. The upper Wisłoka River fluvial system underwent a series of
anthropogenic disturbances during the last few centuries. The rapid
spread of C. fiber
in the upper Wisłoka River valley was promoted by the valley's
morphology, including a low-gradient channel and silty-sand deposits in
the valley bottom. At the time of our survey (2011), beaver ponds
occupied 17% of the length of the study reach channel. Two types of
beaver dams were noted: in-channel dams and valley-wide dams. The
primary effect of dams, investigated in an intensively studied 300-m
long subreach (Radocyna Pond), was a change in the longitudinal profile
from smooth to stepped, a local reduction of the water surface slope,
and an increase in the variability of both the thalweg profile and
surface water depths. We estimate the current rate of sedimentation in
beaver ponds to be about 14 cm per year. A three-stage scheme of fluvial
processes in the longitudinal and transverse profile of the river
channel is proposed. C. fiber reintroduction may be considered as another important stage of the upper Wisłoka fluvial system development.
Copyright © 2015 Elsevier B.V. All rights reserved.
KEYWORDS:
Beaver ponds; Fluvial processes; Fluvial system; Grain size; Land use change; Silting
