[MCN] Rivers' restoration: Restore big in-river wood: 5 references
Lance Olsen
lance at wildrockies.org
Tue Aug 18 12:42:05 EDT 2015
1-Journal of Applied Ecology 2007 44, 1145-1155
© 2007 British Ecological Society
doi: 10.1111/j.1365-2664.2007.01401.x
The use of large wood in stream restoration:
experiences from 50 projects in Germany and
Austria
JOCHEM KAIL*, DANIEL HERING*, SUSANNE MUHAR_, MARC GERHARD_ and SABINE PREIS_
*University of Duisburg-Essen, Department of
Hydrobiology, D-45117 Essen, Germany
_-University of Natural Resources and Applied
Life Sciences, Department
Water-Atmosphere-Environment, A-1180 Vienna,
Austria
y-Institute for Landscape Planning and Nature
Conservation, Herrenhäuser Str. 2, D-30419
Hannover, Germany
Key-words: alpine streams, lowland streams,
monitoring, mountain streams, passive
restoration, restoration success,
soft-engineering, woody debris
Summary
1.Wood is increasingly used in restoration
projects to improve the hydromorphological and
ecological status of streams and rivers. However,
despite their growing importance, only a few of
these projects are described in the open
literature. To aid practitioners, we conducted a
postal mail survey to summarize the experiences
gained in central Europe and compile data on 50
projects.
2.Our results indicated the potential for
improvement from an ecological point of view, as
the number and total wood volume, and the median
volume of single wood structures placed in the
streams per project, were low compared with the
potential natural state. Moreover, many wood
structures were placed nearly parallel to the
water flow, reducing their beneficial effect on
stream hydraulics and morphology.
3. Restoration success has been monitored in only
58% of the projects. General conclusions drawn
include the following. (i) The potential effects
of wood placement must be evaluated within a
watershed and reach-scale context. (ii) Wood
measures are most successful if they mimic
natural wood. (iii) Effects of wood structures on
stream morphology are strongly dependent on
conditions such as stream size and hydrology.
(iv) Wood placement has positive effects on
several fish species. (v) Most projects revealed
a rapid improvement of the hydromorphological
status.
4.Most of the wood structures have been fixed,
called 'hard engineering'. However, soft
engineering methods (use of non-fixed wood
structures) are known to result in more natural
channel features for individual stream types,
sizes and sites, and are significantly more
cost-effective.
5.Synthesis and applications. Large wood has been
used successfully in several projects in central
Europe, predominantly to increase the general
structural complexity using fixed wood
structures. Our results recommend the use of less
costly soft engineering techniques (non-fixed
wood structures), higher amounts of wood, larger
wood structures and improved monitoring
programmes for future restoration projects
comparable with those in this study. We recommend
the use of 'passive restoration' methods
(restoring the process of wood recruitment on
large scales) rather than 'active restoration'
(placement of wood structures on a reach scale),
as passive restoration avoids the risk of
non-natural amounts or diversity of wood loading
developing within streams. Local, active
placement of wood structures must be considered
as an interim measure until passive restoration
methods have increased recruitment sufficiently.
========================================
2- Earth Surface Processes and Landforms 35, 618-625 (2010)
Copyright © 2010 John Wiley & Sons, Ltd.
Published online 11 March 2010 in Wiley
InterScience (www.interscience.wiley.com)
DOI: 10.1002/esp.1966
Large in-stream wood studies: a call for common metrics
Ellen Wohl,1 Daniel A. Cenderelli,2 Kathleen A.
Dwire,3 Sandra E. Ryan-Burkett,3 Michael K.
Young4 and Kurt D. Fausch5
1-Department of Geosciences, Colorado State University, Fort Collins, CO, USA
2-USDA Forest Service, Stream Systems Technology Center, Fort Collins, CO, USA
3-USDA Forest Service, Rocky Mountain Research Station, Fort Collins, CO, USA
4-USDA Forest Service, Rocky Mountain Research
Station, Forestry Sciences Lab, Missoula, MT, USA
5-Department of Fish, Wildlife and Conservation
Biology, Colorado State University, Fort Collins,
CO, USA
Received 16 October 2009; Accepted 2 November
2009 *Correspondence to: Ellen Wohl, Department
of Geosciences, Colorado State University, Fort
Collins, CO 80523-1482, USA. E-mail:
ellenw at cnr.colostate.edu
ABSTRACT: During the past decade, research on
large in-stream wood has expanded beyond North
America's Pacific Northwest to diverse
environments and has shifted toward increasingly
holistic perspectives that incorporate processes
of wood recruitment, retention, and loss at
scales from channel segments to entire
watersheds. Syntheses of this rapidly expanding
literature can be facilitated by agreement on
primary variables and methods of measurement. In
this paper we address these issues by listing the
variables that we consider fundamental to studies
of in-stream wood, discussing the sources of
variability in their measurement, and suggesting
more consistency in future studies. We recommend
23 variables for all studies of in-stream wood,
as well as another 12 variables that we suggest
for studies with more specific objectives. Each
of these variables relates either to the size and
characteristics of in-stream wood, to the
geomorphic features of the channel and valley, or
to the ecological characteristics of the riparian
zone adjacent to the study reach. The variables
were derived from an overview of those cited in
the literature and from our collective field
experiences. Copyright © 2010 John Wiley & Sons,
Ltd.
----------------------------------------------------
3-Earth Surface Processes and Landforms
Large woody debris in a mountain stream of the Chilean Andes 1675
Earth Surf. Process. Landforms 32, 1675-1692 (2007)
Published online 18 September 2007
DOI: 10.1002/esp.1593
Characteristics, distribution and geomorphic role
of large woody debris in a mountain stream of the
Chilean Andes
Andrea Andreoli, Francesco Comiti* and Mario Aristide Lenzi
Department of Land and Agroforest Environments,
University of Padova, Viale dell'Università No.
16, 35020 Legnaro (PD), Italy
Abstract
The paper presents an analysis of amounts,
characteristics and morphological impact of large
woody debris (LWD) in the Tres Arroyos stream,
draining an old-growth forested basin (9·1 km2)
of the Chilean Southern Andes. Large woody debris
has been surveyed along a 1·5 km long channel
section with an average slope of 0·07 and a
general step-pool/cascade morphology. Specific
wood storage is very high (656 -710 m3 ha-1),
comparable to that recorded in old-growth
forested basins in the Pacific Northwest. Half of
the LWD elements were located on the active
floodplain, and around two-thirds of LWD elements
were found in accumula- tions. Different types of
log jam were observed, some heavily altering
channel morphology (log-steps and valley jams),
while others just line the channel edges
(bankfull bench jams). Log-steps represent
approximately 22% of all steps, whereas the
elevation loss due to LWD (log-steps and valley
jams) results in 27% loss of the total stream
potential energy. About 1600 m3 of sediment is
stored in the main channel behind LWD structures,
corresponding to approximately 150% of the annual
sediment yield.
Copyright © 2007 John Wiley & Sons, Ltd.
Keywords: large woody debris; channel morphology; valley jams; log-steps; Andes
------------------------------------------------------
4- River Research and Applications (2011)
Published online in Wiley Online Library (wileyonlinelibrary.com)
DOI: 10.1002/rra.1532
A LIDAR-DERIVED EVALUATION OF WATERSHED-SCALE
LARGE WOODY DEBRIS SOURCES AND RECRUITMENT
MECHANISMS: COASTAL MAINE, USA
A. KASPRAK,a* F. J. MAGILLIGAN,b K. H. NISLOWc and N. P. SNYDERd
a Department of Earth Sciences, Dartmouth
College, Hanover, New Hampshire 03755, USA
b Department of Geography, Dartmouth College, Hanover, New Hampshire 03755, USA
c USDA Northern Research Station, Amherst, Massachusetts 01103, USA
d Department of Earth and Environmental Sciences,
Boston College, Chestnut Hill, Massachusetts
02467, USA
ABSTRACT
In-channel large woody debris (LWD) promotes
quality aquatic habitat through sediment sorting,
pool scouring and in-stream nutrient retention
and transport. LWD recruitment occurs by numerous
ecological and geomorphic mechanisms including
channel migration, mass wasting and natural tree
fall, yet LWD sourcing on the watershed scale
remains poorly constrained. We developed a rapid
and spatially extensive method for using light
detection and ranging data to do the following:
(i) estimate tree height and recruitable tree
abundance throughout a watershed; (ii) determine
the likelihood for the stream to recruit
channel-spanning trees at reach scales and assess
whether mass wasting or channel migration is a
dominant recruitment mechanism; and (iii)
understand the contemporary and future
distribution of LWD at a watershed scale. We
utilized this method on the 78 km-long
Narraguagus River in coastal Maine and found that
potential channel-spanning LWD composes
approximately 6% of the valley area over the
course of the river and is concentrated in
spatially discrete reaches along the stream, with
5 km of the river valley accounting for 50% of
the total potential LWD found in the system. We
also determined that 83% of all potential LWD is
located on valley sides, as opposed to 17% on
floodplain and terrace surfaces. Approximately 3%
of channel-spanning vegetation along the river is
located within one channel width of the stream.
By examining topographic and morphologic
variables (valley width, channel sinuosity,
valley-side slope) over the length of the stream,
we evaluated the dominant recruitment processes
along the river and often found a spatial
disconnect between the location of potential
channel-spanning LWD and recruitment mechanisms,
which likely explains the low levels of LWD
currently found in the system. This rapid method
for identification of LWD sources is extendable
to other basins and may prove valuable in
locating future restoration projects aimed at
increasing habitat quality through wood additions.
Copyright © 2011 John Wiley & Sons, Ltd.
key words: large woody debris; lidar; river
restoration; habitat Received 5 November 2010;
Revised 16 March 2011; Accepted 30 March 2011
-------------------------------------------------
5- Earth Surface Processes and Landforms 36, 1137-1151 (2011)
Copyright © 2011 John Wiley & Sons, Ltd.
Published online 1 March 2011 in Wiley Online Library (wileyonlinelibrary.com)
DOI: 10.1002/esp.2135
Distribution and characterization of in-channel
large wood in relation to geomorphic patterns on
a low-gradient river
Bertrand Moulin,1 Edward R. Schenk2* and Cliff R. Hupp2
1 AEMGEO - University of Lyon, CNRS UMR 5600 ?
Environnement Ville et Société, Site of École
Normale Supérieure de Lyon, 15 Parvis René
Descartes, BP 7000, 69342, Lyon cedex 07, France
2 US Geological Survey, 12205 Sunrise Valley Dr., Reston, VA 20192, USA
Received 30 August 2010; Revised 5 January 2011; Accepted 10 January 2011
* Correspondence to: E. R. Schenk, US Geological
Survey, 12205 Sunrise Valley Dr., Reston, VA
20192, USA. E?mail: eschenk at usgs.gov
ABSTRACT: A 177 river km georeferenced aerial
survey of in-channel large wood (LW) on the lower
Roanoke River, NC was conducted to determine LW
dynamics and distributions on an eastern USA
low-gradient large river. Results indicate a
system with approximately 75% of the LW available
for transport either as detached individual LW or
as LW in log jams. There were approximately 55
individual LW per river km and another 59 pieces
in log jams per river km. Individual LW is a
product of bank erosion (73% is produced through
erosion) and is isolated on the mid and upper
banks at low flow. This LW does not appear to be
important for either aquatic habitat or as a
human risk. Log jams rest near or at water level
making them a factor in bank complexity in an
otherwise homogenous fine-grained channel. A
segmentation test was performed using LW
frequency by river km to detect breaks in
longitudinal distribution and to define
homogeneous reaches of LW frequency. Homogeneous
reaches were then analyzed to determine their
relationship to bank height, channel width/depth,
sinuosity, and gradient. Results show that log
jams are a product of LW transport and occur more
frequently in areas with high snag
concentrations, low to intermediate bank heights,
high sinuosity, high local LW recruitment rates,
and narrow channel widths. The largest
concentration of log jams (21.5 log jams/km)
occurs in an actively eroding reach. Log jam
concentrations downstream of this reach are lower
due to a loss of river competency as the channel
reaches sea level and the concurrent development
of unvegetated mudflats separating the active
channel from the floodplain forest. Substantial
LW transport occurs on this low-gradient,
dam-regulated large river; this study, paired
with future research on transport mechanisms
should provide resource managers and policymakers
with options to better manage aquatic habitat
while mitigating possible negative impacts to
human interests. Copyright © 2011 John Wiley &
Sons, Ltd.
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======================================
Professor Tim Benton, Research Dean in the
Faculty of Biological Sciences and co-author of
the research, said: "We are increasingly finding
that the appropriate area needed to best manage
biodiversity is greater than the area managed by
individuals - the same is true of farms within
the countryside - and so the biggest challenge is
to find ways that help neighbours to co-operate.
http://www.leeds.ac.uk/news/article/695/gardeners_must_unite_to_save_britains_wildlife
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