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<div><font face="Geneva"><i>Journal of Applied Ecology</i> 2007 44,
1145-1155</font><br>
<font face="Geneva">© 2007 British Ecological Society</font><br>
</div>
<div><font face="Geneva"><b>The use of large wood in stream
restoration: experiences from 50 projects in Germany and
Austria</b></font></div>
<div><font face="Geneva"><br></font></div>
<div><font face="Geneva">JOCHEM KAIL, DANIEL HERING, SUSANNE MUHAR,
MARC GERHARD and SABINE PREIS</font></div>
<div><font face="Geneva"><br>
Summary</font><br>
<font face="Geneva"><br>
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.</font><br>
<font face="Geneva"><br>
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.</font><br>
<font face="Geneva"><br>
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.</font><br>
<font face="Geneva"><br>
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.</font><br>
<font face="Geneva"><br>
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.</font><br>
<font face="Geneva"><br>
Key-words: alpine streams, lowland streams, monitoring, mountain
streams, passive restoration, restoration success, soft-engineering,
woody debris</font><br>
<font face="Geneva"><br>
Journal of Applied Ecology (2007) 44, 1145-1155 doi:
10.1111/j.1365-2664.2007.01401.x</font></div>
<div><font face="Geneva">Correspondence: Jochem Kail, University of
Duisburg-Essen, Department of Hydrobiology, D-45117 Essen,
Germany</font></div>
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<div><font face="Bookman Old Style" size="-1"
color="#000000"
>====================================================================<span
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"Limiting atmospheric carbon dioxide (CO2) concentrations to low
levels requires strategies to manage anthropogenic carbon emissions
from terrestrial systems as well as fossil fuel and industrial
sources."<br>
<br>
Marshall Wise,<i> et al.</i> Implications of Limiting CO2
Concentrations for Land Use and Energy.<i> Science</i> 324, 1183
(2009); DOI: 10.1126/science.1168475</font></div>
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