Forested Water Retention Areas

Guideline for decision makers,

forest managers and land owners

Edited byJost Armbruster, Alexandra Muley-Fritze, Ulrike Pfarr, Regina Rhodius,

Daniel Siepinann-Schinker, Benoit Sittler, Volker Späth, Micheie Tremolieres.

Heinz Rennenberg. JörgenKrisuzwieser . ... ...\' •'•-••....-.•. . " ü& .;• & ' ' • ,'r ''V- l^'Ji

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Acknowledgeme nts

SÜmrnary

Intrödüction. Jüraen Kreuzwieser*

Why dö werteed water retention areas? :Jürgen. Kreuzwieser; Bianca; Nijhof, Ulrike Pfarr*. Heinz, Rennehberg, Regina Rhodius,

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Daniel Siepmahh-Schinker;. ßenoftSiWer, Micheie Tremolieres

B1 Floodplain ecosystems important to FOWARA

B2 The River Rhine - one of Europe's largest river Systems .

B3 The Upper Rhine Valley along theFrench-German-Border

Flood protection, industrialization and changes in ecosystemIncreasing demand for energy in the 20th CenturyConsequences for flood danger and the ecosystemVariety of landuse in Baden-WürttembergVariety of landuse in Alsace

B4 The River Rhine in The Netherlands

Changes in the pastNature development along riversVariety of landuse in floodplains of The NetherlandsFunctions of the rivers

B5 Increasing knowledge in flood protection mahagement

Technical Flood Protection in the early 20* CenturyIncreasing knowledgeDuty to implement an environment-friendly OperationFlood Protection Act in The Netherlands

B6 How does the current Operation of forested retention areaslooklike? >•'••

Polder Erstein (F)Polder Altenheim (D)Basin Dietenbach (D)

B7 Comparison of pölders and basins

B8 Climate change and increasing risk öf flooding events

B9 Wh ich concerns are affected, which conflicts do occur?

B10 References

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Mow does flOpäin^ äffectförested areas?pastÄrnibruste^hanifiiikipnmann-^'r.hinkRrR^

C1 What are the characteristics of alluvial forests?

Hydrological conditions of alluvial ecosystemsGeomorphological processes create a spatially heterogenic mosaic oflandforms, soils and habitatsAdaptions of Vegetation communities

C2 How does (re)flooding influence the groundwater?

Re-flooded ecosystemsChanging nitrogen transfer after re-floodingDoes the extent of nitrogen transfer depend on the intensity, frequency orduration of floods?

C3 How does flooding affect the soil?

C4 How does flooding affect the ground Vegetation?

C5 How does flooding affect tree seedlings and rejuvenation?

C6 How does flooding influence tree growth?

C7 How tolerant are the current forests tö floods? (River Rhineand tributary facilities)

Data on damage and loss of adult trees after the 1999 flood in GermanyThreshold valuesTree damage development in consecutive yearsOther reasons for tree damage

C8 What are key factors for tree damage?

Flood heightFlood durationFlow velocityFrequencySuppressed vs. dominating treesWhat Symptoms are associated with prolonged exposure to floods?

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C9 What are the reasons for different flood tolerances of tree species? . C-47

How do plants cope with flooding?How can plants deal with flooding at the physiological level?Effects on gas exchangeConclusions for the reasons for different flood tolerance of tree species

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C10 Can pathogen agents be involved as causes of stress factors ,-i. Q-48in trees after flooding? V ,

Can the frequency of fungal infections be actively controlled on retention Sites? C-49Is there a practical way to reduce damage to trees? C-49

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C11 References C-50

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^cömmendati^

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JostÄrmbrüster, Alexandra MuleV-Fritze. Ulrike Pfarr*. Benoit Sittler, Völker Späth*

D1 How to estimate damage to current forest Stands caused byflooding?

Which data will be required in order to estimate the risk of tree damage?How to classify tree species and forest Stands due to their risk of gettingdamaged?How could a valuation matrix look like?

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D2 Which tree species will be suitable for retention areas?

D3 How to minimize tree damage in water retention basins?

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Cases where basins are planned to receive longer lasting inundation (more than10days)Cases where basins are planned to receive an inundation lasting 5 to 10 daysCases where basins are planned to receive an inundation length up to 5 days

D4 Which tree species will be suitable in water retention basins?

D5 Which silvicultural advices can be given?

D6 References

Reqommendatioris för public pärtrcipatipn in theplanning of retention areas ;Regina Rhodius*'.

Introduction

Why additional public participation?

„Pro and Cons" of additional participation

Which basic conditions must be given before the beginning ofa participation process? .

Working steps towards successful public participation

References

An hex 1; List bf Aüthbrs

: i': Scientific^ plant narnes and their English, Frehch

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*For any questions please contact the responsible authors (underlined) who will answer directly or forward your questi-on to a section author. Their Email addresses can be found in Annex 1.