Benefits and Challenges for Nature Conservation in Assessing Ecosystem Services in Rivers and Floodplains Case studies from Germany and Europe

Transcription

1 7th Sino-German Workshop on Biodiversity Conservation - 7/7/2014 Benefits and Challenges for Nature Conservation in Assessing Ecosystem Services in Rivers and Floodplains Case studies from Germany and Europe Photo: A. Künzelmann, UFZ Mathias Scholz 1, Dietmar Mehl 2, Christiane Schulz-Zunkel 1, Hans Kasperidus 1, Wanda Born 1, Klaus Henle 1 UFZ: 1 - Department Conservation Biology Biota. 2 Institut für ökologische Forschung und Planung GmbH Institut für ökologische Forschung und Planung GmbH BfN: Thomas Ehlert

2 Contents 1. Introduction 2. National Floodplain Program 3. ESS in Floodplains 4. Discussion and outlook Foto: P. Ibe Foto: P. Ibe Foto: P. Ibe

3 Introduction Near-natural alluvial areas are a rarity Lack of data about spatial extension and status of floodplains Reasonable and precise data a needed for revitalisation activities Consideration of land use conflicts Focus on ESS in floodplains! Source: Scholz et al SEITE 3

4 The National Floodplain Inventory (Background) Spatial extension of floodplains of 79 rivers in Germany, no tidal section! Minimum catchment size km 2 ca km of river length Plotting of the geomorphologic floodplain Marking out rivers, active and inactive floodplains Inventory of land uses and protected areas First Assessment of the ecological status of floodplains in Germany source:

5 Nationwide inventory of loss and status of German floodplains (Background) Loss of indundation area Source: 24_auenzustan dsbericht.html

6 Status of German floodplains (Background) Status of active floodplains Status of floodplain modification: : Very low low medium high Very high Not assessed Source: Brunotte et al BfN:

7 ` Provisioning services (j Food Energy Urbanisation w j Transport Water Raw material (` ZvW Gen reservoir ifossil raw material Regulating services à(g Pollination U Õ ( ±Õ Climate ( Ì [q Erosion Self purification ( P e?^waterregeneration (,Hazard mitigation Basic ESS of Rivers and Floodplains (after MEA 2005) (A Education Ø(Recreation (ñculture 92B(Landscape (Î (Ù Matter flux (YQ Q! Water Cycle Soil formation (M Biodiversity Figure:, TEEB DE, UFZ modified. Background photo: Krumme Spree near Plattkow; Isabell Hiekel, Cultural services Basic services

8 Assessment of ESS in floodplains in Germany Methodological approach Based on the German floodplain inventory of 79 streams Assessment unit 1-km-segments Focus on flood retention capacity, nutrient retention, carbon sequestration and floodplain biodiversity approach based on reviewed case studies, derived proxies for ecological coherences, and standard values Integration of economic aspects for some functions (e.g. mitigation costs) Source: Scholz et al. 2012

9 Fotos: A. Künzelsmann Biodiversity and habitat function

10 Aspect: Floodplain Biodiversity Goal: identification of Hotspots for biodiversity in floodplains Priorities and Potentials Assessment of Floodplain biodiversity on a national level like Germany only by integrating features/surrogates feasible Existing national floodplain inventory has assessed morphology and hydrological conditions in combination with land use here focus on Biodiversity from the viewing point of nature conservation which includes floodplain typical habitats of natural but also traditional man-made landscapes

11 Biodiversity and habitat function sehr gering 20% sehr hoch 4% hoch 27% gering 27% mittel 22% floodplain biodiversity hotspots are located along free flowing river stretches of the lowlands - only 4% remains in a very good status Quelle: Scholz et al. 2012

12 Flood retention Photo: A. Künzelmann, UFZ

13 Flood retention Strategic background Flood retention in floodplains: They act as a sponge and regulate the water volume, as they cut off flood peaks and release water during low-flow conditions Measures of river and floodplain restoration can reduce flood peaks Example River Elbe: Realization of 19 new retention areas (15 Dike relocations, 4 flood polder) have effects to lower extreme flooding events in the downstream areas flooding with short peaks show especially effects locally in lowering the water level Source: Busch & Hammer 2006, Mehl et al. 2012, Scholz et al. 2012

14 Loss of flood retention sehr Very hoher high Verlust loss 14% sehr Very geringer low Verlust loss 9% geringer Low loss Verlust 21% 21% hoher High Verlust loss 29% deutlicher Distinct Verlust loss 27% Loss of flood retention Very low Low Distinct High Very high Loss of flood retention is reflecting the main hydraulic factors, expansion of active floodplains, loss of floodplains and the roughness of the land-use in active floodplains. Only 30% of the floodplains have a high flood retention capacity Institut für ökologische Forschung und Planung GmbH Source: Mehl et al. 2012

15 Nutrient retention Photo: C. Schulz-Zunkel

16 Nutrient retention in floodplains N-retention P-Retention Main process Denitrification (Mulholland 2008, Verhoeven et al. 2006, van der Lee et al. 2004, Venohr et al. 2003, Kronvang et al. 1999) Main process Sedimentation (Verhoeven et al. 2006, van der Lee et al. 2004, Kronvang et al. 1999) determining factors for nutrient retention in floodplains: - Discharge of nutrients in the river Source: Schulz-Zunkel et al. 2012, Scholz et al inundation area - inundation time - soil properties - Land use

17 Nutrient retention in floodplains Potential Nutrient retention on average 7-9% N and 11% P of annual river load, but P-retention can increase up to 50% (Elbe) in case the floodplains are inundated; calculated marginal costs for the entire nutrient retention in the riparian zones and rivers reaches a maximum of 540 million Euros annually. Source: Schulz-Zunkel et al. 2012, Scholz et al. 2012

18 Elbe Rhein Weser Donau Ems Main Spree Leine Havel Saale Lippe Oder Werra Mulde N-Retention Potential N- retention of the 25 largest floodplains in Germany [t/a]. Aller Bode Isar Peene Weiße Elster Amper Inn Lahn Elde Naab Ruhr N-Retention max [t/a] N-Retention min [t/a] Source: Schulz-Zunkel et al. 2012

19 Carbon stocks and greenhouse gas emissions Foto: K. Henle

20 Distribution of organic soils in the morphologic floodplains high carbon sequestration in organic and mineral floodplain soils, but high potential of greenhouse gas emissions depending on land use intensity Organic soils Morph. floodplain Carbon stock in active floodplains Auenböden/ Gleye 41 Mio. t C Terrestrische Böden 7 Mio. t C Moorböden 109 Mio. t C Data Source: BÜK1000 Source: Scholz et al. 2012

21 calculation of greenhouse gas emissions for peat lands soils in active floodplains, summarized for main catchments CO2e in 1000 t a Rhein Donau Ems Weser Elbe Oder Ostseezuflüsse Emissions for this area were calculated at 2.53 million t CO 2 - equivalents per year. Correspond to the CO 2 -emissions from 1,265,750 cars in a year Flussgebiete rezente Aue Altaue Source: Mehl et al. 2012, Scholz et al. 2012

22 Summary: Floodplain functions and services Case study Germany- Summery Evaluation of four ecosystem functions Only 30% of the floodplains have a high flood retention capacity Nutrient retention on average 7-9% N and 11% P of annual river load, but P- retention can increase up to 50% (Elbe) high carbon sequestration in organic and mineral floodplain soils, but high potential of greenhouse gas emissions depending on land use intensity floodplain biodiversity hotspots are located along free flowing river stretches of the lowlands - only 4% remains in a very good status Source: Scholz et al Photo: A. Künzelmann, UFZ Photo: C. Schulz-Zunkel Photo: K. Henle

23 Dike relocation Lenzen 420 ha Data before and after dike relocation Assessment Source: SCHOLZ, M., KASPERIDUS, H.D., SCHULZ-ZUNKEL, C. & D. Mehl (2012): Betrachtung von Auenfunktionen vor und nach der Deichrückverlegung bei Lenzen. Auenreport Spezial 2012: Foto: M. Scholz

24 Comparison of land use in the active floodplain before and after dike relocation before after

25 Nutrient retention Use of N-retention by denitrification rates P-retention by sedimentation N-retention Before and after dike relocation N-Retention vor und nach DRV in N-D-Ret in t -a vor DRV before nach DRV after Results: N-Retention t -a P-Retention vor und nach DRV in n t -a P-Retention 0,1 2,1t -a vor DRV before after nach DRV 0,0 0,5 1,0 1,5 2,0 2,5

26 Ongoing or future restoration projects: Lebendige Luppe/Leipzig Revitalisation of former water courses of the River Luppe; Financial support by The National Program for Biodiversity (BfN/BMU) Duration Lebendige Luppe is a shared responsibility between the City of Leipzig and City of Schkeuditz and NABU Sachsen. Scientific monitoring and evaluation: UFZ &Uni Leipzig Main focus on ecosystem services 26 Department of Urban Green Areas and Watercourses 26

27 Project Dimensions, Preferred Water Course, and Construction Sections The preferred water course was established during feasibility studies in 2006 and 2009 The blue lines show existing water courses The purple and pink lines show the preferred water course to restore 27 Department of Urban Green Areas and Watercourses 27

28 Conclusions and Outlook First overview on a national scale National floodplain inventory is suitable for large scale analysis on ESS Monetisation is depending on the quality of data and assessed functions Assessing other ESS in the floodplain context is needed Not always synergies between ESS and biodiversity Trad-offs can occur Lacks in data quality will probably resolved in the future by better combining existing data and using new data coming from other disciplines Local analysis and assessments need more precise data More case studies are needed which are addressing ESS in regard to restoration Source: Scholz et al. 2012

29 Read the entire story! okosystemfunktionen-von-flussauen.html Source: Scholz, M., Mehl, D., Schulz-Zunkel, C., Kasperidus, H.D., Born, W. & K. Henle (2012): Ökosystemfunktionen von Flussauen - Analyse und Bewertung von Hochwasserretention, Nährstoffrückhalt, Kohlenstoffvorrat, Treibhausgasemissionen und Habitatfunktion. Analysis and evaluation of ecosystem functions and services of floodplains in Germany. Naturschutz und Biologische Vielfalt 124: 257 p SEITE 29

30 Conclusions and Outlook At European level: FP7 projects like BioFresh on Global freshwater conservation: Source: Scholz et al. 2012

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33 Many thanks for your attention Foto: M. Scholz