Ecology and vegetation of braided rivers in the European Alps with special emphasis on the Tagliamento - King of alpine rivers Norbert Müller University of Applied Sciences Erfurt, Germany 1
Contents 1 Geography of the European Alps 2 History of the European Alps 3 Ecology of alpine rivers in Europe 4 Human impact on alpine rivers 5 Tagliamento - the last large natural river in the European Alps 5.1 Morphology and vegetation 5.2 Plant diversity 5.3 Diversity of key species and exotic plants 5.4 EU Habitats and importance for nature conservation 6 Risks for the Tagliamento 7 Challenges and chances for the future 2
1. Geography of European Alps 3
Venecia 4
Geology Central Alps (< 4000 m) - Silicious (origin volcanic) Northern & South. Alps (< 3000 m) - limestone (origin sea sediments) 5
History 10.000 BC end of glaciers period 6
2 History - 4000 BC first records of burning forests and creating new pastures in the Southern - and Central Alps - 1000 BC increasing of permanent settlements in the valleys - 0 Via Claudia permanent road from the Romans across the Alps - 1500 AC main period - transformation alpine forests in meadows 7
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3. Ecology of alpine rivers in Europe 9
3.1 River types 10
3.2 Hydrodynamics Annual run-off regime of a lowland and an alpine river in Europe 11
3.3 Dynamics in morphology Catchments areas in limestone are the main sources for the bed loads which are transported during flood water events 12
When the flood water event is over the landscape has changed. 13
..for the design of islands the debris can play an essential role 14
3.4 Dynamics and structure of floodplain vegetation Spatial and temporal dimension: example for patch dynamics 1984 2004 15
3.4 Dynamics and structure of floodplain vegetation Bare & Pioneer vegetation Key species: Epilobium div. spec., Myricaria germanica Salix div. spec Typha minima, Flooding vegetation Alnus & Salix woods Dry woods Pinus div. spec. 16
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Pioneer vegetation a) species form the higher altitude debris fields and alpine meadows b) species which grow only in alpine riversides key species 18
Pioneer vegetation perennial Key species Chondrilla chondrilloides 19
Pioneer vegetation - perennial Key species Epilobium dodanei 20
Pioneer vegetation - shrubby (Salicetum elaeagnii) - Key species Salix elaeagnos 21
Pioneer vegetation - shrubby - Key species Myricaria germanica 22
Pioneer vegetation perennial - Key species Typha minima in old channels 23
Bare & Pioneer vegetation Key species: Epilobium div. spec., Myricaria germanica Salix div. spec Typha minima, Flooding vegetation Alnus & Salix woods Dry woods Pinus div. spec. 24
Flooding vegetation Alnus incana & Phragmites communis 25
Dry woods- Pinus sylvestris 26
3.5 Biology of key species Example: Typha minima Hoppe High seed production but no permanent seed bank wind & water dispersal Fast germination in newly created habitats Long root system High capability of regeneration Biennial or woody (never annual) Stress- tolerator in the sense of GRIME 1979 Meta-population concept 27
4. Human impact on alpine rivers 1500 changes catchments' area nutrient input loss biogeogr. barriers 1900 river- regulation 1950 power plant dams.. 28
Decline Myricaria germanica in the N-Alps in the last 100 years due to civil engineering measures 29
Expansion of ruderal and invasive alien species - neobiota 30
Summary 1500 changes in the catchments area.. nutrient input loss biogeogr. barriers 1900 river- regulation 1950 power plant dams.. Since 2000 river restoration and revitalization Background two European Directives a) European Union Water Frame Directive b) European Union Habitat Directive NATURA 2000 31
5. Tagliamento - the last large natural river in the European Alps Tagliamento 32
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5. 1 Morphology and vegetation 34
Upper course - transect 1 & 2 35
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Middle course - transects 3 & 4 37
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Middle course transects 5 & 6 39
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Lower course - transects 7 & 8 41
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5.2 Plant diversity (species number) in the longitude Total species number in the investigation areas 1 Mauria 124 2 Forni di Sotto 320 3 Amaro 304 Standorte 4 Cornino 5 Spilimbergo 195 266 6 Casarsa 187 7 Bolzano 209 8 Latisana 36 0 50 100 150 200 250 300 Artenzahl 45
5.3 Key species (species number) in the longitude pioneer- & floodplain vegetation Anzahl Zielarten in den Untersuchungsgebieten Mauria Pionierstandort Auwald Forno di Soto Amaro Cornino Spilinbergo Casarsa Bolzano Latisana 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 46
5.4 EU Directive Habitats & importance nature conservation a) last (semi) natural river in the Alps with all types of riparian habitats b) largest natural corridor in Europe connecting the continental with the Mediterranean biome Example coherence of the key species Calamagrostis pseudophragmites 47
3220 Alpine rivers and the herbaceous vegetation along their banks 48
3230 Alpine rivers with Myricaria germanica (Salici-Myricariertum) 49
3240 Alpine rivers with Salix eleagnos (Salicetum eleagni) 50
7230 Alkaline Fens 7240* Alpine pioneer formations 51
91E0* Alluvial Forests (Alnion incanae, Salicion albae) 52
91F0 Riparian mixed forests along great rivers (Ulmenion minoris) 53
3270 Rivers with muddy banks (Chenodion rubri, Bidention) 54
EU Directive Habitats und connectivity 55
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6. Risks for the Tagliamento Old technical plans of the Region Friaul Venetien for highwater prevention (Hochwasserschutz) of Latisana Latente Gefährdungen Technical constructions along the river and their z. B. Fella Deforestation and agricultural landuse of the floodplain area Biological Invasions 57
Geplante Hochwasserrückhaltebecken zwischen Pinzano und Dignano 58
Exotic species (species number) in the longitude pioneer- & floodplain vegetation Artenzahl Neophyten in den Untersuchungsgebieten (UG) auf Pionier- und Auwaldstandorten Mauria Pionierstandort Auwald Forni d.s. Armaro Cornino Spilenbergo Carsarsa Bolzano Latisana 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 59
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7 Challenges and chances for the future 1 International Protection of the whole Tagliamento river corridor as a UNESCO World Heritage Site 2 European Union Support the local authorities (Friaul and Ventia) along the Tagliamento with special programs of the EU to protect biodiversity e. g. LIFE + Development of the area as a model region for sustainable river management within the EU Water Frame Directive 61
Thank you! 62