docBiodiversity of the River Meuse floodplain
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Biodiversity of the River Meuse floodplain
Biodiversity of the River Meuse floodplain in the context of the Common Meuse restoration programme Kris Van Looy Research Institute for Nature and Forest, Brussels, Belgium Restoration of river habitats and species 1. Common Meuse floodplain biodiversity 2. River restoration and reference conditions • Hydromorphological alterations • Habitat fragmentation & species isolation • Restoration concept • Reference conditions • Restoration experiences 3. Indicators floodplain biodiversity • River corridor plants in isolation • Flood dispersal determines genetic structure • Modelling approach • Indicator favourable conservation status Kris Van Looy 1 The River Meuse Introduction River type: – rain-fed river – Source altitude 409 m – Length 900 km – catchment area: 34,500km² - 6 reaches – Common Meuse reach km 450-500 – Natura2000 B:floodplain meadows/forests, NL: river bed Floodplain diversity river reaches soortverdeling ecoregio's Log species richness Meuse reaches: reaches: I: Lorraine II: Ardennen III: Common Meuse IV: Peelhorst Meuse V: Sand Meuse VI: Tidal Meuse 3 2,5 2 3-5 5 4 3 2 1,5 1 1 0,5 0 I II III IV V Meuse reaches 1 Ecoregions: 1: Fluviatiel floodplain meadow species 2: Kempen riparian ground beetles 3: 2 3 4 5 6 Brabant riparian macroinvertebrates 4: Kalkstreek Maastrajecten 5: Ardennen, Vogezen, Eifel VI Van Looy ea. 2006 Journal of Biogeography 2 Hydromorphological character river Meuse • free-flowing meandering river 3000 stretch 2500 • rain-fed river (10-3000m³/s) 2000 • channelized bed, gravel mining 1500 •deeply incised river bed 1000 • disrupted floodplains (winter dikes) 500 0 5/11/02 5/03/03 5/07/03 5/11/03 5/03/04 Kris Van Looy & Alexander Van Braeckel Hydromorphological alterations: bed incision AVERAGE BED ELEVATION Common Meuse 45 1937; GM 40 m 1947; GM 40 m 1959; GM 40 m 1967 40 1970 35 1984; Peil8495.xls 1995; Meander 2004; Meander 2007; Meander 30 25 Strong incision by gravel mining 20 55 53 51 49 47 45 43 41 39 37 35 33 31 29 27 25 23 21 19 17 15 15 elevation [m+NAP] 1976 Gradual lowering, still going on rkm Meuse Kris Van Looy & Alexander Van Braeckel 3 Habitat fragmentation Habitats are fragmented by river regulation and land use intensification Flood frequency ~ species composition & Species diversity Van Looy et al. al. 2003 Belgian Journal of Botany Location of sampled forest fragments in the Meuse valley Restoration concept Hoge climaxvegetatie Kris Van Looy & Alexander Van Braeckel 4 Hydromorphological references 5 Hydromorfological, historical and actual reference Hoge climaxvegetatie Restoration experiences Pilot projects showed a restoration of hydromorphology, habitats and species Kris Van Looy & Alexander Van Braeckel 6 Hydromorphological aspects in the restoration of river habitats and species River bed recovers •in elevation •in habitat •in species • Waterplants Potamogeton nodosus, ranunculus fluitans • Dragonflies gomphus flavipes Pilot project Kris Van Looy & Alexander Van Braeckel Habitat restoration November 2003 • July 2004 7 Species recolonisation in pilot projects plot 1 Amara aenea Lionychus quadrillum Bembidion atrocoeruleum Bembidion punctulatum Bembidion tetracolum plot 2 Bembidion atrocoeruleum Amara aenea Bembidion femoratum Bembidion decorum Bembidion decorum plot 3 Bembidion atrocoeruleum Bembidion tetracolum Bembidion femoratum Bembidion decorum Amara aenea Bembidion femoratum Lionychus quadrillum Bembidion tetracolum Bembidion punctulatum Floodplain diversity and species isolation Species diversity ~ patch area rare river corridor plants in isolated relics 8 Genetics of species recovery • Annual species (Erisymum cheiranthoides) metapopulation dynamics • Mixed annual-perennial pioneer species (Sisymbrium chrysanthum) shifting cloud with sattelite populations • Perennial floodplain species (Origanum vulgare) patchy population P. Breyne (Inbo), O. Honnay, H. Jacquemyn (Univ. Leuven) Floodplain conditions in modelling Strong gradient • alcalinity • Salt concentration – Flood influence pH • pH ~ distance, contact river • EC ~ flood frequency, texture – vegetation • composition/type • Spatial and temporal shift Zoutconcentratie – Modelling • Different types • Patches in space and time 9 Modelling approach • Dry river grasslands:4 types • • • • Overbank gravel deposition: Alysso-sedion albi Overbank sand deposition: Sedo-thymetum pulegioides Gravel deposition floodplain: Thero-airion Sand deposition floodplain: Medicagini-avenetum pubescens Evaluation Fauna Bird Target species parameter Habitat type Marsh harrier area & frequency Marsh Night heron Kingfisher Side water length & area Little plover Mammal Flora Steep wall Gravel bar Beaver bank length Isolated lake Otter area Marshland Amfibian Tree frog area & frequency Isolated lake Insect Gomphus bank length Running water frequency Nevengeul Potamogeton nodosus Ranunculus fluitans Ondiepe bedding Inula brittanica Dynamisch grasland Euphorbia esula Dynamisch grasland Corrigiola litoralis Gravel bar Salvia pratensis Hogeweerdgrasland Galeopsis angustifolia High gravel bar Senecio erucifolius Hogeweerdruigte Eryngium campestre Dry river grassland Thymus pulegioides Dry river grassland Corydalis solida Hardwood forest 10 Thank you and welcome 11 Welcome to the future 12