A phytosociological and floristic analysis of floodplain forests along the Drava river between Maribor and Središče ob Dravi (NE Slovenia, sub-Pannonian phytogeographical region) is given. Applying the standard Central-European phytosociological method 33 relevés were made, which are classified in six associations: Salicetum albae, Carici elongatae-Alnetum glutinosae, Alnetum glutinosae s. lat., Stellario nemorum-Alnetum glutinosae, Fraxino-Populetum and Lonicero caprifolii-Quercetum roboris. In the latter a new subassociation -caricetosum albae is described. Comparison of ecological factors on the basis of Landolt indicator values has showed, that humidity of the site and nutrients are the main factors affecting the development of a vegetation type. The succession or zonation of the vegetation types goes from white willowstands (Salicetum albae) through the stands of syntaxa Fraxino-Populetumand Lonicero caprifolii-Quercetum roboris caricetosum albae to European hornbeam and pedunculate oak forests (Lonicero caprifolii-Quercetum roboris). Inbetween described successional series different phytocoenoses of black alder are found on specific growing sites. It was found, that investigated forests are poorly preserved and exposed to intense anthropogenic influences. In addition non native invasive plants also represent a big threat to this forests communities. A phytosociological and floristic comparison with floodplain forests along Mura river was made, which indicates some differences between the stands of white willow and black alder of the two rivers.
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