Reed-bed decline phenomenon in central Italy: the case of Montepulciano lake.

Our contribute is part of a more comprehensive study about the die-back syndrome of Phragmites australis (Cav.) Steud. in central Italy. The lacustrine ecosystem of Montepulciano lake, designed as a Site of Community Importance (SCI) according to the European 92/43/EEC ‘Habitats’ Directive, has been investigated performing a diachronic analysis of reed vegetation maps. Moreover analyses of macromorphological traits of common reed beds together with selected sediments and interstitial water chemical parameters and flooding were done. Main aim is to check the regression of reed-bed and its relations with these factors. Our results highlighted that, in some areas of the reed-beds, macromorphological traits of reed decline are the typical ones of the die-back syndrome reported for other sites. The results of the investigations in Montepulciano lake confirm that stressing conditions (e.g. flooding) co-occurring with the presence of some chemical elements (e.g. heavy metals) in the soil may have an effect on the decline of common reed.