Valsorda, Gualdo Tadino - Viola eugeniae Parl.
D. Gigante, F. Maneli, R. Venanzoni
Department of Applied Biology, University of Perugia, Borgo XX giugno, 74, I-06121 Perugia, Italy
The results of a study about Mediterranean temporary wet habitats in central inland Italy are here presented. The surveyed phytocoenoses are developed in pools and waterlogged soils and each of them is characterized by different depth and duration of the flooded period. The plant communities have been analysed by applying Braun-Blanquet’s approach and carrying out 95 phytosociological relevés. The use of multivariate analysis allowed the identification of eight main vegetation types, which have been referred to the classes Isoëto-Juncetea, Littorelletea, Agrostietea stoloniferae and Phragmito-Magnocaricetea. Four new associations are described: Junco tenageiae-Solenopsietum laurentiae ass. nova, Hypochoerido glabrae-Cicendietum filiformis ass. nova, Callitricho brutiae-Ranunculetum ophioglossifolii ass. nova, Callitricho brutiae-Juncetum bulbosi ass. nova, and four new subassociations: Serapio-Isoëtetum histricis Pedrotti 1982 lotetosum angustissimi subass. nova, Solenopsio laurentiae-Juncetum pygmaei V. Silva & Galán de Mera in V. Silva, Galán de Mera & Sérgio 2008 isolepidetosum cernuae subass. nova, Alismo lanceolatae-Gratioletum officinalis Biondi & Bagella 2005 juncetosum conglomerati subass. nova, Callitricho brutiae-Ranunculetum ophioglossifolii ass. nova glycerietosum fluitantis subass. nova. The floristic diversity of the identified plant communities has been analysed, considering species number, species density per m2, Shannon’s and Evenness Indexes. The stand’s features have also been analysed, taking into account the minimum sampling area and the vegetation total cover values, and measuring in the fields pH values and O2 content in the water. With regard to these parameters, the statistical significance of the differences among the detected vegetation types has been tested. The high floristic relevance of these systems is emphasized by the presence of some rare, localized and/or threatened species and Habitats from 92/43/EEC Directive's Annex I. The great coenotic diversity has been interpreted by applying the concept of microgeosigmetum.
ephemeral wetlands, microgeosigmetum, ponds, vegetation, phytosociology, waterlogged soils