03 - Studia Geobotanica - An International Journal - Vol. 3 (1983)

CAREX VULPINOIDEA MICHX. ADVENTITIOUS IN THE BELLUNO PROVINCE. This American species has been found for the first time in Italy near Belluno.

PASTURES OF THE VETTE DI FELTRE. This study deals with the floristic composition of the grasslands in the Vette di Feltre (SW-Dolomites, Prov. Belluno, Italy) and with the potential of this territory for grazing. The vegetation types of economic interest above timberline are: Seslerio-Caricetum sempervirentis, Nardetum and Rumicetum alpini. These have heen mapped and the area covered by each association has been calculated. The yearly phytomass production was estimated with field measurements. On the basis of the floristic composition it is possible to calculate the fodder production in the area and consequently the optimal grazing pressure. Intensive grazing in the last centuries produced huge changes in the vegetation of the area.

MICROCLIMATIC INVESTIGATIONS IN THE ALPINE VEGETATION OF THE VETTE DI FELTRE. Synecological studies of the vegetation have been carried out in the glacial circus Busa delle Vette at about 2,000m (Vette di Feltre, Prov. Belluno. Italy), on limestone. The microclimate of the grasslands association (Seslerio-Caricetum semperuirentis and Nardetum) is mesic, whereas the pioneer Adenostyli-Heracleetum, colonizing the scree slopes, has warmer and drier conditions. On the contrary the Adenostyles glabra-association and the Rumicetum alpini are confined to more humid sites. The pedological study confirms such relations. The earliest stage of the pedogenetical evolution with (A)-C profile of the Adenostyli-Heracleetum develops a soil characterized by the presence of a mollic epipedon under the Seslerio-Caricetum sempervirentis. Intensification of the pedogenetic processes leads to the formation of an illuvial horizon in the Nardetum-soils. Further developmental stages with peculiar features, can be identified in the Rumex alpinus- and Adenostyles glabra - associations.