An overview of Holocene forest pollen flora/vegetation of the Emilia Romagna region - Northern Italy

The aim of this paper is to present a brief overview on the Holocene Forest Pollen Flora/vegetation of the Emialia ROmagna Region, based on the synthesis of the available data, updated to 1999. Data concerned 1342 samples in 156 sites: mean forest spectra per Holocene phases (Preboreal, Boreal, Atlantic, Subboreal, Subatlantic, Recent - the last 50 years) and altitudinal belt (Plain, Hills, Mountains) were calculated as well as some Indexes. The regional Holocene forest pollen flora consisted of 134 taxa belonging to 61 Families and 125 Genera. The main features of the Holocene forest pollen landscape were: 1)forest consistency decreased significantly over time, with a certain revival in the Recent; 2)in the Plain, Pinus dominated the Preboreal and broadleaves suddenly spread from the Boreal onward; 3)mixed broadleaf woods always prevailed in the Hills, with refuge stations for castanea and Juglans in the Preboreal-Boreal; 4)conifers were prevalent in the mountains from the Preboreal to the Atlantic; 5)in the Atlantic, the landscape was the most monotonous, with Abies, Pinus, Quercus, Tilia, Alnus, Corylus spread throughout the Region; 6)Abies was notably spread throughout the Region from the Subboreal; 7)hygrophilous woods were very widespread and abundant from the Atlantic to the Subatlantic; 8)Abies and Fagus maintained some stations in the Plain even up to the Subatlantic; 9)the mixed Oak wood continuously renewed throughout the Holocene: Tilia was abundant in the Boral-Atlantic, carpinus emerged at different times in each altitudinal belt, Ulmus in the Subboreal, Fraxinus and especially Ostrya in the Recent; 10)humans progressively influenced the vegetal landscape. This influence was increasingly suggested from Preboreal to the Atlantic, more visible in the Subboreal and even more evident in the Subatlantic-Recent. The human influence testified by woody pollen concerned mainly 4 types of activity: a)forest clearance; b)protection, care, precultivation-cultivation; c)crowding of the pollen flora; d)"urban afforestation"; 11)the data of the Plain suggested that the cultural vegetal landscape spread from the settlements: hmans settled in open areas; preferred to settle near woods of deciduous broadleaves rather than conifers; grew useful native trees in their settlement; possibly used Tilia, Ulmus and Acer for animal fodder, since the Subboreal have had the habit of polluting the flora by growing "Exotic" trees. This habit has exploded in the Recent and will be a useful chronological marker for the end of the second millennium AD, in the future.