Cs. Watson, THE VEGETATIONAL HISTORY OF THE NORTHERN APENNINES, ITALY - INFORMATION FROM 3 NEW SEQUENCES AND A REVIEW OF REGIONAL VEGETATIONAL CHANGE, Journal of biogeography, 23(6), 1996, pp. 805-841
The results of pollen analysis and radiocarbon dating are presented fr
om three northern Apennine sequences; Lago Padule in northern Tuscany
and Lago Pratignano and Ospitale in the Emilia-Romagnan Apennines. Thi
s is the first detailed pollen stratigraphic information from sites in
Emilia-Romagna and north Tuscany and extends eastwards the area from
which information on vegetational history is available. The sequence f
rom Lago Padule is one of the most complete Holocene records known fro
m the northern Apennine region. Lago Pratignano has the deepest sequen
ce of organic sediments (1544 cm) and the fastest rates of sediment ac
cumulation (up to 28 cm per 100 years) providing the highest resolutio
n record for the mid to late Holocene periods in the region. High rate
s of sedimentation have also occurred at Ospitale where organic sedime
nts are 780 cm deep and began to form at approximately 5500 BP. The re
cord from Lago Padule is compared with Holocene records from two nearb
y sites and a series of Regional Pollen Assemblage Zones is defined fo
r the eastern area of the northern Apennines. The main features of veg
etational change identified are: (i) a 'pioneer' phase of rapid forest
development during the early Holocene followed by the establishment o
f an upper forest belt dominated by Abies, and a belt of mixed deciduo
us forest at lower altitudes; (ii) the appearance and rapid expansion
of Fagus between approximately 5200 BP and 2900 BP forming a mixed Abi
es-Fagus association in the upper forest belt; and (iii) the overall r
eduction of forest cover, and dominance of Fagus in the arboreal veget
ation from around 2900 sp. The scheme of Regional PAZs for the eastern
area is used as a framework for the review of pollen stratigraphic in
formation and radiocarbon dates from other sites in the northern Apenn
ine region. Characteristics of pollen records which can be identified
in sequences from across the region are identified and the chronology
of similar changes in pollen stratigraphy is examined. The scheme of f
our regional PAZs for the Holocene period is shown to be valid for the
entire northern Apennine region. The examination of a series of polle
n records shows that Fagus appeared earlier in the western than the ea
stern part of the region during the mid Holocene and became dominant i
n the northern Apennine forests post 3000 sp. The impact of anthropoge
nic activity and climatic change on the spread and development of Fagu
s are discussed. The palynological evidence which is now available fro
m the northern Apennines is compared with information for the region s
hown in the 'European pollen maps' of Huntley & Birks (1983). This stu
dy provides an updated review of the representation of different tree
taxa in Holocene pollen records from the northern Apennines and illust
rates the role of the northern Apennines as a refugium for trees durin
g the Wurmian Lateglacial.