The vegetational history of the northern Apennines, Italy: information from three new sequences and a review of Regional vegetational change

Abstract

Abstract. The results of pollen analysis and radiocarbon dating are presented from three northern Apennine sequences; Lago Padule in northern Tuscany and Lago Pratignano and Ospitale in the Emilia‐Romagnan Apennines. This 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 from Lago Padule is one of the most complete Holocene records known from the northern Apennine region. Lago Pratignano has the deepest sequence of organic sediments (1544 cm) and the fastest rates of sediment accumulation (up to 28 cm per 100 years) providing the highest resolution record for the mid to late Holocene periods in the region. High rates of sedimentation have also occurred at Ospitale where organic sediments are 780 cm deep and began to form at approximately 5500 bp. The record from Lago Padule is compared with Holocene records from two nearby sites and a series of Regional Pollen Assemblage Zones is defined for the eastern area of the northern Apennines. The main features of vegetational change identified are: (i) a‘pioneer’phase of rapid forest development during the early Holocene followed by the establishment of an upper forest belt dominated by Abies, and a belt of mixed deciduous forest at lower altitudes; (ii) the appearance and rapid expansion of Fagus between approximately 5200 bp and 2900 bp forming a mixed Abies‐Fagus association in the upper forest belt; and (iii) the overall reduction of forest cover, and dominance of Fagus in the arboreal vegetation from around 2900 bp. The scheme of Regional PAZs for the eastern area is used as a framework for the review of pollen stratigraphic information and radiocarbon dates from other sites in the northern Apennine 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 four regional PAZs for the Holocene period is shown to be valid for the entire northern Apennine region. The examination of a series of pollen records shows that Fagus appeared earlier in the western than the eastern part of the region during the mid Holocene and became dominant in the northern Apennine forests post 3000 bp. The impact of anthropogenic activity and climatic change on the spread and development of Fagus are discussed. The palynological evidence which is now available from the northern Apennines is compared with information for the region shown in the‘European pollen maps’of Huntley & Birks (1983). This study provides an updated review of the representation of different tree taxa in Holocene pollen records from the northern Apennines and illustrates the role of the northern Apennines as a refugium for trees during the Wurmian Lateglacial.

Vegetation dynamics during the early to mid-Holocene transition in NW Malta, human impact versus climatic forcing

“…As no similar early Holocene delay is observed in the forest expansion of the central and northern Italian Peninsula (e.g. Magri and Sadori 1999;Watson 1996), it seems that the latitudes around 40°N to 43°N mark the northernmost limits of the monsoonal influences on the precipitation patterns in the Mediterranean region Vannière et al 2011). The strengthened subtropical monsoons up to ca.…”

The Holocene at Lac de Creno, Corsica, France: a key site for the whole island

“…The oldest Fagus forests in Corsica are in the Incudine massif (where Fagus still plays a major role today owing to particularly humid conditions ; Gamisans, 1991 Alessio et al, 1986 ;Lago Albano : Lowe et al, 1996). At mountain sites of the Apennines, at an altitude similar to that of Creno, Abies underwent a notable expansion as early as the late-glacial period, for instance at Prato Spilla, 1350 m altitude (Lowe et al, 1996) or Lago Padule, 1187 m altitude (Watson, 1996). Therefore the indigenousness of Fagus and Abies, that is their survival in Corsica throughout the late-glacial, is hardly probable : if it were so, the two species would have reappeared much earlier, as they did in the Italian sites where the same climatic evolution took place.…”

A comparison between different treeline types shows contrasting responses to climate fluctuations

“…Cusna during the early-mid Holocene, but with no evidence of Fagus. A prominent role of Abies alba in the Apennines throughout the Holocene is likely, as suggested by Watson (1996), Vescovi et al (2010a,b), Körner (2012) and Compostella et al (2012); its replacement by Fagus was probably at least in part induced by human activity (Carcaillet & Muller, 2005;Vescovi et al 2010a,b); the marginal role of Picea abies could be the result of ineffective spread due to unfavourable climatic conditions and competition during the Holocene (Ravazzi et al 2006). …”