This paper presents an event stratigraphy based on data documenting lake-level changes as well as volcanic eruptions over the period 4500—3500 cal. BP from sediment sequences of Lakes Accesa in Tuscany (north-central Italy) and Maliq (Albania) in the central Mediterranean. The available data make it possible to recognise a tripartite climatic oscillation between c. 4300—3800 cal. BP. A phase characterised by drier conditions at c. 4100—3950 cal. BP appears to have been bracketed by two phases marked by wetter conditions and dated to c. 4300—4100 and 3950—3850 cal. BP, respectively. The deposition of the Avellino tephra occurred during the first humid phase, slightly before 4300 cal. BP, and that of an interplinian tephra AP2-AP4 (or Pr1) around 4050 cal. BP during the dry intermediate phase. This dry median episode may be related to the so-called ‘4.2 ka event’ observed in tropical areas as well as in northwestern Italy. A comparison of the Accesa lake-level record with palaeoclimatic terrestrial and marine records suggests that this complex climatic oscillation around 4300—3800 cal. BP affected the central and western Mediterranean area. The key position of the 4300—3800 cal. BP climatic oscillation at a crucial transition from mid to late Holocene in the Mediterranean and tropical areas, deserves major consideration in further investigations.

A high-resolution pollen record from Lago Trifoglietti in Calabria (southern Italy) provides new insights into the paleoenvironmental and palaeoclimatic changes which characterise the Holocene period in the southern Italy. The chronology is based on 11 AMS radiocarbon dates from terrestrial organic material. The Holocene history of the vegetation cover shows the persistence of an important and relatively stable Fagus forest present over that entire period, offering a rare example of a beech woodstand able to withstand climate changes for more than 11 000 yr. Probably in relation with early Holocene dry climate conditions which affected southern Italy, the Trifoglietti pollen record supports a southward delay in thermophyllous forest expansion dated to ca. 13 500 cal BP at Monticchio, ca. 11 000 cal BP at Trifoglietti, and finally ca. 9800 cal BP in Sicily. Regarding the human impact history, the Trifoglietti pollen record shows only poor imprints of agricultural activities and anthopogenic indicators, apart from those indicating pastoralism activities beneath forest cover. The selective exploitation of Abies appears to have been the strongest human impact on the Trifoglietti surroundings. On the basis of (1) a specific ratio between hygrophilous and terrestrial taxa, and (2) the Modern Analogue Technique, the pollen data collected at Lago Trifoglietti led to the establishment of two palaeoclimatic records tracing changes in (1) lake depth and (2) annual precipitation. On a millennial scale, these records give evidence of increasing moisture from ca. 11 000 to ca. 9400 cal BP and maximum humidity from ca. 9400 to ca. 6200 cal BP, prior to a general trend towards the drier climate conditions that have prevailed up to the present. In addition, several successive centennial-scale oscillations appear to have punctuated the entire Holocene. The identification of a cold dry event around 11 300 cal BP, responsible for a marked decline in timberline altitude and possibly equivalent to the PBO, remains to be confirmed by further investigations verifying both chronology and magnitude. Two cold and possibly drier Boreal oscillations developed at ca. 9800 and 9200 cal BP. At Trifoglietti, the 8.2 kyr event corresponds to the onset of cooler and drier climatic conditions which persisted until ca. 7500 cal BP. Finally, the second half of the Holocene was characterised by dry phases at ca. 6100–5200, 4400–3500, and 2500–1800 cal BP, alternating with more humid phases at ca. 5200–4400 and ca. 3500–2500 cal BP. Considered as a whole, these millennial-scale trends and centennial-scale climatic oscillations support contrasting patterns of palaeohydrological changes recognised between the north- and south-central Mediterranean.