Holocene drought, deforestation and evergreen vegetation development in the central Mediterranean: a 5500 year record from Lago Alimini Piccolo, Apulia, southeast Italy

Abstract

Pollen analysis from Lago Alimini Piccolo provides the first record of mid- and late-Holocene vegetation history of a coastal area in the easternmost region of southern Italy (Salento-Peninsula). Terrestrial pollen taxa document expansions and declines of the Mediterranean forest, in relation to human activity and climate changes. Between 5200 and 4350 cal. BP a dense evergreen oak forest dominated the landscape; then a distinct opening of the forest is recorded (4350-3900 cal. BP). A new forest expansion (3900-2100 cal. BP) is characterized by an increase of Olea and evergreen shrubs, indicating a development of mediterranean climate conditions and increasing human disturbance. The Roman occupation period (2100-1500 cal. BP) shows a significant opening of the forest, expansion of halophytes and modest values of Olea. After 1500 cal. BP human impact causes a further decrease of the natural woodland in favour of an extraordinary expansion of Olea. The vegetation development at Lago Alimini Piccolo, interpreted in the light of other pollen records, provides new insights into climate evolution and evergreen vegetation development in the central Mediterranean region: (1) a temporary mid-Holocene deforestation at 4000 cal. BP involving many Italian sites south of 43 degrees N was possibly caused by drought associated with an expansion or northward displacement of the North African high pressure zone; (2) the Bronze Age increase of Olea, coupled with a widespread increase of Mediterranean shrubs, suggests management of wild trees, while the beginning of intensive cultivation of olive trees is only found after the Roman time

Pollen-based reconstruction of Holocene vegetation and climate in southern Italy: the case of Lago Trifoglietti

“…9f). Such dry climate oscillation around 4400-4000 cal BP has been recognised from previous studies in the central and eastern Mediterranean (Drysdale et al, 2006;Di Rita and Magri, 2009;Noti et al, 2009;Tinner et al, 2009;Finné et al, 2011;Roberts et al, 2011b). At higher latitudes, it coincided with the beginning of the Neoglacial (Giraudi et al, 2011;Zanchetta et al, 2012;Vannière et al, 2012), marked by a glacier readvance in the Gran Sasso massif in central Italy.…”

“…Southern Italy is a place where climate and human influences are superimposed, with (1) orbitally induced long-term climate changes and possible short-term time-transgressive climate oscillations developing according to latitude (Di Rita and Magri, 2009), and (2) major cultural changes such as the Neolithic expansion in southeastern Italy between 9000 and 8000 cal BP and in south-western Italy between 8000 and (Ariztegui et al, 2000 and references therein), Lago Battaglia (Caroli and Caldara, 2007), Lago Alimini Piccolo (Di Rita and Magri, 2009), Lago Grande di Monticchio (Allen et al, 2002), C106 (Di Donato et al, 2008), Grotta di Latronico (Colonese et al, 2010), Canolo Nuovo (Schneider, 1985), Lago di Pergusa (Sadori and Narcisi, 2001), Biviere di Gela (Noti et al, 2009), Grotta di Carburangeli (Frisia et al, 2006), Gorgo Basso ), Lago Preola (Magny et al, 2011b;Calò et al, 2012), AD91-17 (Sangiorgi et al, 2003), BS7938 (Sbaffi et al, 2004), MD90-917 (Siani et al, 2012).…”

The last 7 millennia of vegetation and climate changes at Lago di Pergusa (central Sicily, Italy)

“…The stalagmite stopped to grow after 2800 cal BP, suggesting enhanced dryness. An increase of Olea pollen soon before 3000 cal BP is found in Adriatic cores and in Italian continental ones (CombourieuNebout et al, 2013;Di Rita and Magri, 2009;Mercuri et al, 2012Mercuri et al, , 2013, indicating that this was a rather general change in the Mediterranean landscape. The exploitation of olives in Greece during the Bronze Age has been documented by both macroremains and pollen (Kouli, 2012).…”

Contrasting patterns of climatic changes during the Holocene across the Italian Peninsula reconstructed from pollen data

“…In the southeastern Aegean Sea, the H index records a humid phase between 5400 and 4300 kyr that coincides with the deposition of a distinct sapropel-like layer and that is interrupted at ∼ 4.2 cal kyr BP (Triantaphyllou et al, 2009b). Additionally, some Italian sites south of 43 • N have shown temporary midHolocene deforestation at 4000 cal yr BP that may have been caused by drought (Di Rita and Magri, 2009). Magny et al (2009) recognize a complex tripartite climatic oscillation between ca.…”