Vegetation dynamics during the early to mid-Holocene ... - IMEP

Veget Hist Archaeobotboth warm temperatures with seasonal drying and alsoincreased input of minerogenic sediments via fluvial systems(e.g. Carrión and Navarro 2002). In the Black Sea, it has beenfound in the late Holocene layers, while in the early Holocenebrackish waters of the same basin it has not been found(Mudie et al. 2011). This may suggest a link with increasedanthropogenic activities in the Black Sea drainage basin. Itsincrease in the Burmarrad palaeo-estuarine environmentmay thus be better interpreted as being related to a slightincrease in soil erosion due to human activities in accordancewith other anthropogenic indicators.ConclusionsThe main trends of vegetation change in NW Malta duringthe early to mid-Holocene transition were similar to otherregional vegetation records from the south-central Mediterraneanregion, especially those of coastal Sicily characterizedby the transformation of a steppe-like vegetation/garrigue into a dense shrubland/maquis dominated byevergreen Pistacia. Differences in the vegetation dynamicsseem to be mostly linked to the different phytogeographicaland floristic contexts of Malta in relation to neighboringareas. The ca. 2,000-year pollen record presented in thisstudy shows that the potential natural vegetation of theMaltese islands in the absence of human pressure is notnecessarily an evergreen oak forest dominated by Quercusilex, but can be a Mediterranean evergreen shrubland orsmall woodland comprising Pistacia cf. lentiscus and mostprobably other insect-pollinated trees and shrubs not representedin the pollen assemblages (e.g. Ceratonia siliqua).Malta and Sicily are located at a key climatic point in thecentral Mediterranean because the Holocene climatic historyshows different palaeohydrological patterns, to the north andsouth of their latitudinal position. Their different vegetationand hydrological dynamics may reflect a stronger effect ofthe strengthened subtropical monsoon systems during periodsof the Northern Hemisphere boreal solar insolationmaxima. Although the traces of human activities in thestudied area are evident from the beginning of the diagram atca. 7350 cal. B.P./5350 B.C., human presence has becomemore evident since the beginning of the Temple culturalphase at ca. 6050 cal. B.P./4100 B.C. through a conspicuousreduction in tree pollen and increasing values of anthropogenicpollen indicators of overgrazing and soil erosion. Aswith coastal Sicily, we suggest that the early- to mid-Holocenevegetation transformation was mainly controlled by aregional climatic change that occurred in a landscape onlyslightly impacted by human activities.Acknowledgments This study was supported by the PALEOMEDproject (ANR 09-BLAN-0323-204 01) financed by the FrenchNational Research Agency. The first author wishes to thank LaurentLondeix, Maria Sanchez Goñi, Jean-Louis Turon, and FrédériqueEynaud from EPOC, for their hospitality and valuable advice ondinoflagellate identification and scientific discussions during hisresearch stay at the University of Bordeaux in January 2011. 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