HUMAN IMPACT AND ENVIRONMENTAL CHANGES AS SHOWN BY POLLEN FROM ARCHAEOLOGICAL SITES (HOLOCENE, CENTRAL MEDITERRANEAN)

Most of the biological archives, including pollen, upon which past environmental reconstructions are based, respond to both climate change and human impact. The significance of biological records in regions where changes occurred frequently, and sometimes rapidly, such as the central Mediterranean, may be unclear as different forces may originate their assemblages.The presentation reports pollen analyses from archaeological sites that are clear examples of presence and activities of human groups in their territories. A comparison between pollen data from a mid-late Holocene marine core (RF93-30) and a Middle-Recent Bronze age archaeological site (Terramara di Montale) both with evidence of climate changes and human impact is discussed (Mercuri et al. in press).The regression in the natural forest vegetation, both deciduous and evergreen trees, is visible from the mid-Holocene, and mainly in the late Holocene in RF93-30. An increasing dryness is discernible by the decrease of Fagus since after 5700 cal B.P., and continuing gradually since at least 4780 cal B.P. Later, after an aridity phase at 4500–4000 cal B.P., human impact introduces rapid vegetation changes especially clear in the two records. Particularly, these actions are the fall of silver fir (thinned by the decrease of precipitations and further cut before/at the early Bronze age) and subsequent fall of oaks at around 3600 cal B.P.Xeric environments, represented by Cichorieae, resulted from the continuative human impact, and spread since the Recent Bronze age. Grasslands have continued to be browsed by domestic animals in many districts of the Mediterranean basin for millennia, in southern Italy as well as in central Sahara, and the effects of aridification were enhanced by the (over)-exploitation of lands.