1,721,043 research outputs found
Centennial-scale variations of solar activity reflected in the fluctuations of a salt-marsh in southern Italy during the Holocene
No full textMicrobial life on elephant fossil bones from La Polledrara di Cecanibbio. Is it a real threat for their conservation?
No full textThe elephant bones which have been left in situ deserve an outstanding mention, because they make La Polledrara di Cecanibbio the most important elephant site in Italy. Their scientific value requires careful conservation strategies that sometime are in contrast with the exhibition in situ. In fact, the exhibition in situ favors on the one hand the best safeguard of any taphonomic information, as well as a complete fruition of the palaeontological site in its depositional context and major tourist feedbacks; but, on the other hand, it may expose this cultural heritage to the threat of a series of potential pollutant agents, both atmospherical and biological
Holocene drought, deforestation and evergreen vegetation development in the central Mediterranean: a 5500 year record from Lago Alimini Piccolo, Apulia, southeast Italy
No full textPollen 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
An overview of the holocene vegetation history from the central Mediterranean coasts
No full textA review of twenty-six pollen records from coastal areas of central Mediterranean countries (including Malta, Sardinia, Corsica, Italian Peninsula, Sicily, Croatia, and Greece) is presented, in order to describe the general processes characterizing the environmental evolution of this region and to detect the main causes producing landscape change during the last thousands of years. An overview of the main vegetation types shows a rather diverse composition and structure of the vegetational landscape, mostly depending on geomorphic situations, climate conditions, biological processes and human history. This variability makes it impossible to define a pollen stratigraphical scheme valid for the entire area during the last thousands of years. A general and progressive anthropization trend of the vegetational landscape is observed since the Neolithic, evolving with different times and modes from site to site. In many cases human populations adapted their activities to the locally existing natural resources, for example by exploiting native plant taxa (e.g., Olea, Vitis, and Quercus suber) or transforming natural coastal wetlands in saltworks, always determining deep landscape changes and depletion of the native biodiversity. The responses of vegetation to geomorphic processes and climate have generally been different from site to site: in some cases only one sector of the central Mediterranean Basin was involved (e.g. Tyrrhenian expansion of Alnus around 5200 cal. BP), while in other cases extensive geographical processes occurred (e.g. development of coastal wetlands around 7000 cal. BP). This long-term environmental perspective indicates that the current coastal ecosystems of the central Mediterranean Basin represent an ephemeral snap-shot, destined to new, abrupt and dramatic future changes. Thus, palaeoenvironmental studies may prove of fundamental importance in estimating both the environmental instability typical of each geographical context and the degree of vulnerability of coastal ecosystems, so providing suggestions for appropriate conservation actions in coastal environments
Threats for the conservation in situ of the bones exposed at la polledrara di cecanibbio (Rome, Italy).
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