The aim of this research project is to attempt to resolve the detailed climate/vegetation history of the Last Glacial in Southern Italy by providing new palynological data from the promising record of Grotta Romanelli (Apulia). Thanks to a new excavation activity started in 2015 and carried out by Sapienza University of Rome, pollen samples from continuous stratigraphic levels were recovered in order to reconstruct the palaeoenvironmental conditions of the cave during the Late Pleistocene. By studying the fossil pollen remains preserved at the site, I will be able to characterize changes in the local vegetation response to short and warm climatic events known as ¿interstadials¿ and to evidence the millennial-scale climatic variability in the Mediterranean region during this time interval. Since cave palynology is a valuable tool for the reconstruction of past vegetation but the depositional process is still unexplored, I will also focus on understanding the mechanisms involved in the pollen transport and deposition in cave environments and the influence of those factors which impact on the composition of the cave pollen assemblages (i.e. geomorphology, environment, animal/human presence).
This project offers an important advance of knowledge in the palaeoenvironment and palaeoclimatology research field since the number of cave deposits studied for palynological reconstructions in Italy is still limited. By understanding the interaction between environment and climate during the Late Pleistocene, which was dominated by climate and temperature shifts and their effects on Earth¿s life, I¿m also given a chance to better understand the effects of current and future global change in vegetation cover and ecosystem evolution. The evidence from the longest marine and terrestrial pollen sequences in the Mediterranean region suggests significantly reduced moisture supply compared to present-day conditions during the most severe parts of cold stages, based on the high frequency of non-arboreal pollen compared to arboreal pollen (e.g. Allen et al. 2000: Quaternary International 73/74, 91-110). However, at some sites whilst tree populations appear to have been much reduced during Glacial phases compared with Interglacials, even deciduous (and moisture-demand) plant species were sustained through Glacial cycles in local ecological niche (Tzedakis 1993: Nature 364, 437-440). Specifically, the possible identification of interstadial periods from a pollen sequence of the Southern Italy during the Last Glacial can validate the global climatic variability already postulated even from archaeological sites, but whose validity has been questioned (Sanchez Goni 1994: AASP Contribution Series 29, 161-182).
Moreover, the methodological protocol I have planned represents a valuable approach for studying this kind of natural deposits. Given that cave fossil records are mostly the result of environmental, climatic and cultural interactions, in fact, it is essential to understand the complex site formation processes and the post-depositional bias that could have affected the sequences before reconstructing the past vegetation and then inferring the past environmental and climatic conditions. Admittedly, skepticism arises on account of the absence of a solid experimental background for cave palynology (Turner and Hannon 1988: Philosophical Transactions of the Royal Society of London 318, 451-485). The search of general trends on pollen taphonomic processes in cave sites is very difficult to achieve since they are strongly associated to numerous factors, as for example the animal's activities. In this sense the richness of the fossil deposits of Grotta Romanelli constitutes a great advantage: the interdisciplinary research carried out during the last campaigns at the site offers the possibility to compare pollen data with the paleontological and archaeological assemblages, providing useful information about the cave taphonomy. Geological investigations are also essential to reconstruct the formation of the study deposits.