Despite the slowing down caused by COVID-19 during the first year of the project, main objectives were achieved. The results were presented at the MedPalynoS 2021 & 2022 (Modena & Paestum), at the European Association of Archaeologists (Kiel) and at the Archaeological Journeys of the Balearic Islands 2022 (Eivissa). In addition, the fellow was interviewed by Balearic Media (Diario de Ibiza and Cala Millor 7) and published a dissemination paper to Focus-UNIMORE. General audience was also reached through a dissemination invited conference at the MAEF Museum (Eivissa).
OLEA-project consisted of 4 main research topics, developed at the Laboratory of Palynology and Palaeobotany (LPP, UNIMORE). We explain the main features and results below:
1) Palaeoenvironmental reconstruction. Pollen analysis from paleo-lagoons (‘off-site’ sequences: Santa Ponça and Trebalúger) confirmed important vegetation changes during the Late Holocene, including the spread of olive trees and other thermophilus taxa. In the case of Santa Ponça, this vegetation change seems to occur about a millennium later than in other sequences from Mallorca and Minorca, this is after 4000 years ago. These discordances between Balearic paleoenvironmental sequences highlight the microregional variability of landscape changes due to different anthropization rhythms, topographic and microclimate conditions. A high interdisciplinary and multiproxy approach was applied to the Santa Ponça sequence including pollen, non-pollen palynomorphs, seda-DNA, sedimentology, fire-history, and radiocarbon dating. This integrated approach will be extended in futures research and publications.
2) Onset and evolution of mosaic landscapes. The integration of both natural and archaeological sequences (“on-site”: Puig de Sa Morisca, Cala Morell and Closos de ca’n Gaià) allowed to further understand the onset of mosaic landscapes during the Bronze Age, with open environments surrounding the archaeological sites. Pollen data from archaeological sites confirmed highly humanized environments during the Bronze Age and Iron Age periods. Differences in pollen assemblages correspond to changes in landscape practices and household activities. Monumental prehistoric houses may be considered permanent places, as they are used for many centuries. Palynology has proven to be an important tool to follow up cultural evolution and climate change/adaptions through time.
3) High-resolution pollen morphology on modern Olea varieties. The pollen morphology of ancient and modern olive tree cultivars from Mallorca was analysed to detect potential morphotypes that could be related to wild vs cultivated olive tree varieties or to specific agronomic varieties of the Balearic Islands. To do so, a new image-analysis software called OLEAtool for morphopalynological research was developed to facilitate the analysis and measurements of Olea pollen. OLEAtool is a macro extension for use with the open-access and freely available image-analysis software, ImageJ.
4) Modern analogues and modelling. Modern sedimentary and moss samples were studied from different Balearic locations in order to further understand the pollen rain and non-pollen palynomorph representation from the main vegetation types of the Balearic Islands. This research furnished novel and key information to understand pollen-vegetation relationships, as well as the correlation of pollen assemblages with environmental and anthropogenic variables. Our work suggested that low pollen percentages of air-borne and high-pollen producing taxa should be interpreted with caution as they likely reflect regional dynamics. To perform such modern analogue study, it was necessary to achieve a high morphological resolution level which was only possible thanks to the LPP pollen reference collection.
