Are Cichorieae an indicator of open habitats and pastoralism in current and past vegetation studies?

Abstract

Cichorieae, one of the six tribes of the sub-family Cichorioideae (Asteraceae), produces a well-recognisable fenestrate pollen type. In the Mediterranean area, the significance of high percentages of Cichorieae pollen from archaeological layers is still questioned. We assessed the presence of Cichorieae as indicators of open habitats and pasturelands in current plant communities by comparing data on vegetation composition with pollen spectra from two Hellenistic sites of Basilicata (southern Italy): Difesa San Biagio in the low valley of the river Bradano and Torre di Satriano in the Lucanian Apennines. We also analysed the pollen morphology bringing to the discrimination of size classes within the fenestrate type of Cichorieae. Pollen spectra from the considered archaeological sites have low forest cover (7% on average); Asteraceae and Poaceae are prevalent; Cichorieae account to ca. 23%; coprophilous fungal spores are varied and present high concentrations. In surface soil samples collected near the sites, Cichorieae pollen is about 12%. In current vegetation types, an increasing abundance of Cichorieae was observed from salt marshes, forests and shrublands to open habitats and grasslands. This is coherent with the actual land cover around the study sites and the findings of the archaeological sample that point to an open landscape dominated by pastures and cultivated fields. Our integrated approach confirmed that today Cichorieae are common in secondary pastures and in some types of primary open habitats of southern Italy: hence, high percentages of this pollen can be considered a good indicator of these habitats even in past environment reconstructions.

Keywords::

• Archaeological sites
• Basilicata
• Mediterranean
• palaeoecology
• phytosociological database
• pollen morphotypes

Acknowledgements

We acknowledge Prof. Massimo Osanna and Dr. Dimitris Roubis (Scuola di Specializzazione in Beni Archeologici di Matera – Università degli Studi della Basilicata) who kindly provided us with archaeological samples and information. Prof. Joseph C. Carter (Director of ICA – University of Texas at Austin) greatly contributed to our comprehension of the archaeological background and history of the study region. Our warmest thanks go to the two anonymous referees for the fruitful comments to the first version of the paper.