The Pliocene macro- and microflora of lacustrine sediments from Meleto (Valdarno, N. Italy) and its ecological, palaeobiogeographical and climatic interpretation

The exceptionally well preserved flora from the Neogene sediments of Meleto, in the Valdamo region (Italy), comprises numerous taxa of leaves (58 taxa), diaspores (39 taxa) as well as pollen and spores (63 taxa). The plant taxa, many of which have been tentatively correlated with extant taxa, have been assigned to different ecological habitats representing vegetational units surrounding a lake. Palaeobiogeographically, the flora is dominated by arctotertiary elements, but also contains palaeotropical elements, some representing “old” taxa (e.g. Trigonobalanopsis rhamnoides (Rossmässler, 1840) Kvaček et Walther, 1988, Sinomenium cantalense (Reid, 1920) Dorofeev 1963). By using the climatic requirements of the nearest living relatives, a Cfa-climate has been inferred for the Pliocene Valdarno region. The carpoflora and the leaf assemblage closely resemble Upper Miocene and Lower Pliocene floras of Southern and Middle Europe in contrast to the published Late Pliocene to Pleistocene ages. The anomaly may be interpreted by a persistence of species characteristic for Miocene floras in the area. Altogether, the Meleto flora provides a new and detailed insight into the Neogene vegetation of the Valdarno region and significantly contributes to the understanding of floral development in the Mediterranean area.