Middle Miocene vegetation of the Vallès-Penedès Basin (NE Iberian Peninsula), as inferred from fossil pollen records: State of the art and future prospects

Abstract

In the Mediterranean region, the study of fossil pollen has provided a comprehensive spatiotemporal picture of the Neogene flora and vegetation. The NW Mediterranean sector is a reference area for the study of vertebrate evolution, especially during the Middle Miocene, but paleofloristic and paleovegetational patterns are much less known, which hinders placing faunal evolution in the appropriate paleoenvironmental context. Here, the existing palynological evidence for this area is reviewed to identify the main knowledge gaps and to devise possible future developments. The few palynological records available have provided quantitative paleotemperature and paleoprecipitation estimates, along with general paleovegetation reconstructions, using a modern-analog (MA) approach. The suitability of this method is discussed here and the use of a complementary fossil-community (FC) approach, which has been demonstrated to be useful in other areas and time intervals, is proposed and illustrated using the available raw data. The MA approach is consistent with the available paleoclimatic evidence but special care should be placed on the reliability of overly precise quantitative estimates and the latent danger of circularity when analyzing the biotic responses to climatic changes. The FC approach is considered to be more suitable for reconstructing past communities because it requires less unwarranted assumptions. Additional fieldwork efforts are needed in the search for new pollen records, with an emphasis on more complete ecosystem reconstructions using both floral and faunal evidence.