Vegetation and climate changes during the Miocene climatic optimum and Miocene climatic transition in the northwestern part of Central Paratethys

The study of pollen spectra mirrors the evolution of landscape and climatic changes in the northwestern part of Central Paratethys domain during the regional stages Karpatian-Badenian (Late Burdigalian-Langhian to Early Serravalian; NN4-NN6 biozone). This interval includes the Miocene climatic optimum (MCO) and the Miocene climatic transition (MCT) at 14.8-12.0 Ma. Here we study the pollen record from marine strata in eight wells and sections (Hevlin, Slup, Medlov, Ivan, Lomnice, Zidlochovice, Baden Soos, and Devinska Nova Ves) including a total of 92 samples. The standard pollen diagrams are simultaneously analysed using the Palaeotropical/Arctotertiary concept (P/A), synthesized diagrams, coexistence approach, and a technique allowing to reconstruct diversity of plant functional types in order to unravel climate changes and their impact on the biosphere. Warmest climate conditions supporting a diverse, thermophilous mixed mesophytic forest vegetation with a high proportion of broadleaved evergreen PFTs persisted in the neighbouring continental parts during the Karpatian to Early Badenian (NN4-NN5 biozone) representing the MCO. Evidence for the MTC and subsequent cooling (NN5 and NN6 at ca. 14 Ma) comes from lower percentages of thermophilous and evergreen elements and higher diversity of deciduous PFTs in the ecospectra (Devinska Nova Ves, NN6 biozone). Inferred annual precipitation rates above 800 mm and the almost continuous presence subtropical swamp tree pollen point to the persistence of overall humid climate conditions in the study area. Reconstructed precipitation data and the presence of drought-tolerant plant functional types (PFTs) point to a seasonal climate. The studied records partly show shorter term cyclic changes in climate and plant diversity related to glacial events in the Langhian. Using the proportion of broadleaved evergreen versus broadleaved deciduous tree diversity as indicator for temperature changes, several alternations of warmer and cooler phases are obvious from the record. Moreover, sedimentary facies plays an important role for quality and resolution of terrestrial signals in marine strata.

Automated summary

The study of pollen spectra in the northwestern part of the Central Paratethys domain during the regional stages Karpatian-Badenian provides insight into the evolution of landscape and climatic changes, as well as the impact on the biosphere. The research reveals evidence of the Miocene climatic optimum and transition, as well as changes in plant diversity and climate conditions during the studied periods.