Folia Historico-Naturalia Musei Matraensis - A Mátra Múzeum Természetrajzi Közleményei 17. (1992)
Bužek, Č.–László, J.: Contribution to the Upper Pannonian flora from Visonta, northern Hungary
Marginal riparian including periodically flooded forest is usually present and seems to be even domlnanted in the assemblages. This vegetation type was probably widespread in the region of the brown-coal basin at Visonta. In the tree zone of this unit Alnus sp. (cone remains, Isolated cone - scales, catkin and leaf fragments) is dominanting, associated with such taxa as Carpinus sp. ex gr. betulus, Salix sp., Cornus cf. gorbunovil, Liriodendron sp. and Pterocarya sp. In the shrub zone Sambucus pulchella, Actlnidia faveolata and Ilex sp. occured, with Carex sp., Ranunculus sp. and Selaginella sp . in the herbaceous undergrowth. Streamside vegetation of this community is represented by herbs as Decodon gibbosus and Lycopus cf. europaeus. Representatives of the aquatic vegetation are regularly present in the studied assemblages. Beside surface floating types as Nympheea szaferi, Pseudoeuryale cf. dravertii, Nuphar pelfalvyi, Salvinia cf. intermedia and Potamogeton sp. div., such emerged water plant as Stratiotes tuberculatus and submerged type as Ceratophyllum dubium also occured. Extinct Hartziella miocenica was probably subaquatic plant and can be associated with the last zone of the water vegetation. This autochthonous flora is slightly Influenced by the allochthonous elements transported by the streams or rivers into the basin. They are represented by cupules of Fagus decurrens and most probably by the remains identified as cf. Stuartla beckerena and cf. Prunus sp. which might occupy wider periphery of the basin. In general, some members of Pinaceae in the assemblages may be also considered as en allochthonous element. However, the ecology of Pinaceae is rather varied. Abies is more often a component of the beach forests on moist and fertile soils. Tsuga apparently represents the seme moist forest vegetation. Compared with it, Picea usually grows on somewhat drier soils of elevated sites. Likewise the representatives of section Pinus, but some taxa of section Strobus may also grow in the moist communities. CHARACTER OF CLIMATE ANO STRATIGRAPHICAL RELATIONS The materials from washings are characterized by the presence of the large number of swampy and aquatic plants. Regarding the climate only little can usually be deduced from such Indifferent plants which are growing in the rather stable conditions of swamps. In spite of this fact, Salvinia is already represented by the evolutionarily younger section of genus, and the Nymphaeaceae Include new types which then partly became extinct in the Pliocene. These changes may reflect local ecological factors or some climatic variation during the Upper Miocene and Pliocene time. However, such widespread Upper Miocene plant as Caldesla continuously persists in the Pliocene of Central Europe. In this regard, the occurrence of Fagus attracted our attention for its clear record in a certain stratigraphical level of the Pannonian s.l. (e.g. in the uppermost Dacián to the lowermost Romanian) In this region where it was documented from the Pannonian and Pontian only on the basis of leaves. The cupules are well known from the Middle-Upper Miocene and Pliocene (Brunssumian and Reuverian) localities of Central and West Europe. Besides, they were recently described from the uppermost pert of the "Indener Schichten" of the open mines Hambech and Fortuna in West Europe (Van der BURGH 19B7). This sections of the sedimentary complex are most probably of Messinian age (Van der Burgh 198B). In the Hambech mine, further cupules of Fagus were found in the levels which are probably younger than Brunssumian in age (Van der BURGH 1983). Although the Messlnien was correlated with the Pontian of Paratethys, the carpologlcal floras from Visonta seem to be generally similar to those of the Hambach mined The composition and climatic charecter of vegetation of these localities indicate some warm periods that apparently cover both time intervals of the Upper Miocene and Pliocene which are characterized by the presence of Fagus. 62
