ALKALIZATION PROCESS AND HISTORY OF ALKALINE STEPPES IN HUNGARY (CENTRAL EUROPE)

Sodification can be found on about 15 percent of the Great Hungarian Plain. The Great Hungarian Plain has got the size of 100.000 square kilometres and lays in the central part of the Carpathian Basin. One of the most and largest sodificated area developed on the Hortobágy region, which is included in Hortobágy National Park. The quartermalacological and paleobotanical results show that the grassland and open land vegetation dominated in the investigated area during Last Pleistocene and Holocene. The palynological data suggest that several alkaline steppe elements have been present since 35-40 thousand years ago. The greater part of Hortobágy was an alluvial plain at the end of the Pleistocene. The mineralogical, quarterpaleontological data prove unambiguously that on Hortobágy the sodification and the formation of sodic puszta took place far before history, productive agriculture and animal breeder cultures. Of course sodification happened not on the whole area of Hortobágy but on the southern, southeastern and eastern sides from where by the dominance of animal breeding and the development of river-control it spread to the central and the northwetern, wetern areas. So the anthropogenic effect made the sodification spread from the ancient patches to those areas that formerly were not periodically water supplied or were covered with water during a greater part of the year.