DOES SOIL CHANGE CAUSE VEGETATION CHANGE OR VICE VERSA? A TEMPORAL PERSPECTIVE FROM HUNGARY

Abstract

The long-term relationship between major climatic change, vegetation change, and soil development is complex and poorly understood. In northeastern Hungary, for example, geochemical and pollen studies from a lake sedimentary sequence indicate that in the early postglacial, vegetation changed from a coniferous to deciduous forest, and soils from a podzol to brown earth. But which changed first? Did climatic warming result in a transformation from one soil type to another, which in turn resulted in a change in forest composition, or did the vegetation change first and subsequently alter the soil? How long did these soil transformation processes take? And what mechanisms were involved in the development of a brown-earth soil from a podzol? This paper presents the results of a study addressing some of these questions using palaeoecological analyses of a sedimentary sequence from lake Kis-Mohos To in northeastern Hungary. A proposed model for the process by which a podzol becomes transformed into a brown earth is presented, and possible triggering mechanisms are discussed. Results suggest that in northeastern Hungary the postglacial increase in deciduous populations was not consequent on soil type; rather, deciduous trees increased on podzolic soils, and this increase was one of the triggering mechanisms responsible for the development of brown-earth soils.