Impacts of aridification on soils and vegetation in sand region of the Hungary

Abstract

Sand areas are regarded most sensitive to changes in water budget brought about by the aridification of climate. In the paper the sand region of the Kishunság National Park is studied for the sensitivity of soil and vegetation cover to drought. The quickest response to climate changes is expected to be manifested in the hydrological regime, followed by alterations in the composition of vegetation cover, inducing, with some time lag, modified soil processes. The list of the non-arborous flora of the test area was analyzed using a range of ecological indices partly developed by Hungarian ecologists. Soil profiles were studied to find traces of a modified water regime and element migration induced by aridification. The high shares of submediterranean and other xerophilous or drought-tolerant species show that vegetation has already adapted to dry conditions, which has been a concomitant of regional climate. There are two ways of soil formation in the sand region: on dune summits humification to the effect of pioneer associations and in inter-dune hollows the accumulation of fine deposits and soil moisture content are the principal controlling factors. Reduced infiltration and capillary rise endanger ex-sting water regimes, A positive impact of aridification is local dealkalinisation of sodic soils.