University of Debrecen, Institute of Earth Sciences
Abstract
Land mosaics have direct and indirect influence on chemical reaction and redox condition of soils.The present paper deals with the relationship between some environmental factors (such as soil andvegetation patterns, micro-relief, water regime, temperature and incident solar radiation) and the pH,Eh of soils and solute iron in a headwater wetland in Transdanubia, Hungary. Measurements havebeen taken in four different patches and along their boundaries: sedge (Carex vulpina, Carex riparia,three patches and two species), horsetail (Equisetum arvense), common nettle (Urtica dioica). Thespatial pattern of the studied parameters are influenced by the water regime, micro-topography,climatic conditions and by direct and indirect effects of vegetation. The indirect effect can be theshading, which has influence on soil temperature and on the incident solar radiation (PAR). Rootrespiration and excretion of organic acids appear as direct effects.. There have been measuredindividual pH and Eh characteristic in the studied patches. Soil Eh, pH and solute iron have shownseasonal dynamics. Higher redox potentials (increasingly oxidative conditions) and higher pH valueswere measured between late autumn and early spring. The increasing physiological activity of plantscauses lower pH and Eh and it leads to higher spatial differences. Although temperature is anessential determining factor for Eh and pH, but our results suggest it rather has indirect effectsthrough plants on wetlands
