CLIMATE CHANGE AND POLYPHASIC SOIL DEVELOPMENT

ABSTRACT

Soils can be defined as four dimensional natural bodies, where the lithosphere, the atmosphere, the hydrosphere and the biosphere are soil – forming factors which operate in geological time. The soil profile reflects the climate change passed during soil – forming process. The majority actual soils are the result of a polyphasic soil development, therefore they involve in their age the climate existing in the Tertiary, especially in the Quaternary, period. Climate change is expected to have several effects on soils. Changes in temperature and precipitation amounts will modify the soil carbon dynamics and physical, chemical and biological weatering. Large area in the SW of Romania are occupied of Paleosol, fossil and relict soil, which indicate climatic changes. The thesis presents a number of soil profiles from this region, with polyphasis development, emphasized by the mineralogical, morphological (B melanic horizon) and chemical analysis. There are, also, two soil profiles with 14C age determinations, such as for a Histosol from the Semenic Mountains and a Chernozems from the village Uivar (Timis county). Another revealing example can be the Paleosols from Vinga and Semlac (Arad county). For some soil profiles from a hilly region, named Dealurile Lipovei (SW of Romania), have been effectuated pollen analysis. Such knowledge will help to prevent irreversible loss of soil function and to prevent loss of organic matter in topsoils. Mineralogical, particle-size distribution, chemical and morphological analysis have been made in order to establish the degree of uniformity or stratification.

Keywords: soil profile polyphasic development, climate change, mineralogical analysis