تاثير اقليم بر خصوصيات مورفولوژيكي و كاني شناسي بعضي از خاك هاي تشكيل شده از مواد مادري آهكي در مناطق جنگلي شمال ايران

Effects of climate on morphological and clay mineralogical characteristics of some soils developed in calcareous parent material in forestry regions of norhtern Iran

In order to evaluate the influence of temperature and precipitation on formation and development of soil in forestry regions of Elburz Mountains northern Iran, three different climatic conditions namely udic-thermic, xeric-mesic, and udic-mesic were diagnosed. In each climate one unit of mountain physiography with parential calcarious material were selected. Then, to determine macro-and microorphological, physico-chemical and clay mineralogy characterstics, the necessary soil profiles were also considered in various situation and direction. Field and laboratory studies showed that udic-mesic area contains deep soils with mollic epipedon and clay cutans (argillan) accumulated on the walls of voids. With increasing soil depth, the amount of clay cutans was also increased. Relative occurrence of clay minerals was montmorillonite, illite, vermiculite, chlorite and kaolinite, respectiveiy. ʹ.n xeric-mesic areas the solum was thick and organic matter of surface horizon also were low. Only a few amount of calcite in form of microcristals (calcite) have been accumulated on the walls of voids. The relative occurrence of clay minerals was illite, chlorite and vermiculite, respectively. However, in udic-thermic areas, due to high rainfall and temperature, calcite were leached and clay were moved downward. Clay cutans (ferri-argillan) were observed on the walls of voids from shallow depth which were maximized in depth of 78 cm. Relative occurrence of clay minerals were illite, vermiculite, montmorillonite, chlorite and kaolinite, respectively. Depth increasing enhances the relatic amount of montnorillonite.