Soil Properties Differentiation of Burned Areas in Pine Forests of Western Transbaikalia

Abstract

Ground fires prevailing in pine forests of Western Transbaikalia have a strong impact on litter and soil properties. The main reason of pine forests high burning of the studied area is the arid climate in the first half of a vegetation season. To study a pyrogenic factor consequences a number of sample plots were laid on the burned areas formed by medium intensity periodic fires and which are at different stages of regenerative succession. Soddy podburs with pyrogenically-transformed profiles are dominated in the soil cover of different-aged burned burned areas. The conducted study revealed that differences in reserves, power and fractional composition of litter, morphological, hydro-physical and physical-chemical indicators of soil upper horizons are the result of fires occurred in different years. Low power and low reserves of litter as well as a high content of fractions of newly fallen pine needles and twigs in its composition are observed for a young burning. High indicators of bulk density, density of solid phase and low values of total porosity, hygroscopic moisture and filtration coefficient are found in the upper pyrogenic soil horizons. It was found that the litter and humus layer of a soil of a young burning are characterized by more alkaline reaction, a high content of exchangeable cations, carbon and low nitrogen content in comparison with those in the soils of a 5year-old burning. Increased content of mobile iron was also noted in illuvial horizons of the soils of a young burning. Characteristics of litter, morphological, hydro-physical and physical-chemical properties are more distinct in the soil of 10-year-old burning.