Dynamic of Soil Gases Flux in Relation to Pit and Mound Microtopography in a Broad-leaved Forest

The aim of this research was to study dynamics of soil CO2، CH4 and N2O fluxes related to variability of some soil characteristics in different ages of pit and mounds i. e. the microtopography created by uprooted trees. For this purpose، the control parcel of Lalis district located in Mazandaran province was studied and twenty four uprooted trees from beech species were found. Pit and mound age was considered equal to the dead tree age. Based on this assumption، six، seven، five، and six dead trees belonged to young، medium، adult، and old pit and mounds، respectively. Soil samples were taken at 0-15 cm depth from top of the mound، pit bottom، and closed canopy micro sites. Some of soil physico-chemical and biological characteristics (texture، water content، organic carbon، total nitrogen، abundance and biomass of earthworms) were measured at the laboratory. Results indicated that pits (0. 55 mg CO2، 0. 10 mg N2O and -0. 32 mg CH4 m-2 day-1) emitted more CO2 and N2O and had less uptake of CH4 compared to mounds (0. 19 mg CO2، - 0. 03 mg N2O and -0. 52 mg CH4 m-2 day-1). Potential of CO2 and N2O emissions and CH4 uptake are increased by pit and mounds with time. The results of this research can be considered in evaluation and management of forest ecosystems blown down by wind.