Explain the mechanisms of gas exchange in soils. Explain the difference between aerobic and anaerobic respiration. Describe the relationship between aeration and oxidation-reduction processes in soil. Describe the factors that influence soil temperature. Describe the mechanisms of heat transfer in soil.
Mass flow can occur into the soil in response to water uptake by plants.
Water uptake empties pores resulting in the movement of air into the pores. Also occurs when water fills pores the air must be displaced. Occurs due to diurnal temperature differences between the soil surface and the bulk atmos. Only important in the top few inches of soil. Some wetlands may be flooded daily and some may never be flooded.