Leaching of soil nutrients in Pinus resinosa after simulated fire.

Abstract

Forest fire is a natural disturbance that effects the nutrient content of soils. Distribution of these nutrients in the soil profile can determine the availability of these nutrients to plants. This is important to the regeneration and growth of ecosystems after a fire. We reconstructed the soil profile in columns and simulated the processes of forest fire and post-fire leaching of nutrients. There were control soil columns with unburned O horizon and experimental columns with burned O horizon. With both sets of columns, three held only O horizon, three held O and E horizons, and three held O, E, and B horizons. Using colorimetry and conductivity, we analyzed leachate from the soil columns and were able to determine where nitrate, ammonium, phosphate, and dissolved cations are retained in the soil profile. We were also able to compare nutrient movement between soil having both a burned and unburned organic layer. We found that each nutrient studied followed an individual trend, and that the E horizon acted not only as a zone of leaching but was also able to retain nutrients.