Post-fire soil nutrient dynamics in a tropical dry deciduous forest of Western Ghats, India.

Background: The effect of forest fire on soil is complex and relatively less understood than its above ground effect. Understanding the effect of fire on forest soils can allow improving management of valuable forest ecosystems as adequate and proper information is very important for efficient management. We have studied the recovery of soil properties after fire, using a chronosequence approach (two, five and fifteen years after fire and control). Soil samples were collected from each plot of four fire patches (B0, B2, B5 & B15) from three different depths viz. 0-10 (Top), 10-20 (Middle), and 20-30 cm (Bottom).Results: Soil organic carbon was lower than unburned plots after the fire and could not recover to the level of unburned plot (B0) even in 15 years. Total N, available P, and extractable K were lower 2-years and 5-years after the fire but are higher than unburned plot after 15-years. Available nitrogen (NO₃⁻ and NH₄⁺) remain unchanged or higher than B0 in burned patches. Soil pH, Bulk Density, Water Holding Capacity, and Electrical Conductivity was lower initially after the fire. Forest fires have affected soil properties considerably. The response of soil properties varied with years after fire and soil depth.Conclusion: Forest fires occur very frequently in the study area. Significant quantities of carbon and total nitrogen are lost to the atmosphere by burning of litter, duff, and soil OM. Because nitrogen is one of the most important soil nutrients, the recapture of N lost by volatilization during a fire must receive special attention. Long-term studies are required to better understand the recovery of soil nitrogen. [ABSTRACT FROM AUTHOR]