The Effects of Slash Pile Burning on Soil and Water Macronutrients

Abstract

Significant effects of slash pile burning on soil chemistry and water quality were observed in forested sites in the eastern Sierra Nevada Mountains of Nevada. Slash piles in upland and meadow sites were instrumented postburn with ceramic cup lysimeters, runoff collectors, and resin stakes (Plant Root Simulator™ probes) along transects from pile centers to unburned areas. Ash and soil samples also were collected along these transects. The pH and concentrations of most nutrients in the soil were highest in the centers of the piles. Larger piles had lower levels of total carbon and total nitrogen in the pile centers (indicative of high burn temperatures and volatilization) compared with smaller piles. There also were differences between meadow and non-meadow systems including higher soil NO3− and lower SO42− amounts in the meadow areas. Soil solution data indicated that peak concentrations exceeded US Environmental Protection Agency water quality standards for both NO2−-N and NO3−-N at all three sites and were 2.5 to 3 times the standards in two sites. Runoff solution peak concentrations also exceeded the standards but only in the meadow site.