Soil nitrogen changes associated with slash pile burning in pinyon-juniper woodlands

A combination of a time sequence and an experimental approach, both with repeated measurements, was used to determine the effects of slash pile burning in a pinyon-juniper woodland. Results showed that burning caused mediate increases (approximately 50-fold) in soil ammonium concentrations. Nitrate concentrations were not immediately affected; however, by one year after burning, nitrate concentrations were approximately 20 times higher where piles had been burned than in unburned controls. These increases in inorganic nitrogen disappeared by year 5 after burning. Such a combination of repeated measures with both a time sequence approach and an experimental approach offer a procedure for rapidly estimating long-term response functions in forest research.