Recovery of soil nutrient levels after fires
can be fairly slow in some ecosystems,
particularly those with limited nitrogen,
and in semi-arid regions where
decomposition rates are slow. Klopatek
(1987) determined that 35 years after
a wildfire, nitrogen concentrations
beneath pinyon-juniper canopies had not
recovered to levels found in stands that
had not burned in 300 years. In addition,
soils beneath burned stands showed a
twofold increase over unburned stands
in the percent of total nitrogen that was
changed from organic forms such as litter
and humus to more mobile nitrates and
ammonium. While these mobile forms
of nitrogen are more accessible for plant
uptake, they are also more prone to off-site
movement in surface runoff and leaching