Factors Affecting Short Term Nitrogen Availability from Vegetation Fire in the Sierra Nevada
Glass, D. W.. 2006. M.Sc. Thesis. Desert Research Institute, University of Nevada, Reno, NV
Abstract
Forests of the Sierra Nevada have historically experienced fire. Fire suppression has
increased forests fuel loads. Land managers use prescribed as a means to reduce forest
fuel loads. Research has found fire to increase soil NH4+
due to thermal breakdown of
soil organic matter. Factors affecting the magnitude of this pulse have gone unaddressed.
This study looks at antecedent soil properties and fire severity's impact on NH4+
availability following vegetation fire. NH4+
increases were seen in both studies.
Antecedent water content showed a significant influence on NH4+
, NO3-, and mineral N
concentrations in one study. Soil chemical properties did not demonstrate influence over
post fire concentrations of mineral N in either study. Fire severity was seen as an
influential property in both studies. Implications of this study directly influence land
management for ecosystem health and sustainability.