Revista Chilena de Historia Natural 76 (4): 529-542, 2003
RESEARCH ARTICLE
Effect of wildfire on soil physical and chemical properties in a Nothofagus glauca
forest, Chile
Effects of a wildfire on soil chemical and physical properties in a Nothofagus glauca
(Phil.) Krasser forest in the Coastal Mountain Range of south-central Chile were investigated. Response of the soil during the
first two years following a wildfire was examined, where data from soil in a burned forest were compared to that in an adjacent,
unburned stand. The effects that wildfire have on soil properties in this highly fragmented ecosystem are not well understood, but
results from this study suggest similar responses to those found in other mediterranean forest systems. Both physical (bulk density,
percent soil moisture, and soil organic matter content) and chemical properties (exchangeable inorganic nitrogen, extractable
phosphorus, exchangeable potassium, and soil pH) were examined, and data presented here suggest that soil properties vary in their
initial response to fire in this ecosystem. Soil organic matter content and soil moisture decreased following fire and remained lower
than values from unburned plots for the duration of the study. Exchangeable potassium increased initially after burning, but values in
burned plots decreased with time and by the end of two years were significantly lower than in unburned soil. In turn, extractable
phosphorus and soil pH both increased immediately following wildfire and values in burned plots remained significantly higher than
unburned plots for the entire measurement period. Exchangeable inorganic nitrogen reached higher levels in soil of burned plots for the
autumn measurements (April 1997 and 1998) and lower values in burned plots for the spring measurements (November 1997 and
1998). Soil bulk density remained unchanged following fire. In general, changes in soil properties following fire were greatest at the 0-5
cm layer and more modest at the 5- 10 cm sampling depth. These changes were related primarily to oxidation of the detrital layer
during fire and concurrent changes in the soil environment following fire (e.g., a reduction in organic matter content of the soil,
decreased soil moisture, and increased soil pH). The results of this study have implications for the productivity and sustainable
management of the native forest remnants in this region.
Key words:
Nothofagus
glauca, soil chemical properties, soil physical properties, wildfire
