Effects of fire on properties of forest soils: a review

Abstract

Many physical, chemical, mineralogical, and biological soil properties can be affected by forest fires. The effects are chiefly a result of burn severity, which consists of peak temperatures and duration of the fire. Climate, vegetation, and topography of the burnt area control the resilience of the soil system; some fire-induced changes can even be permanent. Low to moderate severity fires, such as most of those prescribed in forest management, promote renovation of the dominant vegetation through elimination of undesired species and transient increase of pH and available nutrients. No irreversible ecosystem change occurs, but the enhancement of hydrophobicity can render the soil less able to soak up water and more prone to erosion. Severe fires, such as wildfires, generally have several negative effects on soil. They cause significant removal of organic matter, deterioration of both structure and porosity, considerable loss of nutrients through volatilisation, ash entrapment in smoke columns, leaching and erosion, and marked alteration of both quantity and specific composition of microbial and soil-dwelling invertebrate communities. However, despite common perceptions, if plants succeed in promptly recolonising the burnt area, the pre-fire level of most properties can be recovered and even enhanced. This work is a review of the up-to-date literature dealing with changes imposed by fires on properties of forest soils. Ecological implications of these changes are described.

Shifts in the abundance and community structure of soil ammonia oxidizers in a wet sclerophyll forest under long-term prescribed burning

“…It has been predicted the frequency and intensity of wildfire would increase under global warming (Bradstock, 2002;Cary, 2002;Westerling et al, 2006). Fire influences the population and species diversity of the aboveground plants (Bond and Van Wilgen, 1996) and belowground soil properties (Certini, 2005) as well as microorganisms (Vázquez et al, 1993). Niboyet et al (2011) found that fires increased soil nitrous oxide emission when interacting with other factors, such as elevated CO 2 , precipitation and N deposition.…”

Index for Characterizing Post-Fire Soil Environments in Temperate Coniferous Forests

“…The mineral soil color is commonly classified as black (semi-combusted organic material), gray or white (ash from organic material), and orange (change in physical structure and lack of organic material) [7,43,48]. Post-fire soil color depends on the amount and type of pre-fire vegetation and surface organic material, their respective moisture contents, and weather (e.g., wind speed, relative humidity, air temperature) during a fire.…”

“…Common soil physical properties influenced by fire include water repellency, structure stability, texture, color, post-fire surface temperatures, and abundance of surface organic material [48] (Table 3). Typically erosion only occurs when organic cover is less than 40-50% after a fire [50][51][52]54].…”

“…For example, when temperatures are between 200-450 ○ C, soil structure stability decreases within a few minutes [48] and the combustion of organics can change particle size distribution [90]. The laterization process (i.e., when weathering causes depletion of soluble substances in soils and rocks) begins when soils are exposed to temperatures exceeding 450 ○ C for at least one hour [90].…”

The effects of fire severity on ectomycorrhizal colonization and morphometric features in Pinus pinaster Ait. seedlings

“…This comes both as a direct result of the high temperatures reached during a forest fire, but also indirectly through changes to soil chemical and physical properties, like a pH increase, enhanced hydrophobicity or changes of available nutrients (Certini, 2005).…”