Fire Effects

Finestrat, Alicante, Spain

Soil affected by a forest fire 7 months ago, first pines (Pinus halepensis) start growing

Finestrat, Alicante, Spain

Topsoil affected by high fire severity. The picture was taken 7 months after the fire. Organic layer and soil organic matter was affected by combustion (more info related, e.g.: Mataix-Solera et al., Int J Wildland Fire 2002)

Bocairent Valencia 2010

Ash colour as indicative of fire severity. Dark colours indicate low degree of combustion –low severity- white ash is indicative of high degree of combustion, high severity (more info: Bodí et al., Earth Sci Rev, 2014)

Soil water repellency

Extremely water repellent forest soil sample after be heated at 250ºC under lab conditions. Water repellency was developed as consequence of the combustion of organic compounds and their condensation on the surface of aggregates and mineral particles (more info: Arcenegui et al., Eur J Soil Sci, 2007)

Montgó, Javea, Alicante, Spain 2014

The production of serotinous cones allows Pinus halepensis to dominate zones where fire is frequent.

Torres del Paine National Park, Patagonia, Chile 2019

Soil sampling campaign in the area affected by the fire in 2011. In the picture Jorge Mataix-Solera & Jorge Eduardo Jaña. Photo by Patricio Salinas (CONAF)

Gormaig Alcoy 2010

One year after fire. Area affected by fires 2 times in 15 years. High recurrence

Navalón Valencia 2008

Ash and sediments moved by runoff. Photo taken 6 months after fire

Torres del Paine National Park, Patagonia, Chile 2019

Soil sampling campaign in the area affected by the fire in 2011. In the picture Jorge Mataix-Solera. Photo by Jorge E. Jaña

Sierra de Mariola, Alicante, Spain

The role of mosses protecting the soil to avoid more erosion after fire and post-fire salvagge logging treatment (more info: García-Carmona et al., J. Environ Manag, 2020)

Sierra de Mariola, Alicante, Spain

Gully formed after a 50 mm rainfall in one afternoon, in a recently burned area and where the burned wood was extracted (salvagge logging treatment) (more info: García-Orenes et al., Sci Total Env, 2017).

In the picture, Jorge Moltó, Fuensanta García-Orenes, Vicky Arcenegui & Vicent Galbis

Sierra de Mariola, Alicante, Spain

The role of mosses protecting the soil to avoid more erosion after fire and post-fire salvagge logging treatment (more info: García-Carmona et al., J. Environ Manag, 2020)

Puig campana, Finestrat Alicante, Spain

Area affected by fire in 2008. Photo taken one year latter with high density of sprouting pines

Bocairent. Valencia, Spain 2010

One week after the fire. The bare soil is an immediate effect although temporal of high intensity fires leaving it very vulnerable to erosion processes

Photo used for an issue cover of the Spanish Journal of Soil Science (https://sjss.universia.net/issue/view/22)

Bocairent Valencia, Spain 2010

“Extra” weathering caused by fire. Rocks are altered by the heat both physical- and chemically

Pinoso, Alicante, Spain 2003

High intensity and severity fire. In the foreground of the picture there is not even burned vegetation structures and the color of the ash is very clear

Gorga, Alicante, Spain

Low intensity fire area. One month after fire starts to fall burned pine litter covering the soil creating a magnificent natural mulch

Surface of soil aggregates

The use of techniques such as XDR and SEM-EDX allow to detect the mineralogical changes that high severity fires can produce in the soil (more info: Jiménez-Pinilla et al., Catena 2016)

Galicia, Spain

Soil is a good isolator of heat transfer into the profile, in the first cms depth, sometimes can be observed how some parts are more affected than others by the changes in soil color, e.g.: white or grey colors indicate high degree of combustion, dark colors show remaining organic matter 

Sierra de Mariola, Alicante, Spain

The dissemination of what we know is as important as the research. Here there is a panel in a mountain with easy access to the people in an area affected by fires recurrently. Short key messages with illustrations

Teix, Torremanzanas, Alicante, Spain

Fire recurrence is a key factor. In the picture can be observed an area with less vegetation cover. This area was affected by 2 forest fires: one in 1987 and a second in 2005. The photography was taken in 2020.  A high fire recurrence can affect negatively to the ecosystem

Image from Mataix-Solera et al., Earth Science Reviews 2011

The upper few centimetres of surface soil can be affected by the combustion of the litter and soil organic matter, due to the heat released during fire. This, in turn, can affect aggregate stability. The images provide examples of soil affected by fire from different forested environments. A) Organic matter in the upper few centimetres has been quantitatively and qualitatively affected. The photo was taken seven months after a moderate intensity forest fire in Finestrat, Alicante, SE Spain (J. Mataix-Solera, 2009). B) Clay loam soil affected by the 2009 Black Saturday fires near Melbourne (Australia). The soil (grey) is overlain by a thick (5cm) ash layer. At the very top, organic matter has been oxidised as indicated by the pale brown colour. The charcoal above is likely to have been deposited subsequently from charred logs. C) Sandy soil in Sydney’s main water supply catchment, affected by the Christmas 2001 wildfires (Australia). The red colour suggests complete oxidation of organic matter and changes in mineralogy due to extreme heating under a burning log. D) Highly water repellent silty soil under a thick ash cover following a severe wildfire in conifer forest, Montana (USA). Arrows indicate water drops over water-repellent soil. Photos B, C and D courtesy of Stefan H. Doerr.

Graphical abstract from García-Orenes et al., Science of the Total Environment 2017

Effects of salvage logging on soil properties and vegetation recovery in a fire-affected Mediterranean forest: a two year monitoring research.

In the figures are represented the evolution of some soil properties during 2 years in control area (burned but without salvage logging), left image and  in salvage logging area (right image).

Montgó Natural Park, Javea, Alicante, Spain

Old terraces of stone walls built when agriculture was the main land use become visible after fire events in Mediterranean areas. Forests have invaded those areas where agriculture has been abandoned now for decades. Picture taken some months after a wildfire. Thanks to these terraces the soil is better preserved and erosion rates after a wildfire are lower than in slopes without them. More info about Management of fire-affected soils in the book chapter of Úbeda & Mataix-Solera, 2019 from the book: Fire Effects on Soil Properties Edited by: P. Pereira, J. Mataix-Solera, X. Úbeda, G. Rein, A. Cerdà. CSIRO Publishing (https://www.publish.csiro.au/book/7743)

Pego, Alicante, Spain

The beautiful Terra Rossa, skeletal but always protected from adversity by her “mother” rock. This area has been affected by forest fires in 2016 and 2022. Picture was recorded in September 2022, i¡one month after last fire.

Misti, Arequipa, Perú

Scrubland area affected by a recent forest fire in the Misti Volcano Mountain of Arequipa (Perú), 2022. In the picture can be observed the water repellency of the soil