Abstract
Fire induced soil water repellency (WR) is controlled by many different factors (temperature reached, amount and type of fuel, etc.). Soil properties may determine the occurrence and intensity of this property in burned soils. The objectives of this paper are to make advances in the study of soil properties as key factors controlling the behaviour of fire-induced WR, and to study the impact of pre-fire SOM content and SOM quality in fire-induced soil WR. In this research, experimental laboratory burnings were carried out using soil samples from different sites with different lithologies, soil types and plant species. Soil samples taken from the same site differ only in quantity and quality of soil organic matter, as they were collected from under different plant species. All soil samples were heated in a muffle furnace at 200, 250, 300 and 350 ºC without the addition of any fuel load. WR was measured using the water drop penetration time test (WDPT). The results showed significant differences between soil types and plant species, indicating that small differences in soil properties may act as key factors controlling the development and persistence of WR reached, with burned soil samples ranging from wettable to extremely water repellent. The main soil property controlling the response was texture, specifically sand content. The quality of organic matter was also observed to have an effect, since soil samples from the same site with similar organic matter contents, but taken from beneath different plant species, showed different WR values after burning.
Highlights
Water repellency (WR) is a property of soils that can occur under natural conditions (MataixSolera et al 2007; Lozano et al 2013; Jordán et al 2013) but it is one that is usually induced or enhanced as a result of forest fires in Mediterranean environments (Mataix-Solera and Doerr 2004; Arcenegui et al 2008; Zavala et al 2009a)
Mataix-Solera et al (2008) confirmed under laboratory burning conditions that terra rossa soils showed very low susceptibility to develop water repellency (WR) by burning. They concluded that this process is controlled by different soil properties, such as organic matter and clay content and, even more importantly, clay mineralogy, as it was found that kaolinite content was the key factor controlling the occurrence of fire-induced WR in terra rossa soils
Soil acidity is higher in soil samples from “Los Alcornocales” Natural Park, especially in the sandy loamy/loamy sandy samples (HF1, HF2 and HF3), with a pH between 6.2 and 6.8, compared with samples from Alicante (HF6 to HF12), where the mean annual rainfall is substantially lower (Table 1), and the pH ranges from 7.8 to 8.2 (Table 3)
Summary
Water repellency (WR) is a property of soils that can occur under natural conditions (MataixSolera et al 2007; Lozano et al 2013; Jordán et al 2013) but it is one that is usually induced or enhanced as a result of forest fires in Mediterranean environments (Mataix-Solera and Doerr 2004; Arcenegui et al 2008; Zavala et al 2009a). Mataix-Solera et al (2008) confirmed under laboratory burning conditions that terra rossa soils showed very low susceptibility to develop WR by burning. They concluded that this process is controlled by different soil properties, such as organic matter and clay content and, even more importantly, clay mineralogy, as it was found that kaolinite content was the key factor controlling the occurrence of fire-induced WR in terra rossa soils. Recent studies in areas affected by wildfires in Spain and Israel have confirmed this behaviour (Mataix-Solera et al 2013)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
