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How Rock Fragments and Moisture Affect Soil Temperatures during Fire
Author(s) -
Stoof Cathelijne R.,
De Kort Annemieke,
Bishop Thomas F.A.,
Moore Demie,
Wesseling Jan G.,
Ritsema Coen J.
Publication year - 2011
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2010.0322
Subject(s) - water content , environmental science , rock fragment , moisture , soil science , geology , geotechnical engineering , materials science , composite material , paleontology , quartz
Soil heating during forest fires can considerably impact the soil system, with effects ranging from seed and microbe mortality to nutrient losses and structural degradation. Because soil heating is related to soil moisture and composition, the impact of fire may also depend on the presence of rock fragments in and on the soil. In laboratory burning experiments, the effect of rock fragments on soil heating was evaluated using factorial combinations of soil moisture, rock fragment cover, and rock fragment content. Soil moisture significantly reduced maximum temperatures as well as the depth and duration of sustained temperatures (duration of heating) above 60 and 175°C. Effects decreased with depth. A rock fragment cover similarly protected the soil from high maximum temperatures, especially in dry soil. While it decreased the depth of lethal heating from 3 to 2 cm, it increased the duration of heating at the soil surface. Incorporated rock fragments had no significant effect on maximum temperature or the depth of lethal heating, and effects on heating duration were limited to dry or bare soil. The data suggest that by changing the degree of soil heating, rock fragments may reduce the risk of fire‐induced biological, chemical, and physical degradation but increase the biological impact of fire at the soil surface. These findings have implications for controlled fire decision making in rocky areas where soil heating is desired or should be avoided.