Is it real or apparent increased aggregate stability sometimes found in burned soils?

Autor: V. Arcenegui, J. Mataix-Solera, A. Morugan-Coronado, A. Pérez Bejarano, P. Jiménez-Pinilla, E. Lozano, J. Mataix-Beneyto, A. Jordán, L.M. Zavala, F. García-Orenes
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Zdroj: Flamma, Vol 4, Iss 2, Pp 101-104 (2013)
Popis: The increase in soil aggregate stability observed in many cases after burning is discussed in this paper. Soil samples under pine forest from two Mediterranean areas were collected for this experiment: acid soils from El Algibe Range (Los Alcornocales Natural Park, Cádiz, Southern Spain) and calcareous soils of Sierra de la Grana (Alicante, Eastern Spain). In each case, soil aggregates (2 to 0.25 mm) were selected and exposed to temperatures of 200, 250, 300, 500 and 700 oC during a 20-minutes period. In both cases weight loss after volatilization of substances and a significant destruction of aggregates with increasing temperature were observed. For acid soils, where organic matter is the main cementing agent, destruction of aggregates with temperature was more intense. Water repellency induced by combustion increased between 200 and 250 oC, also the remaining aggregates remaining increased within the initial size fraction after heating, increasing its stability. For temperatures above 300 oC, water repellency disappeared, although an increase in aggregate stability was observed, possibly due to changes in the mineral soil fraction. Therefore, it is concluded that burning may destroy part of the aggregates by combustion of organic matter, so selecting stable aggregates. Water repellency and transformations of soil minerals contribute to increased stability in selected aggregates.
Databáze: OpenAIRE
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