SSS5.3Fire impacts on physical and chemical properties of ash, soils, and thermal analysis in soil science
|Convener: Paulo Pereira | Co-Conveners: Guillermo Rein , Claudio Zaccone , Anna Tsibart , Kajar Köster , César Plaza|
Thermal events can have important impacts over soil and its components as a transformation agent. In a minor scale, they can also be an innovative tool to analyze organic matter components and dynamics in highly complex matrices such as soil, sediment, composts, etc.
Fire is a global phenomenon with important implications for most Earth biomes. The evolution of many ecosystems cannot be understood without take into account the presence of fire. This makes fire a strong and important evolutionary force to Earth as we know it today. Fire can be considered as a soil formation factor and has short and long term implications. The impacts of fire on soil are interdependent; thus, it is important to understand its impacts on physics and chemistry of soils, but also how can they interact in a post-fire environment. Also ash is recognized to have a strong impact in soil after fire (e.g., soil cover, erosion, nutrients supply). It is well known that ash properties can have important implications on soil physical and chemical properties in the immediate period after the fire, where the soils are more vulnerable to erosion agents. Beside flaming fire, also smouldering has important impacts on soil physico-chemical properties and its impacts during and after the fire should be evaluated.
Although traditionally associated with material sciences, thermal analysis techniques have long been used in the study of soils, mainly in clay mineralogy. However, during the last decade, the exothermic reactions associated with the thermal oxidation of soil organic matter have received increasing attention. Thermal analysis and calorimetric techniques have been stated to potentially be able to characterize soil organic matter quality and the various mechanisms that act to stabilize it in the soil matrix. The demand for rapid and cost-effective methods to characterize complex environmental samples has increased the interest for these techniques.
The goal of the proposed session is double: i) understand the effects of fire on ash and soil physical-chemical properties of soils, either individually and in an integrated perspective; and ii) present the last theoretical, analytical and methodological advances in the application of thermal analysis and calorimetric techniques in biogeosiences, with special attention to their use in the characterization of the biogeochemical stability of soil organic matter in complex samples.