Fire in the Semiarid Pampa: untangling the impacts of fire on soil properties affecting wind erosion and dust emissions under different land uses

• Applicants: Dr. Roger Funk; Dr. Miriam Britt Marzen
• Subject Area: Soil Sciences
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 544089070

The semiarid Argentinean Pampa comprises a range of vegetation types on humusrich soils of aeolian origin and is periodically subject to naturally occurring wildfire. The transition zone between rainfed agriculture and more arid Pampa which is often used as pasture, exhibits local heterogeneities of soil characteristics. While the Loess soils with a high fine sand content are considered stable if protected by the dense natural grassland vegetation and physical and biological crusts, an increasing land use pressure including agriculture and grazing have been leading to a degradation of large areas of the vegetation cover. The combined effects of land use pressure, climate-change driven increased precipitation variability and more frequent fires are likely to increases the general susceptibility of the entire ecosystem but have not been comprehensively assessed yet. As one key factor we investigate the impact of fire on the erodibility of soil by wind including the emission of dust and fine dust on a local to regional scale. We focus different soil surfaces with the vegetation types grassland, shrubland and light forest featuring respective key parameters related to percentage surface cover, crust, roughness and substrate. Additionally, we expect to highlight variabilities concerning the spatio-temporal extent and temperature exhibited to soil and surface and their impact on wind erosion and dust emissions. Based on on-site measurements on pre- and post-fire soils including dust sampling, soil sampling and the experimental device wind tunnel, we derive urgently needed data on the interplay of soil, surface parameters and fire. The observed data are quantitatively and qualitatively analysed to derive information about on-site redistribution of mineral and organic substances. To approach upscaling of local data on a regional scale, GIS-applications and an adapted modelling are applied. The goal of the project is the deepening of process understanding of the intensively anthropogenic influenced landscape-soil-fire nexus in the Pampa environment including the quantification of moved sediment and target nutrients.

• DFG Programme: Research Grants
• International Connection: Argentina
• Partner Organisation: Consejo Nacional de Investigaciones Científicas y Técnicas
• Cooperation Partners: Dr. Fernando Avecilla; Dr.-Ing. Juan Esteban Panebianco