Laboratory of Conservation and Dynamics of Volcanic Soils

The number of forest fires and burned areas in the central-southern region of Chile has surpassed the historical figure of 50,000 hectares per year, causing dramatic consequences for ecosystems and the forestry sector. This area is exceptionally susceptible to progressive soil degradation and nutrient loss, which hampers vegetation recovery and reduces the productivity of forest plantations and ecosystem services (such as carbon sequestration). The objective of this study is to investigate the impacts of forest fires on the soil functionality of native forests (Nothofagus spp.) and exotic forest plantations (Pinus radiata De Don), focusing on nutrient losses, soil erosion, the water cycle, and biological alteration, among other properties. By employing a wide range of innovative experimental methods, simulation modeling, and spatial-temporal scaling processes, we will examine how extreme forest fires alter the ecosystem and consequently vegetation regeneration in the Mediterranean bioclimatic zone of Chile between latitudes 36ºS and 37ºS. The study will be conducted on eroded Alfisols in the Coastal Range and volcanic Andisols in the foothills of the Andes. The methodology will be based on a novel approach of expansion (spatial and temporal) that combines pairs of Experimental Core Sites – locations for detailed mechanistic investigations – Long-Term Monitoring Basins, and Fire Chronosequence Study Sites with different fire ages. All areas include both forest plantations and native vegetation. In the Core Sites, small-scale artificial fires will be used to assess the direct effects of fire on soil, biology, nitrogen and phosphorus availability, and soil hydraulic properties. We will employ innovative multi-labeling of vegetation (15N, 13C, Cs, Rb, Sr) to determine element flows post-fire across different biogeochemical compartments. Additionally, potential monitoring locations in basins with ongoing long-term hydrological measurements will be identified (e.g., water discharge and sediment loads). In the selected basins, nutrient and hydrological flows will be quantified after a recent forest fire (<1 year). Fire chronosequence study sites will evaluate critical changes in soil characteristics during natural vegetation regeneration and plantation growth after forest fires (between 1 and 20 years). The processes measured at the Core Sites and temporal changes in the chronosequences will parameterize models, the outcomes of which will be applied to each Monitoring Catchment Site. The effects of forest fires on soil degradation will be integrated into the 3PG Forest Growth mechanistic model and the SWAT (Soil and Water Assessment Tool) model to estimate the impact of forest fires on soil fertility, hydrology, nutrients, and erosion losses. Based on fire chronosequences and in close collaboration with major Chilean private forest companies, recommendations will be suggested to restore the water and nutrient balance of the ecosystem following forest fires, contributing to defining strategies for water conservation and implementing appropriate soil recovery and erosion control techniques. The FiRING project will establish a process-based understanding of the effects of forest fires on forest soil degradation, providing technical recommendations that could be incorporated into management practices for soil health recovery and functionality of burned forest ecosystems. The FiRING project will strengthen and expand international and national collaboration networks, establish a strong link between basic and applied science with connections to local government agencies and private forest companies, and benefit local communities and society. The dissemination of expected results will extend to the academic sphere through traditional channels, and to professional and educational levels through video capsules and outreach brochures for children, as well as conferences for forestry professionals (e.g., park rangers, industry representatives, managers, and technical personnel from private companies)