Alteración de la calidad del suelo por incendios forestales, en función del cambio climático en la provincia de Pichincha, Ecuador

Abstract

DOI: https://doi.org/10.46296/ig.v9i17.0322 Abstract Forest fires are one of the main factors altering Andean ecosystems, directly affecting the physical and chemical properties of the soil. This study aimed to evaluate the effect of fire severity on soil quality through the integrated analysis of satellite data and soil variables in an area affected by forest fires during the dry season (September–October 2024) in the province of Pichincha, Ecuador. Fire severity was determined using the Normalized Burn Rate (NBR) and its temporal variation (dNBR), employing pre- and post-fire satellite imagery from NASA, following the methodological guidelines proposed by the USGS and UN-SPIDER. Based on this classification, seven severity levels were established. Sixty-two soil samples were collected, according to the criteria established in Ministerial Agreement 097A. These samples were analyzed in the laboratory for a total of 21 analytical variables, prioritizing nine key variables: pH, electrical conductivity, organic matter, nitrogen, potassium, texture, calcium, sulfur, and phosphorus. The results show that high-severity fires generate a significant decrease in essential nutrients, alterations in soil texture, and changes in chemical equilibrium, while unburned soils and those affected by low-severity fires maintain more stable soil conditions. It is concluded that fire severity decisively controls the physicochemical dynamics of the soil, directly influencing its fertility, stability, and ecological recovery capacity. These results highlight the importance of incorporating fire severity as a fundamental criterion in management, restoration, and environmental planning strategies in scenarios of increased fires associated with climate change. Keywords: Soil, fire, climate change, drought.DOI: https://doi.org/10.46296/ig.v9i17.0322 Resumen Los incendios forestales constituyen uno de los principales factores de alteración de los ecosistemas andinos, afectando de manera directa las propiedades físicas y químicas del suelo. El presente estudio tuvo como objetivo evaluar el efecto de la severidad del incendio sobre la calidad del suelo mediante el análisis integrado de información satelital y variables edáficas en un área afectada por incendios forestales ocurridos durante la época de sequía (septiembre–octubre de 2024) en la provincia de Pichincha, Ecuador. La severidad del incendio se determinó a partir del Índice Normalizado de Área Quemada (NBR) y su variación temporal (dNBR), empleando imágenes satelitales pre y post-incendio de la NASA, siguiendo los lineamientos metodológicos propuestos por USGS y UN-SPIDER. Con base en esta clasificación, se establecieron siete niveles de severidad. Se recolectaron 62 muestras de suelo, conforme a los criterios establecidos en el Acuerdo Ministerial 097A, las cuales fueron analizadas en laboratorio para un total de 21 variables analíticas, priorizando nueve variables clave: pH, conductividad eléctrica, materia orgánica, nitrógeno, potasio, textura, calcio, azufre y fósforo. Los resultados evidencian que los incendios de alta severidad generan una disminución significativa de nutrientes esenciales, alteraciones en la textura del suelo y cambios en el equilibrio químico, mientras que los suelos sin quemar y aquellos afectados por incendios de baja severidad mantienen condiciones edáficas más estables. Se concluye que la severidad del fuego controla de manera determinante la dinámica físico-química del suelo, influyendo directamente en su fertilidad, estabilidad y capacidad de recuperación ecológica. Estos resultados resaltan la importancia de incorporar la severidad del incendio como criterio fundamental en estrategias de manejo, restauración y planificación ambiental en escenarios de incremento de incendios asociados al cambio climático. Palabras clave: Suelo, incendio, cambio climático, sequía. Abstract Forest fires are one of the main factors altering Andean ecosystems, directly affecting the physical and chemical properties of the soil. This study aimed to evaluate the effect of fire severity on soil quality through the integrated analysis of satellite data and soil variables in an area affected by forest fires during the dry season (September–October 2024) in the province of Pichincha, Ecuador. Fire severity was determined using the Normalized Burn Rate (NBR) and its temporal variation (dNBR), employing pre- and post-fire satellite imagery from NASA, following the methodological guidelines proposed by the USGS and UN-SPIDER. Based on this classification, seven severity levels were established. Sixty-two soil samples were collected, according to the criteria established in Ministerial Agreement 097A. These samples were analyzed in the laboratory for a total of 21 analytical variables, prioritizing nine key variables: pH, electrical conductivity, organic matter, nitrogen, potassium, texture, calcium, sulfur, and phosphorus. The results show that high-severity fires generate a significant decrease in essential nutrients, alterations in soil texture, and changes in chemical equilibrium, while unburned soils and those affected by low-severity fires maintain more stable soil conditions. It is concluded that fire severity decisively controls the physicochemical dynamics of the soil, directly influencing its fertility, stability, and ecological recovery capacity. These results highlight the importance of incorporating fire severity as a fundamental criterion in management, restoration, and environmental planning strategies in scenarios of increased fires associated with climate change. Keywords: Soil, fire, climate change, drought. Información del manuscrito:Fecha de recepción: 13 de octubre de 2025.Fecha de aceptación: 18 de diciembre de 2025.Fecha de publicación: 12 de enero de 2026