Evaluación de la cobertura de vegetación ribereña leñosa presente en la llanura aluvial del río Biobío en el Gran Concepción en el periodo 2016-2023.
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Date
2024
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad de Concepción
Abstract
Históricamente los ecosistemas ribereños han sufrido perturbaciones a causa de la urbanización y la modificación del paisaje. Esto ha ocurrido especialmente en la Región del Biobío a través de la deforestación, sustitución y la habilitación de suelos. Actualmente se ha sumado la problemática de la megasequía que ha enfrentado Chile en las últimas décadas, que ha afectado directamente al río Biobío al ser de régimen pluvial, provocando una baja de caudal, aumento de la acumulación de sedimentos y, en consecuencia, aumento de vegetación. Los objetivos de este estudio buscaron evaluar la nueva vegetación ribereña leñosa del Río Biobío dentro del Gran Concepción. Se determinó su composición y estructura mediante 27 transectos en ambas riberas, como también se estimó el aumento de superficie de vegetación mediante los cambios de cobertura en el período 2016-2023 utilizando imágenes multiespectrales Sentinel-2 e Índices de Vegetación de Diferencia Normalizada interanual. Los resultados indican una estimación de 390,2 ha (60%) de aumento de vegetación ribereña en la zona de estudio entre los años 2016 y 2023. Se identificó un total de 15 especies, 11 introducidas, 2 nativas y 1 endémica. En términos de abundancia, destacan las especies introducidas, Alnus glutinosa con un 50% de los individuos muestreados, seguido por Salix babylonica con un 14,5% y Salix humboldtiana con un 6,8%.
Riparian ecosystems have unique characteristics as they are a transitional space, they are dynamic and provide different ecosystem services to society as well as refuge and connectivity for fauna. Historically, these ecosystems have been disturbed by urbanization and landscape modification. This has occurred especially in the Biobío Region through deforestation, substitution, and land development. Currently, the problem of the mega-drought that Chile has faced in recent decades has been added, which has directly affected the Biobío River as it has a pluvial regime, causing a decrease in flow, an increase in sediment accumulation and, consequently, an increase in vegetation. The objectives of this study were to evaluate the new woody riparian vegetation of the Biobío River within the Greater Concepción area. Its composition and structure were determined through 27 transects on both banks, as well as the increase in vegetation surface through cover changes in the period 2016-2023 using Sentinel-2 multispectral images and interannual Normalized Difference Vegetation Indices. The results indicate an estimate of 390,2 ha (60%) of increase in riparian vegetation in the study area between the years 2016 and 2023. A total of 15 species were identified, 11 introduced, 2 native and 1 endemic. In terms of abundance, the introduced species, Alnus glutinosa, stand out with 50% of the sampled individuals, followed by Salix babylonica with 14,5% and Salix humboldtiana with 6,8%
Riparian ecosystems have unique characteristics as they are a transitional space, they are dynamic and provide different ecosystem services to society as well as refuge and connectivity for fauna. Historically, these ecosystems have been disturbed by urbanization and landscape modification. This has occurred especially in the Biobío Region through deforestation, substitution, and land development. Currently, the problem of the mega-drought that Chile has faced in recent decades has been added, which has directly affected the Biobío River as it has a pluvial regime, causing a decrease in flow, an increase in sediment accumulation and, consequently, an increase in vegetation. The objectives of this study were to evaluate the new woody riparian vegetation of the Biobío River within the Greater Concepción area. Its composition and structure were determined through 27 transects on both banks, as well as the increase in vegetation surface through cover changes in the period 2016-2023 using Sentinel-2 multispectral images and interannual Normalized Difference Vegetation Indices. The results indicate an estimate of 390,2 ha (60%) of increase in riparian vegetation in the study area between the years 2016 and 2023. A total of 15 species were identified, 11 introduced, 2 native and 1 endemic. In terms of abundance, the introduced species, Alnus glutinosa, stand out with 50% of the sampled individuals, followed by Salix babylonica with 14,5% and Salix humboldtiana with 6,8%
Description
Tesis presentada para optar al título profesional de Ingeniero en Conservación de Recursos Naturales
Keywords
Llanuras aluviales, Plantas ribereñas, Conservación de la biodiversidad Chile Región del Bio-Bío