Crossing a critical threshold: Accelerated and widespread land use changes drive recent carbon and nitrogen dynamics in Vichuquen Lake (35 degrees S) in central Chile

Fuentealba, Magdalena; Latorre, Claudio; Frugone-Alvarez, Matias; Sarricolea, Pablo; Godoy-Aguirre, Carolina; Armesto, Juan; Villacis, Leonardo A.; Carrevedo, M. Laura; Meseguer-Ruiz, Oliver; Valero-Garces, Blas

Abstract

Global afforestation/deforestation processes (e.g., Amazon deforestation and Europe afforestation) create new anthropogenic controls on carbon cycling and nutrient supply that have not been fully assessed. Here, we use a watershed-lake dynamics approach to investigate how human-induced land cover changes have altered nutrient transference during the last 700 years in a mediterranean coastal area (Vichuquen Lake). We compare our multiproxy reconstruction with historical documentation and use satellite images to reconstruct land use/cover changes for the last 45 years. Historical landscape changes, including those during the indigenous settlements, Spanish conquest, and the Chilean Republic up to mid-20th century did not significantly alter sediment and nutrient fluxes to the lake. In contrast, the largest changes in the lake-watershed system occurred in the mid-20th century and particularly after the 1980s-90s and were characterized by a large increase in total nitrogen and organic carbon fluxes as well as negative shifts in sediment delta N-15 and delta C-13 values. This shift was coeval with the largest land cover transformation in the Vichuquen watershed, as native forests nearly disappeared while anthropogenic tree plantations expanded up to 60% of the surface area. (C) 2021 Elsevier B.V. All rights reserved.

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Título según WOS: Crossing a critical threshold: Accelerated and widespread land use changes drive recent carbon and nitrogen dynamics in Vichuquén Lake (35°S) in central Chile
Título de la Revista: SCIENCE OF THE TOTAL ENVIRONMENT
Volumen: 791
Editorial: Elsevier
Fecha de publicación: 2021
DOI:

10.1016/j.scitotenv.2021.148209

Notas: ISI