Recent multispecies tree-growth decline reveals a severe aridity change in Mediterranean Chile

• Autores: González Reyes, Álvaro; Christie, Duncan A.; Schneider Valenzuela, Isadora; Venegas González, Alejandro; Muñoz, Ariel; Hadad, Martín Ariel; Gipoulou Zuñiga, Tania; Tapia Marzan, Valeria; Gibson Carpintero, Stephanie; Santini Junior, Luiz; LeQuesne, Carlos; Villalba, Ricardo
• Año de publicación: 2024
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: TREE RING; MEDITERRANEAN; CHILE
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Soil moisture (SM) is a crucial factor in the water cycle, sustaining ecosystems and influencing local climate patterns by regulating the energy balance between the soil and atmosphere. Due to the absence of long-term, in-situ measurements of SM, studies utilizing satellite-based data and tree-ring analysis have become valuable in assessing variations of SM at regional and multi-century scales, as well as determining its effects on tree growth. This information is particularly pertinent in biodiversity hotspots made up of semi-arid ecosystems currently threatened by climate change. In the Mediterranean Chile region (MC; 30°-37°S), an ongoing megadrought in the MC since 2010 has resulted in a significant decline in the forest throughout the area. However, the impact of SM on tree growth at a multi-species and regional level remains unexplored. We analyzed a new network of 22 tree-ring width chronologies across the MC to evaluate the main spatiotemporal tree-growth patterns of nine woody species and their correlation with SM, using PCA. We also reconstructed the SM variations over the past four centuries and assessed its connection with large-scale climate forcings. Our results indicate that the primary growth patterns (PC1) explained 27% of the total variance and displayed a significant relationship with SM between 1982-2015 (r=0.91), accurately reflecting the current megadrought. The tree-ring SM reconstruction covers the period 1616-2018 and shows a strong decrease around the year 2007, revealing an unprecedented recent change in aridity with respect to the last four centuries. The intensity of the South Pacific Subtropical Anticyclone (SPA), which primarily owe their existence to the subsiding branch of the Hadley Cell, appears as the primary climatic mechanism correlated with the reconstruction and the present aridity conditions in MC. The current SM conditions align with anticipated aridity changes in MC, providing a bleak perspective of the future regional climate.
Fil: González Reyes, Álvaro. Universidad Austral de Chile; Chile
Fil: Christie, Duncan A.. Universidad Austral de Chile; Chile. Universidad de Magallanes; Chile
Fil: Schneider Valenzuela, Isadora. Pontificia Universidad Católica de Valparaíso; Chile
Fil: Venegas González, Alejandro. Universidad Bernardo O? Higgins;
Fil: Muñoz, Ariel. Pontificia Universidad Católica de Valparaíso; Chile
Fil: Hadad, Martín Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentina
Fil: Gipoulou Zuñiga, Tania. Universidad Austral de Chile; Chile
Fil: Tapia Marzan, Valeria. Pontificia Universidad Católica de Valparaíso; Chile
Fil: Gibson Carpintero, Stephanie. Universidad Bernardo O? Higgins;
Fil: Santini Junior, Luiz. Universidad Bernardo O? Higgins;
Fil: LeQuesne, Carlos. Universidad Austral de Chile; Chile
Fil: Villalba, Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina