Recent consequences of climate change have affected tree growth in distinct Nothofagus macrocarpa (DC.) FM Vaz & Rodr age classes in Central Chile

• Autores: Venegas González, Alejandro; Roig Junent, Fidel Alejandro; Peña Rojas, Karen; Hadad, Martín Ariel; Aguilera Betti, Isabella; Muñoz, Ariel A.
• Año de publicación: 2019
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: BASAL AREA INCREMENT; CLIMATE-GROWTH INTERACTIONS BY AGE CLASSES; DENDRO-ECOLOGY; HOTSPOT FOREST; MEDITERRANEAN FORESTS; MID-LATITUDE SOUTHERN HEMISPHERE; RISING ATMOSPHERIC CO2 CONCENTRATIONS; ROBLE DE SANTIAGO
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Forests play an important role in water and carbon cycles in semiarid regions such as the Mediterranean ecosystems. Previous research in the Chilean Mediterranean forests revealed a break point in 1980 in regional tree-ring chronologies linked to climate change. However, it is still unclear which populations and age classes are more affected by recent increases in drought conditions. In this study, we investigated the influence of recent variations in precipitation, temperature, and CO2 concentrations on tree growth of various populations and age classes of Nothofagus macrocarpa trees in Central Chile. We sampled 10 populations from five sites of N. macrocarpa through its whole geographic distribution in both Coastal and Andes ranges. We used standard dendrochronological methods to (i) group populations using principal component analysis, (ii) separate age classes (young, mature, and old trees), (iii) evaluate linear growth trends based on the basal area increment (BAI), and (iv) analyze the link between BAI and atmospheric changes using linear mixed-effects models. Results showed that young trees are more sensitive to climate variability. Regarding population grouping, we observed that all population clusters were sensitive to winter-spring precipitation, but only the Andes and Coastal populations were negatively correlated with temperature. The results of CO2 fertilization analyses were controversial and unclear. Since young trees from all population clusters reacted positively in the phase with an increase of atmospheric CO2 between 1980 and 2014, this behavior was not translated into growth for the last 15 years (2000-2014). However, it should be noted that the young trees of the highest elevation populations did not have a negative growth trend, so it seems that CO2 counteracted the negative effect of recent regional climate change (increase in temperature and precipitation decrease) in these population trees. Further studies are needed to assess the effects of climate variability over other ecological and physiological processes.
Fil: Venegas González, Alejandro. Universidad Mayor.; Chile
Fil: Roig Junent, Fidel Alejandro. 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
Fil: Peña Rojas, Karen. Universidad de Chile; 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: Aguilera Betti, Isabella. Pontificia Universidad Católica de Valparaíso; Chile. Universidad Austral de Chile; Chile
Fil: Muñoz, Ariel A.. Pontificia Universidad Católica de Valparaíso; Chile