Sun–earth relationship inferred by tree growth rings in conifers from Severiano De Almeida, Southern Brazil

This study of Sun–Earth relationships is based on tree growth rings analysis of araucarias (Araucaria angustifolia) collected at Severiano de Almeida (RS) Brazil. A chronology of 359 years was obtained, and the classical method of spectral analysis by iterative regression and wavelet method was applied to find periodicities and trends contained in the tree growth. The analysis of the dendrochronological series indicates representative periods of solar activity of 11 (Schwabe cycle), 22 (Hale cycle), and 80 (Gleissberg cycle) years. The result shows the possible influence of the solar activity on tree growth in the last 350 years. Periods of 2–7 years were also found and could represent a response of the trees to local climatic conditions. Good agreement between the time series of tree growth rings and the 11 year solar cycle was found during the maximum solar activity periods.

Research highlights
► Study of Sun–Earth relationships based on tree growth rings analysis of araucarias were performed by using an iterative regression spectral analysis and wavelets.
► The result shows the possible influence of the solar activity on tree growth in the last 350 years.
► Short periods observed in tree growth ring series are due to local environmental conditions of El-Niño and La-Niña events.