Impact of solar activity on the growth of pine trees: case study

Abstract

In this work, we focus on the analysis of data for the ring width of two pine tree species: samples of six maritime pines (Pinus pinaster), grown in the north of Portugal, and one sample of Scots pine (Pinus sylvestris), grown in the south of Slovakia. A negative impact of solar activity (SA) was observed on the growth of these pine trees with particularly strong impact in the case of the maritime pines. The width of the annual rings was generally smaller in the years of maximum SA; furthermore, it was found that it is latewood width that is affected whereas earlywood width is not affected; as a corollary, the percentage of latewood also shows a significative negative correlation with SA.