Unconstrained ordination diagram of species and environmental variables projected showing results of the principal component analysis of relationships between the radial width index (RWI) of individual research plots, temperature (TemAnn – annual temperature, TemSea – seasonal temperature), precipitation (PrecAnn – annual precipitation, PreSea – seasonal precipitation), total solar irradiance (TSI), North Atlantic oscillation (NAO), NAOSea – seasonal NAO and sunspot number (SunNum).