The sync.plot and sync.trend.plot have been modified to work with the new ggplot2 version 3.0.0. Minor issues from the previous DendroSync version 0.1.1 have been corrected in sync.trend.plot function.
Both plots, sync.plot and sync.trend.plot, have been also improved. Main improvements were related with legends and plot background colours. The plot theme has been changed to black and white. Now the plots have the same look as those in Alday et al. (2018) Dendrochronologia 47: 17-2.