Fig. 5: Precipitation during the olive phenological stages.
From: Olive production in the 21st century will be threatened by water stress and declining solar activity
a Link between olive tree influx and March-November precipitation (expressed in mm) during the last 8000 years. The long-term trend is shown as a linear regression and a polynomial model (order 4). Boxplots show the evolution of olive tree influx every 10 mm. b The long-term periodicity of precipitation compared with the periodic olive signal. The periods of low/high pollen production are highlighted by different colours.
