Fig. 4: Olive pollen production in relation to 10Be and September–November insolation.
From: Olive production in the 21st century will be threatened by water stress and declining solar activity
a Violin boxplot showing the distribution and probability density of each time series (pollen production influx and cosmogenic radionuclide 10Be). The periods of low/high pollen production are highlighted by different colours. Increases and decreases are expressed as percentages on the graph. b September–November insolation dataset (expressed in Wm−2), compared with the olive tree signal shown with a 200-year moving average and a sinusoidal regression.
