Fig. 2
From: Limited impacts of climatic conditions on commercial oil palm yields in Malaysian plantations
Variation in oil palm yield among study plantations, with plantations ranked by median annual yield. a Boxplots of annual yield for each full year of harvest in each oil palm field, by plantation. Dashed grey line represents potential annual yield for many coastal areas in Malaysia (36 t/ha), after Hoffmann et al. (2014). Boxplot centre lines show the median, lower and upper hinges show the first and third quartiles respectively, whiskers extend to the maximum and minimum values within 1.5 × inter-quartile range, and outliers are plotted individually. b Monthly oil palm yield in each plantation, including regular seasonal fluctuations. Solid and dashed black lines show predicted monthly yield values from the final GAMM of raw yield and climatic variables (mean and 95% confidence intervals). The predictions incorporate both cyclic cubic regression splines of seasonality fitted across months per plantation, and random intercepts fitted for each plantation, with all other numeric predictors held at the median value, and were back-transformed from a square-root transformation for plotting. Grey violin plots show distribution of actual monthly yield data for each month in each plantation