Plot the richness values for the landscape created by the user
Details
This auxiliary function plots the plant richness values of the
landscape when the landscape is configured (see Compute Initial Richness
button in the app), and also the final richness (after the Dispersers and
Simulation modules were chosen by the user in the app). In both cases
plot_richness plots the plant richness for each pixel within each of the
landscape categories.
Author
Antonio J Pérez-Luque (ajpelu@gmail.com)