#Youngtree rarity %
youngtrees_youngtrees_rarity (Youngtree rarity %) float 100 0 100

#How much the rarity is reduced by fertility %
youngtrees_youngtrees_rarity_fertility (Youngtree rarity fertility reduction %) float 0.5 0 100

#Youngtree minimum fertility (-1 to +1)
youngtrees_youngtrees_fertility (Youngtree minimum fertility) float -0.3 -1 1