 summed over different regions (growth, loop, shrinkage and fertility) in southern (Portugal) and central (France) *A. nodosum* and *F. serratus* populations.](pone.0000000.g000){#pone-0000000-g000}  ![Sensitivity of the population growth rate to changes in the survival transitions for each stage class in southern (Portugal) and central (France) *A. nodosum* and *F. serratus* populations.](pone.0000000.g000){#pone-0000000-g000}  Discussion {#s0} ==========  Th