Figure 5. Contrasting outcomes for equilibrium prevalence (A
and B) and host density (C and D) from hypothetical epidemiological
models that illustrate dynamics that rise when fitness traits (survival
and fecundity) and infectivity (transmission rate) vary with stressors,
as demonstrated by our meta-analysis results. A and C are simulation
outcomes of SI-Resource model. The half-saturation transmission constant
(ht) determines the transmission rate (β) response to
resource availability, where a greater value of ht makes
the β less sensible to resources, and vice versa. B and D are simulation
outcomes of SI-Environmental stress model. In the model, β could have
different sensitivities to environmental factors (βE),
ranging from positive to negative. For parameters used in each model
simulation, see Box 1 and 2, respectively.