The qualitative behavior of <i>R</i>₀ as a function of the model parameters.

<p>The qualitative way by which <i>R</i>₀ depends on the values of the vector preference α, and the host transmission ratio, γ. Brown: <i>R</i>₀ is hump-shaped (diversity amplification), Green: <i>R</i>₀ is monotonic (dilution effect), Red: <i>R</i>₀ is constant (independent on species diversity). Note that <i>R</i>₀ is constant only at a single point where α = γ = 1, a case which is equivalent to a single host model. The red point is therefore disproportionally emphasized. It is apparent that diversity amplification is at least as common as the dilution effect in this parameter range. (i.e., 0.1≤γ≤4, 0.1≤ α ≤4).