Figure 2.
Theoretical framework on optimal allocation of leaf epidermal area for gas exchange. (a) Sign of the marginal ratio Λ Eqn 5, which represents the marginal change in g smax under a change in stomatal density (), relative to the corresponding marginal change in f gc (∂ f gc/ ∂ D s), as a function of the exponents S and P in the allometric relationships between D s and a gc Eqn 3, and between a gc and a max Eqn 4, respectively. In regions (I) and (III), an increase in D s leads to same‐signed changes of g smax and f gc (Λ > 0), whereas in region (II) an increase in g smax is tied to a decrease in f gc (Λ < 0). (b) Relationships between g smax and f gc depending on the scaling exponents S and P. The three lines correspond to the regions in (a). Arrows indicate the direction of change resulting from an increase in D s.