Figure 1.

Mechanisms proposed by Price et al. (2014) for an increase of VLA with image magnification. A and B, The fractal coastline effect, by which VLA would increase systematically across all magnifications due to increasing line length at higher magnification, even in images of sufficient quality for all veins to be resolved (leaf of Plumeria alba from Price et al. [2014]), and the vein hierarchical effect, by which lower magnification images might include more 1° and 2° veins than higher magnification images, leading to lower VLA estimation. C to F, The lattice effect, by which zooming in within an image to areas of less than a single areole would lead to greater estimates of VLA because veins take up a disproportionate fraction of the image area relative to nonvein lamina; when a vein completely fills the image, the VLA equals the length of the image divided by the area of the image, which will tend to infinity as one zooms in on areas of ever smaller fractions of 1 mm (leaf of Machaerium acutifolium). Our analyses found that these mechanisms are not likely to influence typical VLA estimation or to account for the increase of VLA with magnification found by Price et al. (2014); the fractal coastline effect should not apply to the midline of veins used for VLA quantification, and typical images used for VLA estimation sample multiple areoles, typically avoiding 1° and 2° veins.