2.4.1. Canopy Architecture and Growth Parameters

Videos from the visible camera were processed automatically using a customized code written in Matlab^® R2020b to analyze frames following a computational process proposed by Fuentes et al. (2008) [22].

Canopy architecture parameters were obtained using the following algorithms considering the fractions of foliage projective cover (f_f), crown cover (f_c), and crown porosity (Φ), which were calculated using the following computational algorithms proposed by Fuentes et al. (2008) [22]:

where lg = large gap pixels, tg = total pixels in all gaps, and tp = total gap pixels.

LAI (adimensional) is calculated from Beer’s Law, defined as the total one-sided area of leaf tissue per unit 3 ground surface area [43]. Hence, the LAI values describe m² of leaf area per m² of soil.

where k = coefficient of light extinction (k = 0.5), which is applicable for tall trees [22], and the clumping index at the zenith, Ω(0), was calculated as follows:

The clumping index is a correction factor in obtaining effective LAI (LAIe), also adimensional, which is the product of:

Equation (5) describes the non-random distribution of canopy elements. If Ω(0) = 1 means that the canopy displays random dispersion, then for Ω(0)> or <1, the canopy is defined as clumped.