Índice de área foliar en sistemas silvopastoriles en Eucalyptus grandis y dunni

This study evaluated the vertical distribution of leaf area index (LAI) and light transmittance in a silvopastoral system with Eucalyptus grandis and Eucalyptus dunnii, comparing single-row and triple-row planting arrangements. Ten representative trees were selected, and each crown was subdivided into four strata. In each stratum, light transmittance was measured using a ceptometer, and LAI was estimated with the LAI-2200 canopy analyzer. A destructive determination of leaf area was later performed through digital leaf scanning to compare with the indirect measurements. E. grandis exhibited a mean height of 4.7 m, a diameter at breast height (DBH) of 4.6 cm, and a live crown height of 4.4 m, exceeding E. dunnii by 1 m, 0.66 cm, and 0.7 m, respectively. Light transmittance followed a negative exponential function and was influenced by both species and planting arrangement. LAI values were low in the single-row arrangement (0.3–0.4) and substantially higher in the triple-row arrangement (1.2–2.1). The indirect method (LAI-2200) consistently underestimated LAI compared with the destructive WinDIAS measurements. In the single-row arrangement, species differed markedly in transmittance: in the H0–H1 stratum, E. grandis showed 57% lower transmittance than E. dunnii, while differences in the H1–H2, H2–H3, and H3–Crown strata were 22%, 50%, and 11% respectively, always with lower values for E. grandis. In contrast, in the central row of the triple-row arrangement, the pattern reversed, and E. grandis exhibited 58% higher transmittance than E. dunnii in the H0–H1 stratum. The combined characterization of light transmittance and LAI provides relevant information for the design and management of silvopastoral systems with Eucalyptus spp., offering tools to optimize resource use and improve system viability by understanding how these variables influence both tree growth and understory forage production.