Interação genótipo e espaçamento na forma do fuste e eficiência no uso da luz em plantios de Eucalyptus sob um gradiente climático no Brasil

Abstract

The development of forest modeling is a useful tool for understanding the factors that influence the growth, taper, and productive efficiency of trees and thus provides a basis for more assertive decision-making by forest managers. This thesis was structured under two research approaches, and three scientific articles were developed. In article 1, we performed a systematic and bibliometric review of the evolution of the process-based model's MAESTRO, MAESTRA, and MAESPA and its applicability in forestry research over 32 years. This type of model is free code and can represent the tree individually, calculating the interception of solar radiation across the canopy. The focus of research that's on the rise is on Eucalyptus, and the USA is the country that leads the research using this model. In article 2, the database was composed of information from two Eucalyptus genotypes of the plastic-type planted on four sites with distinct soil and climate characteristics and subjected to different gradients of planting spacing on two dates. The application of the MAESTRA model with emphasis on understanding the light use efficiency (LUE) for the biomass production of the stem of eucalyptus trees and this is the first work with MAESTRA simulation in spacing and location gradient experiments developed until now for Eucalyptus. We observed that the behavior of genetic materials evaluated compared with the photosynthetically active radiation absorbed by trees (APAR) and LUE varied as a function of the site, date of analysis, and spacing. In paper 3, we used data from 17 experimental sites and 18 Eucalyptus genotypes distributed between these sites. A generalized and calibrated tapering model was developed. The variables age and soil water deficit, interactively with the variable z (hi/ht) were included in the exponent of the model and the algebraic constraint method was used to constrain the function to pass through the diameter located at 6 m tree height. The overall results of the chapters were important to compose information about studies of light use efficiency about to with concerning biomass and stem tapering for Eucalyptus trees with different edaphoclimatic information and different ages.