Modelagem biométrica e ecofisiológica em plantios de Pinus taeda no Brasil e nos Estados Unidos

Abstract

The reliable estimation of forest productivity, including the effect of edaphoclimatic and physiological factors, in addition to stand variables, has been recognized as a crucial tool for forest management planning. Throughout the thesis, three articles were developed to assist in the management of Pinus taeda in Brazil and the United States. The first article was a literary and systematic review of the approach to competition in statistical (Growth and Yield Models – G&YM) and process-based models (PBM) of growth and production in plantations of Pinus and Eucalyptus. In the second one, we sought to understand the difference in the growth of Pinus taeda plantations in half rotation-aged between Brazil and United State through the variables absorption (APAR) and light use efficiency (LUE), using the MAESTRA model. The third article presented an alternative for modeling APAR and LUE as a function of P. taeda stand variables. The review showed that competition in most articles is treated indirectly using basal area, number of trees, density and competition for light. The number of articles with the genus Pinus was very small, and the application of PBM was not observed, that is, there is a gap for more studies with this genus to be carried out in Brazil, especially with this modality of model. The results of the second article showed that the light use efficiency of P. taeda genotypes is similar in Brazil and the United States, where trees with greater growth space have greater leaf area, greater light absorption and wood biomass. Clonal genotypes are more efficient in the use of light in closed spacing than open-pollinated varieties in Brazil. Thus, LUE explains growth variations between genotypes and spacings, while APAR was better at differentiating WNPP (Wood Net Primary Production) rates between sites. Finally, in the third article, the APAR model included in the monomolecular model the variables basal area (G) and quadratic mean diameter (dg). In the LUE model, the variables number of trees per hectare (N/ha), dominant height (HD) and the PV50 uniformity index were selected. Scenarios were simulated and occurred that show the increase of APAR with the increase of G and G. LUE increases with HD and N/ha and decreases with PV50. The methodological approach presented is the first to include forest inventory variables in parameters that are used in production ecology and process-based models. The general results showed that APAR better explains the difference in P. taeda growth between Brazil and the United States and the approach of including stand variables in parameters used in production ecology and process-based models, showing potential for use in future and improvement, this being a pioneering methodology of integration between G&YM and PMB.