Modelagem do crescimento para plantios de eucalipto no norte de Minas Gerais, Brasil

Abstract

Commercial plantations of Eucalyptus has increased in Brazil, mainly in the state of Minas Gerais. The assessment of the effects of soil and climatic variables on the growth of trees becomes important tool to optimize management activities. In this perspective, this study aims to adjust and parameterize the 3-PG model for the North of Minas Gerais, using data from permanent plots of forest inventory, climate data from weather stations and data from remote sensing. This study was conducted in Eucalyptus of commercial plantations in the city of Bocaiuva (Minas Gerais). To parameterize the constant parameters of the relationship between DAP and height (H) relationship of power between DAP and height (NHB), constant relationship between volume and DAP (aV) and relationship of power between volume and DAP (NVB) were used in 2031 comments. The PG-3 model was run with parameters suggested in literature for the region and then executed with changes in the parameters mentioned above. To evaluate the effect of climate variability on planting were assessed estimates of 3-PG model fed with climatological normal and monthly averages and then analyzed the effects of environmental modulators fans and fDPV on the growth of planting. The database of climatological normals were obtained from INMET and global solar radiation was obtained from the GL 1.2 model for South America. The database with monthly average was acquired by INMET, and the precipitation was obtained from tropical TRMM satellite and solar radiation was estimated by the model proposed by FAO 56. Subsequently, we evaluated the efficiency of the 3-PG model in estimating the growth and production of settlement regarding estimates of empirical models, considering the FR parameter (Fertility Rating) as a site quality indicator. Through significant improvement was observed statistical analysis of procedural modeling with the modification of the suggested parameters, indicating that the values of this parameter can be used for other municipalities that region. Statistical analyzes showed that there was a reduction of variation of the data through the standard error of estimate (Syx%) and model efficiency (EF) greater than 0.80 for DBH, height and volume, indicating significant improvement in the model estimates . Comparing the estimates of dendrometric variables with climatological normal and monthly averages, it is observed, the graphics, the estimates were similar, with the monthly averages showed higher estimates. Statistical analysis demonstrated that the monthly averages were closer to those observed data, Syx 28% and EF 0.82 to volume while normal climatic Syx% showed almost 60% and EF 0.22. fAS modulator showed greater restriction on the development of trees, especially in the months of July, August and September. The procedural modeling showed average yield estimates in respect of empirical modeling, and the site estimated by 3-PG showed values close to the average estimated by site traditional model. The FR parameter on soil fertility, showed good relationship with the classification of production sites, and further studies to improve the accuracy in the classification of sites indexes. The 3-PG model can make accurate estimates of dendrometric variables, showing an important tool for evaluating areas with fitness for forest production, considering the effect of environmental and climate variables in the growth of trees. The procedural modeling can be used together with empirical tools to assess the growth and production of forest plantations on different management activities and in the future producing areas.