Relações espaciais e crescimento de canafístula (Peltophorum dubium (Spreng.) Taub.) e biomassa de Urochloa brizantha cv. BRS Piatã em Sistema Silvipastoril

Abstract

The choice of forest arrangements for association with pastures requires knowledge about the characteristics of the species used, in order to facilitate this association. The objective of this study was to evaluate the spatial and temporal variation of some attributes of tree growth at different ages and densities, and assess the influence of the density of canafístula trees on microclimate, yield and quality of herbage Piatã. Was carried out in December 2009 a Nelder wheel with 24 spokes and 22 rings where the tree component was the canafístula (Peltophorum dubium (Spreng.) Taub.). It was evaluated 432 trees to verify the spatial dependence of the data and 10 densities of trees to the responses of dendrometric attributes, microclimate, production and nutritive value. The analyses were based on descriptive statistics and spatial dependence of the height of the trees (ALT), stem diameter (D1,3), crown diameter (Dc) and cylindrical volume (VC) at 13 25 and 37 months of age. Regression analyzes were developed and when required, the response surface for the same attributes beyond the microclimatic variables, dry matter production and nutritional value of the grass Piatã the initial stage of growth and intercropping with grass Piata the dendrometric variables canafístula present with small catchment area, however with high spatial dependence. The height growth of trees canafístula was directly related to population density, while for the bole and crown diameter and canopy area and cylindrical volume, this ratio was inversely proportional. Considering the relations between the variables dendrometric the canafístula shown to be a species adapted to population changes. Highest population densities canafístula provided favorable to the growth of grass Piata microclimate. The production of dry matter in general, was not compromised by increased tree density in 13 any of the two periods, water and dried. The nutritional value of grass Piata was positively influenced by higher tree density, with higher values in the dry season.