STRUCTURE AND DIVERSITY OF THE TREE COMUNITY OF A UPPER HIGHLANDS FOREST ON THE PLATEAU OF PO\uc7OS DE CALDAS, MG STATE

Foi realizado o levantamento da comunidade arb\uf3rea de uma floresta tropical superomontana, situada na Serra de S\ue3o Domingos, no planalto de Po\ue7os de Caldas, Minas Gerais, Brasil (altitude de 1.200 m a 1.575 m; 21\ub046'25\u201dS, 46'24\u201d10\u201dW), com o objetivo de avaliar as varia\ue7\uf5es estruturais e vari\ue1veis ambientais relacionadas. Foram analisados aspectos da estrutura fision\uf4mica (densidade, \ue1rea basal e distribui\ue7\ue3o de tamanho das \ue1rvores) e comunit\ue1ria (composi\ue7\ue3o, distribui\ue7\ue3o e diversidade de esp\ue9cies). Foram alocadas 22 parcelas de 5 x 100 m no fragmento para amostragem dos indiv\uedduos arb\uf3reos com di\ue2metro \ue0 altura do peito (DAP) 655 cm, e coleta de dados topogr\ue1ficos e amostras de solo superficial (0-20 cm) para an\ue1lises qu\uedmicas e texturais. Foram registradas 53 fam\uedlias bot\ue2nicas, 104 g\ueaneros, 178 esp\ue9cies e 1963 indiv\uedduos, assim como tr\ueas subgrupos de solos: Neossolos Lit\uf3licos, Cambissolos e Argissolos (distr\uf3ficos e eutr\uf3ficos), distribu\ueddos ao longo da varia\ue7\ue3o altitudinal do fragmento. Uma an\ue1lise de correspond\ueancia can\uf4nica revelou um gradiente de distribui\ue7\ue3o das esp\ue9cies arb\uf3reas principalmente correlacionada com as varia\ue7\uf5es altitudinais, o teor de Magn\ue9sio (Mg++) e satura\ue7\ue3o por alum\uednio (m).A survey of the tree community of a ombrophilous upper montane forest, situated in Po\ue7os de Caldas, Brazil (1200-1575 m of altitude; 21\ub046'25\u201dS, 46'24\u201d10\u201dW) was carried out in order to assess its environmental and structural variation. The physiognomic (density, basal area and distribution of size of the trees) and community structure (composition, distribution and diversity of species) were analyzed through 22 plots of 5 x 100 m, where the tree individuals with diameter at breast height 655 cm were sampled. The topographic variables were measured and the surface soil samples were collected to obtain their chemical and texture attributes. The survey resulted in 53 botanic families, 104 genera, 178 species and 1963 individuals, as well as four soil classes: distrofic and eutrofic Argisoil, Cambisoil and Litolic Neosoil, distributed sequentially from the hilltop to the base of the fragment. The canonic correspondence analyses showed a gradient of tree species distribution mainly correlated with variations of quotas, magnesium content (Mg++) and aluminum saturation (m)