7 research outputs found

    FLORISTIC AND STRUCTURAL CHARACTERIZATION OF GALLERY FOREST FRAGMENTS OF UPPER ARAGUAIA RIVER BASIN

    Get PDF
    As florestas da bacia do alto Araguaia est\ue3o diariamente expostas a v\ue1rios agentes de degrada\ue7\ue3o devido \ue0 intensa pr\ue1tica de agricultura nessa regi\ue3o. Vinte e dois fragmentos (de 10 a 169 ha) foram inventariados pelo m\ue9todo de quadrantes centrados, com o objetivo de caracterizar a estrutura da vegeta\ue7\ue3o e criar um banco de dados de informa\ue7\uf5es voltado para programas de restaura\ue7\ue3o florestal na regi\ue3o. Foram amostradas 109 esp\ue9cies pertencentes a 78 g\ueaneros e 42 fam\uedlias. Dessas, 73,4% apresentaram padr\ue3o de dispers\ue3o zooc\uf3rica e 69,7% foram classificadas como de est\ue1dios iniciais de sucess\ue3o (53,2% secund\ue1rias iniciais e 16,5% pioneiras). O \uedndice de Shannon foi 3,86 nats.ind-1 e o de equabilidade de Pielou foi 0,82. As estimativas da densidade e \ue1rea basal, considerando todos os fragmentos, foram de 1.351 \ue1rvores.ha-1 e 19,28 m2.ha-1, respectivamente. As \ue1reas apresentaram uma menor riqueza (quando comparadas a matas de galerias mais conservadas), heterogeneidade nos \uedndices de diversidade e equabilidade, tamanho reduzido das \ue1rvores e consequente baixa \ue1rea basal, elevado n\ufamero de esp\ue9cies caracter\uedsticas de est\ue1dios intermedi\ue1rios de sucess\ue3o ecol\uf3gica e coloniza\ue7\ue3o de esp\ue9cies de cerrado e cerrad\ue3o em \ue1reas mais antropizadas, alterando a paisagem original. Tal situa\ue7\ue3o, somada \ue0 import\ue2ncia dessas \ue1reas para a conserva\ue7\ue3o da biodiversidade e de servi\ue7os ecol\uf3gicos (principalmente relativos \ue0 \ue1gua), exige a\ue7\uf5es de prote\ue7\ue3o e manejo conservacionista que aproveitem o grande potencial regenerativo da \ue1rea, dado pela exist\ueancia de um grande n\ufamero de esp\ue9cies secund\ue1rias iniciais e predom\uednio das esp\ue9cies zooc\uf3ricas.The forests of upper Araguaia river basin are daily exposed to degradation agents due to intense agriculture practices. Twenty two fragments (of 10 until 169 ha) were surveyed according to point-centered quarter method to characterize vegetation structure and to create a database to forest restoration. One hundred and nine (109) species, belonging to 78 genus and 42 families, were sampled where 73.4% revealed zoochorous dispersal pattern, and 69.7% were classified to initial sucessional category. Shannon index and Pielou equability index were 3.86 nats. ind-1 and 0.82, respectively. Density and total basal area estimated were 1,351 trees.ha-1 and 19.28 m2.ha-1. The areas showed lower richness, Shannon and Pielou heterogeneity indices, lower basal area, and high number of species of intermediate stage of ecological sucession and colonization of cerrado and cerrad\ue3o species in disturbed areas, altering the original landscape. Such situation, added to the importance of those areas for the biodiversity conservation and ecological services (mainly relative to the water), demands protection actions and management that use the great regenerative potential of the area, given by the existence of a great number of initial secondary species and the prevalence of zoochoric species

    ALLOMETRY AND ARCHITECTURE OF Copaifera langsdorffii (Desf.) Kuntze (FABACEAE) IN NEOTROPICAL PHYSIOGNOMIES IN SOUTHEASTERN BRAZIL

    Get PDF
    O objetivo deste trabalho foi analisar padr\uf5es alom\ue9tricos e fei\ue7\uf5es arquiteturais de Copaifera langsdorffii em diferentes fisionomias de uma regi\ue3o de tens\ue3o ecol\uf3gica. As fisionomias de floresta, corredor, cerrado e cerrado rupestre foram estudadas nos munic\uedpios de Lavras e Carrancas, sul de Minas Gerais, Brasil. Foram estudadas as rela\ue7\uf5es entre di\ue2metro do tronco, altura, \ue1rea da copa, grau de deflex\ue3o e deslocamento relativo da copa, sendo analisado o grau de semelhan\ue7a, entre as fisionomias, por meio de regress\uf5es e an\ue1lise covari\ue2ncia. Foi realizada uma an\ue1lise de componentes principais (PCA) com vari\ue1veis biom\ue9tricas coletadas e morfom\ue9tricas calculadas, para caracteriza\ue7\ue3o de grupos mais homog\ueaneos que evidenciem a plasticidade morfol\uf3gica da esp\ue9cie e suas diferentes estrat\ue9gias e investimento em recursos. Como resultado das an\ue1lises de regress\ue3o e covari\ue2ncia, encontraram-se padr\uf5es distintos, principalmente entre as fisionomias de floresta e cerrado, das fisionomias de cerrado rupestre e corredor. Um padr\ue3o de crescimento com maior investimento em altura na floresta, objetivando a garantia de espa\ue7o no dossel, e outro mais ligado ao crescimento horizontal da copa, nas fisionomias de cerrado rupestre e corredor. A PCA apresentou um gradiente de plasticidade morfol\uf3gica para a esp\ue9cie. A fisionomia de floresta apresentou maiores valores de altura total, largura de copa e di\ue2metro do tronco, e a fisionomia de cerrado rupestre mostrou valores mais elevados de grau de deflex\ue3o da copa (assimetria). O cerrado e o corredor formaram uma transi\ue7\ue3o entre floresta e cerrado rupestre, no gradiente de fei\ue7\uf5es morfol\uf3gicas da esp\ue9cie nas fisionomias.This study examined allometric patterns and architectural features of Copaifera langsdorffii , in different physiognomies in a region of ecological tension. The forest, corridor, \u2018cerrado\u2019, and rocky cerrado physiognomies were studied in the districts of Lavras and Carrancas, south of Minas Gerais state, Brazil. The relationships between stem diameter, height, crown area, degrees of deflection and relative displacement were analyzed, as well as the degree of similarity between the physiognomies by means of regressions and covariance analysis. The principal component analysis (PCA) was performed with the collected biometric and calculated morphometric variables to characterize the most homogeneous groups which show the morphological plasticity of the species and their different strategies and resources investment. As a result of the regression and covariance analysis, two distinct patterns were found mainly between forest and \u2018cerrado\u2019 physiognomies from rocky cerrado and corridor physiognomies. It was found a pattern of growth through higher investment in height in the forest, aiming to guarantee space in the canopy, and a more connected to the horizontal growth of the crown, in the rocky \u2018cerrado\u2019 and corridor. The PCA showed a gradient of morphological plasticity for the species. The forest physiognomy presented higher values of total height, crown width and stem diameter, while the rocky \u2018cerrado\u2019 physiognomy presented higher degrees of deflection of the crown (asymmetry). The \u2018cerrado\u2019 and the corridor formed a transition between forest and rocky \u2018cerrado\u2019 for the gradient of morphological features of the studied species in these physiognomies

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

    Get PDF
    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)

    Floristic composition and structure of an upper montane cloud forest in the Serra da Mantiqueira Mountain Range of Brazil

    No full text
    We analyzed the community structure of an upper montane cloud forest (elevation, 1900 m) in the Serra da Mantiqueira Mountain Range, in the state of Minas Gerais, Brazil. Our objective was to determine the comparative tree species richness and floristic diversity within this forest, which is at one of the higher elevations in the range, in relation to surrounding forests that are at lower elevations, adjusting for elevational gradients. Within 15 permanent plots (40 × 10 m each), we tagged all tree individuals with a diameter at breast height > 5 cm, registering their height and diameter. To compare the study area with neighboring cloud forests, we used the Sørensen similarity coefficient and phytosociological parameters. We sampled 1250 individuals distributed among 89 species, 55 genera, and 34 families. Canonical correspondence analysis revealed no gradients related to the vegetation or soil. We found that tree species richness and diversity were high in the study area. There was structural and floristic heterogeneity among the communities evaluated, underscoring the importance of conservation of these high-elevation ecosystems, which are so unique and irreplaceable
    corecore