7 research outputs found
FLORISTIC AND STRUCTURAL CHARACTERIZATION OF GALLERY FOREST FRAGMENTS OF UPPER ARAGUAIA RIVER BASIN
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
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
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)
Flora e estrutura do componente arb\uf3reo da floresta do Parque Ecol\uf3gico Quedas do Rio Bonito, Lavras, MG, e correla\ue7\uf5es entre a distribui\ue7\ue3o das esp\ue9cies e vari\ue1veis ambientais
Floristic composition and structure of an upper montane cloud forest in the Serra da Mantiqueira Mountain Range of Brazil
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