Variações estruturais do lenho de espécies de cerrado do estado de São Paulo
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Data
2007-02-02
Autores
Oliveira, Julia Sonsin [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Informações sobre características anatômicas do xilema secundário de espécies de cerrado são escassas, porém de grande importância, uma vez que o cerrado é influenciado por fatores ambientais diversos e as espécies que aí se encontram apresentam características morfológicas externas e internas peculiares. Estes estudos permitem compreender a influência dos fatores ambientais nas características estruturais do lenho. O presente trabalho tem por objetivo verificar os padrões e as variações estruturais do lenho, bem como determinar possíveis características de valor taxonômico e ecológico de 48 espécies arbustivas e arbóreas, incluídas em 27 famílias, ocorrentes em área de cerrado localizada no município de Pratânia, região centro-oeste do estado de São Paulo, Brasil (23º 02’ 55,5” S e 48º 31’ 26,1” W). Foram amostrados três espécimes para cada espécie e de cada espécime foi coletado o ramo mais desenvolvido da copa. Destes ramos foram retirados discos que tiveram sua porção basal polida para as análises macroscópicas qualitativas e para as análises microscópicas quali e quantitativas das características anatômicas do lenho. Verificou-se, destas análises, a presença de células perfuradas de raio (CPR) em sete espécies e, desta forma, decidiu-se por coletar também as raízes destas espécies para averiguar a presença das CPR no lenho destas. As raízes foram coletadas a uma profundidade de aproximadamente 30 cm. Nas amostras das raízes foram realizadas análises qualitativas e quantitativas das CPR. No lenho dos ramos caulinares das espécies foram caracterizados os marcadores de crescimento, bem como foi descrita a estrutura das camadas de crescimento. Os seguintes padrões foram observados: camadas de crescimento bem definidas (61% das espécies), mal definidas (33%), e ausentes (6%); porosidade difusa (94%), anel semi-poroso...
Information about the secondary xylem anatomy of cerrado species are scarce, but of great importance, since cerrado is influenced by the environmental factors its species show peculiars external and internal morphologic characteristics. These studies allow a better comprehension of the environmental factors influence on the structural characteristics of the wood. These studies aims to verify patterns and the structural variations of the secondary xylem, and also to determine the characteristics of ecological and taxonomic value of 48 shrubby and arboreal species, from 27 families of the Pratânia’s cerrado region, located in the west central part of the state of São Paulo, Brazil (23º 02’ 55, 5” S e 48º 31’ 26,1” W). In these studies we obtained three specimens from each species. From each specimen we collected the most developed branches of the treetops. From the collected branches, samples were taken and its basal portion polished for the qualitative macroscopic analysis and also for the qualitative and quantitative microscopic analysis of the secondary xylem characteristics. From these analyses, we verified the presence of perforated ray cells (PRC) in seven species and also we decided to collect roots to verify the presence of PRC’s in the secondary xylem of these species. The roots were collected to a depth of 30 cm, and on the samples qualitative and quantitative analyses were performed on the PRC. On the secondary xylem of branches we characterized the growth ring markers and described the structure of the growth layer. The following patterns were observed: growth rings well defined (61%), poorly defined (33%), absent (6%); diffuse-porous (94%) and semi-ring-porous (6%); without vessel arrangement (84%), in radial pattern (10%) and in tangential bands (6%); solitary and multiple vessels (94%) and exclusively solitary (6%); simple perforation plate (90%) ...(Complete abstract click electronic access below)
Information about the secondary xylem anatomy of cerrado species are scarce, but of great importance, since cerrado is influenced by the environmental factors its species show peculiars external and internal morphologic characteristics. These studies allow a better comprehension of the environmental factors influence on the structural characteristics of the wood. These studies aims to verify patterns and the structural variations of the secondary xylem, and also to determine the characteristics of ecological and taxonomic value of 48 shrubby and arboreal species, from 27 families of the Pratânia’s cerrado region, located in the west central part of the state of São Paulo, Brazil (23º 02’ 55, 5” S e 48º 31’ 26,1” W). In these studies we obtained three specimens from each species. From each specimen we collected the most developed branches of the treetops. From the collected branches, samples were taken and its basal portion polished for the qualitative macroscopic analysis and also for the qualitative and quantitative microscopic analysis of the secondary xylem characteristics. From these analyses, we verified the presence of perforated ray cells (PRC) in seven species and also we decided to collect roots to verify the presence of PRC’s in the secondary xylem of these species. The roots were collected to a depth of 30 cm, and on the samples qualitative and quantitative analyses were performed on the PRC. On the secondary xylem of branches we characterized the growth ring markers and described the structure of the growth layer. The following patterns were observed: growth rings well defined (61%), poorly defined (33%), absent (6%); diffuse-porous (94%) and semi-ring-porous (6%); without vessel arrangement (84%), in radial pattern (10%) and in tangential bands (6%); solitary and multiple vessels (94%) and exclusively solitary (6%); simple perforation plate (90%) ...(Complete abstract click electronic access below)
Descrição
Palavras-chave
Cerrados, São Paulo (Estado), Madeira - Anatomia, Anatomia vegetal, Cerrado species, Growth ring, Wood anatomy
Como citar
OLIVEIRA, Julia Sonsin. Variações estruturais do lenho de espécies de cerrado do estado de São Paulo. 2007. 129 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Biociências de Botucatu, 2007.