35 research outputs found

    Diferenças anatômicas e nos anéis de crescimento em árvores de duas procedências de Cordia trichotoma (Vell.) Arráb. ex Steud. (Boraginaceae)

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    The parental effect on wood anatomy and growth rings of Cordia trichotoma trees was studied. Tree seeds of two provenances (Cerrado and Atlantic Forest biomes) were collected in 1986. Seedlings were planted, and after 25 years, twelve wood disks were collected from six trees from each provenance. Anatomical features and growth rings were analyzed according to standard techniques. Qualitative anatomy of wood indicated similarities between the two provenances, except for the presence of geniculate vessels found in woods from the Cerrado. However, the greatest differences in wood anatomy were quantitative. Provenances from Cerrado had wood with shorter vessel and fibers elements, less fiber lumen, less parenchyma per mm2, and more vessels per group than did provenances from the Atlantic Forest. Cross dating among the radial growth ring series was performed through visual and statistical procedures. The relationships between tree rings and meteorological records were performed through Pearson's correlation, and through dendro-climatic analysis that identified the end summer precipitation as the major factor affecting tree growth at inter annual timescale. The standard chronologies of tree-ring width series showed similarity between Cerrado and Atlantic Forest provenances, but with small differences in the juvenile period of live of trees. The rains that decreased between April and June associated with the gradual decrease in temperature may have reduced the cambial activity and caused the formation of tree rings with small differences between the two provenances. The results of this study are relevant for climate adaptive forestry: they emphasize the importance of heritability in the plasticity of certain features of wood anatomy related to the environmental conditions in which they grow, while the growth rate and its year-by-year variability show small differences.O efeito parental na anatomia da madeira e nos anéis de crescimento de árvores de Cordia trichotoma foi estudado. Sementes de árvores de duas procedências (biomas Cerrado e Mata Atlântica) foram coletadas em 1986. Mudas foram plantadas e após 25 anos foram cortados doze discos de madeira de seis árvores de cada procedência. Características anatômicas e dos anéis de crescimento foram analisados de acordo com técnicas padrão. A anatomia qualitativa da madeira indicou semelhanças entre as duas procedências, exceto pela presença de vasos geniculados encontrados em madeiras do Cerrado. No entanto, as maiores diferenças na anatomia da madeira foram quantitativas. As procedentes do Cerrado apresentaram madeira com elementos de vasos e fibras mais curtos, fibras com menor lume, menor porcentagem de parênquima por mm2 e mais vasos por grupo do que as procedentes da Mata Atlântica. A datação cruzada entre as séries de anéis de crescimento radial foi realizada por meio de procedimentos visuais e estatísticos. As relações entre os anéis das árvores e os registros meteorológicos foram realizadas por meio da correlação de Pearson, e por análise dendroclimática foi identificada a precipitação do final do verão como o principal fator que afeta o crescimento das árvores na escala de tempo interanual. As cronologias padrão das séries de larguras de anéis das árvores mostraram similaridade entre as procedências do Cerrado e da Mata Atlântica, mas com pequenas diferenças no período juvenil de vida das árvores. As chuvas que diminuíram entre abril e junho associadas à diminuição gradativa da temperatura podem ter reduzido a atividade cambial e ocasionado a formação de anéis das árvores com pequenas diferenças entre as duas procedências. Os resultados deste estudo são relevantes para a silvicultura adaptativa ao clima, e enfatizam a importância da herdabilidade na plasticidade de certas características da anatomia da madeira relacionadas às condições ambientais em que crescem, e a taxa de crescimento e sua variabilidade ano a ano também mostram pequenas diferenças.Fil: Longui, Eduardo Luiz. Instituto de Pesquisas Ambientais; BrasilFil: Caum, Caroline. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Tomazello Filho, Mario. Universidade do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; BrasilFil: Lisi, Claudio Sergio. Universidade Federal de Sergipe; BrasilFil: Roig Junent, Fidel Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina. Universidad Mayor; ChileFil: Marcati, Carmen Regina. Universidade Estadual Paulista Julio de Mesquita Filho; Brasi

    A contribution to the identification of charcoal origin in Brazil II : macroscopic characterization of cerrado species

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    O cerrado brasileiro é a savana mais rica do mundo. Também é um dos biomas mais ameaçados do país e um hotspot de prioridade de conservação. As principais causas do desmatamento no cerrado são as práticas agrícolas, pecuária e produção de carvão vegetal. Apesar da produção de carvão possuir menor impacto, seu consumo representa o desmatamento de 16.000 Km² do cerrado. Para a conservação do bioma é essencial aprimorar a fiscalização florestal. Assim sendo, neste trabalho apresentamos a caracterização macroscópica de carvão vegetal de 25 espécies do cerrado. Simulamos as condições reais de profissionais que realizam a fiscalização, usando ampliações de 10x, 25x e 65x. Igualmente, as micrografias dos carvões são todas das seções transversais devido à maior quantidade de informações anatômicas. Analisamos também a textura, o brilho, a vitrificação, rupturas e alguns caracteres especiais. As espécies apresentam várias diferenças em sua estrutura anatômica. Embora algumas sejam muito características, este trabalho não tem intenção de identificar carvões apenas por análises de macroscopia. Mas pode fornecer orientações para futura identificação de gêneros ou espécies. Também fornece conhecimento para os agentes governamentais poderem verificar os documentos de origem florestal por análise rápida de amostra do próprio carvão.The Brazilian Cerrado is the richest savanna in the world. It is also one of the biomes more threatened in the country and a hotspot for conservation priorities. The main causes of deforestation in Cerrado are agricultural practices, livestock and charcoal production. Although charcoal has a minor impact, its consumption represents the deforestation of 16.000 Km² of the Cerrado. To contribute for the biomes's conservation it is very important to improve forestry supervision. Thus, in this work we present the macroscopic characterization of charcoal from 25 Cerrado's species. We simulate the real conditions of forest controllers by using the magnifications of 10x, 25x and 65x. Likewise, the charcoals micrographs are all of transverse sections due to the larger amount of anatomical information. We also analyzed texture, brightness, vitrification, ruptures and some special features. The species present several differences in their anatomical structure. Although some of them are very unique, this work does not intent to identify charcoals only by macroscopic analyses. But it might give directions to future identification of genera or species. It also provides knowledge for government agents to verify the documents of forestry origin by fast analyzing a sample of charcoal itself

    The role of organ and leaf habit on the secondary xylem anatomy variation across 15 species from Brazilian Cerrado

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    Xylem is a complex tissue connecting the organs of plants and it performs multiple functions, including water transport, mechanical support, and storage. Because of the interaction between structure and function, xylem anatomy can provide useful information about its role in plant strategies. However, knowledge of how xylem anatomical traits change across organs and species functional groups is still limited. Here, we tested the role of different plant organs (stem and roots) and leaf habits (deciduous, semi-deciduous, and evergreen) on xylem anatomy variation across 15 woody species from the Brazilian Cerrado. Vessels, fibers, and parenchyma traits were measured on 45 individuals sampled in 2014 in Botucatu, São Paulo, Brazil. Our results revealed a higher parenchyma fraction and less fiber fraction in roots than in stems across species. Differences in wood anatomical traits between organs were mainly species-specific in parenchyma traits rather than vessel and fiber traits. Across leaf habits, only the root ray fraction was higher in evergreen species compared to deciduous species. These findings highlight a potential role of organs and leaf habits in xylem storage across Cerrado woody species

    Seasonal presence of acicular calcium oxalate crystals in the cambial zone of Citharexylum myrianthum (Verbenaceae)

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    This study focuses on the seasonal presence of acicular crystals in the cambial zone of Citharexylum myrianthum Chain. (Verbenaceae). Specimens collected in different months from 1996 to 2000 were examined for the abundance of acicular crystals in the cambium. This information was correlated with the phenology of the species and the climate of the region. Acicular calcium oxalate crystals were found in cambial fusiform and ray cell initials, as well as in their daughter cells. An abundance of crystals was observed during periods of water deficit and leaf fall (July). Fewer crystals were found in the beginning of the wet season and bud swelling (September). When trees were flowering and the soil was wet (November and December), acicular crystals were rarely observed. During this period, acicular crystals were found in differentiating phloem and xylem parenchyma cells, in fully differentiated phloem cells, but not in fully differentiated xylem cells

    Anatomia comparada do lenho em raiz e caule de Lippia salviifolia Cham. (Verbenaceae)

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    O presente trabalho vem contribuir com informações sobre a anatomia estrutural da madeira de raiz e caule de L. salviifolia Cham. (Verbenaceae). O estudo foi conduzido em área de cerrado, no Município de Pratânia, Estado de São Paulo (23º02'55,5 S e 48º31'26,1 W). Três espécimes de Lippia salviifolia foram coletados. Amostras do caule foram coletadas à altura do peito (AP), isto é, a 1,30 m do solo e as amostras de raiz foram coletadas de 30 a 40 cm da base do tronco. Houve variação qualitativa e quantitativa entre o lenho de raiz e de caule. As características quantitativas mais relevantes que diferenciam o lenho da raiz do de caule em L. salviifolia foram comprimento e freqüência de vasos, comprimento, diâmetro e espessura da parede das fibras e largura e altura de raios. Camadas de crescimento bem definidas foram observadas no lenho de caule e raiz. Placas de perfuração simples e múltiplas foram observadas nos elementos de vaso tanto no lenho de caule quanto no de raiz, entretanto placas radiadas foram encontradas apenas no lenho de raiz. Foram observadas fibras septadas e raios mais largos no lenho de raiz.Wood from stem and root of L. salviifolia Cham. (Verbenaceae) was studied. Three plants were sampled in a cerrado area in Pratânia municipality, São Paulo state (23º02'55,5 S e 48º31'26,1 W). Stem samples were collected at breast height (1.30 m from soil), and root samples were collected 30 to 40 cm from the stem base. There were qualitative and quantitative variations between root and stem wood. The most relevant quantitative characteristics diferentiating root wood from stem wood were: vessel elements length and frequency; fibre length, diameter and wall thickness; and ray width and height. Well defined growth increments were observed in root and stem wood. Simple and multiple perforation plates were observed in vessel elements in root and stem wood, however radiate plates were observed only in root wood. Septate fibres and wider rays were observed in root wood.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Anatomia e uso da madeira de duas variedades de Sclerolobium paniculatum Vog. do sul do Maranh\ue3o, Brasil

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    O presente estudo traz informações sobre a utilização da madeira de duas variedades de Sclerolobium paniculatum (var. subvelutinum e rubiginosum) em propriedades rurais do sul do Maranhão, a análise anatômica do lenho e a correlação destas características com o uso da madeira. Foram realizadas entrevistas com 17 agricultores residentes na zona rural dessa região, com a finalidade de se conhecer a utilização destas variedades nas propriedades rurais. As variedades subvelutinum Benth. e rubiginosum (Mart. ex Tul. ) Benth. são conhecidas na região como cachamorra-preta e cachamorra-branca, respectivamente, sendo a primeira mais utilizada na confecção de cercados. Para o estudo anatômico do lenho, foram coletados discos à altura do peito de três indivíduos de cada variedade e, destes, obtidas amostras do cerne, na região de transição com o alburno. As amostras foram processadas de acordo com a metodologia usual para anatomia de madeira. Houve diferença estatística significativa (p<0,05) para seis parâmetros anatômicos entre as duas variedades. A utilização diferencial das variedades pode ser decorrente, principalmente, das características das fibras e dos elementos de vasos. Sugere-se que sejam realizados estudos que abordem variações climáticas e características do solo para melhor entendimento das diferenças anatômicas quantitativas encontradas no lenho das variedades

    Stem anatomy and development of successive cambia in Hebanthe eriantha (Poir.) Pedersen: A neotropical climbing species of the Amaranthaceae

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    Hebanthe eriantha (Poir.) Pedersen, a climbing species of the Amaranthaceae increases in stem thickness by forming successive cambia. The family is dominated by herbaceous species and is constantly under discussion due to its disputed nature of the meristem. In the young stem small alternate segments of vascular cambium cease to divide and new arc of cambium initiates outside to it. The newly formed arcs connect with pre-existing alternate segments of cambium to complete the ring. On the contrary, in thick stems, instead of small segments, complete ring of cambium is replaced by new one. These new alternate segments/cambia originate from the parenchyma cells located outside to the phloem produced by previous cambium. Cambium is storied and exclusively composed of fusiform initials while ray cells remain absent at least in the early part of the secondary growth. However, large heterocellular rays are observed in 15-mm diameter stems but their frequency is much lower. In some of the rays, ray cells become meristematic and differentiate into radially arranged xylem and phloem elements. In fully grown plants, stems are composed of several successive rings of secondary xylem alternating with secondary phloem. Secondary xylem is diffuse-porous and composed of vessels, fibres, axial parenchyma while exceptionally large rays are observed only in the outermost regions of thick stems. Vessel diameter increases progressively from the centre towards the periphery of stems. Although the origin of successive cambia and composition of secondary xylem of H. eriantha remains similar to other herbaceous members of Amaranthaceae, the occurrence of relatively wider and thick-walled vessels and large rays in fully grown plants is characteristic to climbing habit. © 2013 Springer-Verlag Wien

    Anatomia comparada do lenho de Copaifera langsdorffii Desf. (Leguminosae-Caesalpinoideae) de floresta e cerradão

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    O presente estudo compara a estrutura do lenho de uma espécie arbórea (Copaifera langsdorffii Desf.) que ocorre em floresta mesófila semidecídua e em cerradão. Objetivou-se verificar diferenças estruturais qualitativas e quantitativas nos espécimes em relação aos dois ecossistemas. A análise estatística revelou um maior diâmetro tangencial dos vasos nos espécimes do cerradão e um maior diâmetro tangencial das pontoações intervasculares nos espécimes da floresta, ambos ao nível de 0,05. Fibras gelatinosas foram encontradas em maior quantidade nos espécimes do cerradão quando comparadas com os espécimes da floresta. A presença de um parênquima marginal que se subdivide e algumas faixas parenquimáticas que não apresentam canais axiais são pela primeira vez mencionadas em Copaifera langsdorfii.The present study compares qualitative and quantitative characters of the wood of a tree species (Copaifera langsdorffii Desf.-Leguminosae-Caesalpinoideae) from semideciduous mesophytic forest and cerradão. Analysis revealed vessels with significantly larger diameter in trees from cerradão and intervascular pits being significantly larger in trees from forest. In contrast to the trees from the forest, gelatinous fibers, which have a special layer innermost of the wall, were found in great quantity in trees from cerradão. Furthermore, the presence of subdivided marginal parenchyma and the absence of axial canals in some of the parenchyma bands are for the first time mentioned for this species.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Seasonal variation in wood formation of Cedrela fissilis (Meliaceae)

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    Cambial activity and periodicity of secondary xylem formation in Cedrela fissilis, a semi-ring-porous species, were studied. Wood samples were collected periodically from 1996 to 2000. The phenology was related to climate data of the region. The cambium has one active and one dormant period per year. The active period coincides with the wet season when trees leaf-out. The dormant period coincides with the dry season when trees lose their leaves. Growth rings are marked by parenchyma bands that begin to be formed, together with the small latewood vessels, just before the cambium becomes dormant at the beginning of the dry season. These bands are added to when the cambium reactivates in the wet season. At this time, the large earlywood vessels of the growth rings are also formed. As these bands consist of both terminal and initial parenchyma, we suggest the general term marginal bands be used to describe them. The growth layers vary in width among and within the trees

    STEM ANATOMY and DEVELOPMENT of SUCCESSIVE CAMBIA IN THE NEOTROPICAL LIANA SECURIDACA RIVINIFOLIA (POLYGALACEAE)

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    The pattern of secondary growth and structure of secondary xylem was studied in the stem of the Neotropical liana Securidaca rivinifolia A. St.-Hil. (Polygalaceae). Increase in thickness of the stem was achieved by formation of successive cambia, from which initially two or three successive rings formed complete oval to circular cambia. Thereafter, the successive cambia were always crescent-shaped and never formed a complete cylinder, resulting in dumbbell-shaped cross-sectional outlines of the stems. The first successive cambium originated in the pericyclic parenchyma located outside the crushed protophloem. Prior to the development of cambium, pericyclic parenchyma formed a meristematic band of radially arranged cells. From this band, cells located in the middle of the band became the new ring of cambium. Cells on the inner face of the xylem produced by newly formed cambium differentiated into conjunctive tissue. The first elements to be differentiated from the newly developed cambium were always xylem fibres but differentiation of vessels was also observed occasionally. The xylem was diffuse porous with relatively distinct growth rings and composed of mostly solitary vessels with simple perforation plates, fibres with bordered pits, paratracheal axial parenchyma, and exclusively uniseriate rays.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
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