ECOLOGICAL WOOD ANATOMY OF Blepharocalyx salicifolius (H. B. K.) Berg

O presente trabalho visa \ue0 compara\ue7\ue3o anat\uf4mica da madeira da murta Blepharocalyx salicifolius (H. B. K.) Berg (Myrtaceae), em duas regi\uf5es do Rio Grande do Sul. Foram coletados seis exemplares da esp\ue9cie; tr\ueas na regi\ue3o da Serra do Sudeste e os demais nos Campos de Cima da Serra. Qualitativamente, a madeira n\ue3o revelou diferen\ue7as expressivas entre as proced\ueancias, exceto pela presen\ue7a de m\ue1culas medulares. Sob o ponto de vista de suas caracter\uedsticas quantitativas, foram encontradas diferen\ue7as importantes na estrutura de vasos, par\ueanquima axial, raios e fibras. As amostras da "Serra do Sudeste" mostraram caracter\uedsticas x\ue9ricas no lenho: poros numerosos e pequenos, al\ue9m de elementos vasculares e fibras de comprimento menor, diferentemente das amostras dos "Campos de Cima da Serra". Quanto ao \uedndice de vulnerabilidade, n\ue3o foi encontrada diferen\ue7a significativa entre as proced\ueancias. As altera\ue7\uf5es verificadas no lenho podem ser interpretadas como resposta adaptativa da esp\ue9cie aos respectivos ambientes.The purpose of this work is the comparison of the wood anatomy of Blepharocalyx salicifolius (H. B. K.) Berg (Myrtaceae) from two provenances in the State of Rio Grande do Sul. There were collected 6 samples of wood; three from "Serra do Sudeste" and the others from "Campos de Cima da Serra". The wood anatomical features did not express relevant differences between provenances, with the exception of pith flecks. With respect to the quantitative features, on the other hand, there were found important differences in the structure of vessels, axial parenchyma, rays and fibres. For the "Serra do Sudeste" samples, there were found xeric evidences in the wood: a larger number of small vessels, besides shorter vessel members and fibres, in comparison with those from the "Campos de Cima da Serra" region. The differences in the wood anatomy may be interpreted as adaptative responses to environmental conditions

STRUCTURAL DIVERSITY IN Eugenia L. (Myrtaceae)

No presente estudo \ue9 investigada a anatomia da madeira de 9 esp\ue9cies sul-rio-grandenses de Eugenia (Myrtaceae), com vistas ao reconhecimento de caracteres \ufateis \ue0 identifica\ue7\ue3o do g\ueanero e esp\ue9cies. Os resultados demonstram uma grande homogeneidade estrutural, fruto do elevado n\ufamero de caracteres anat\uf4micos compartilhados. Nenhuma caracter\uedstica ocorre exclusivamente no grupo taxon\uf4mico em quest\ue3o. \uc9 confirmado o valor do arranjo do par\ueanquima axial para a separa\ue7\ue3o de esp\ue9cies, bem como da frequ\ueancia de poros e caracter\uedsticas de raios. N\ue3o \ue9 poss\uedvel contestar, com base na anatomia da madeira, a inclus\ue3o de Hexachlamys em Eugenia, como sugerido por Landrum e Kawasaki (1997).The wood anatomy of nine species of Eugenia (Myrtaceae) native in Rio Grande do Sul State (Brazil) is presently studied in order to identify diagnostic characters useful to identify genus and species. A great structural homogeneity was observed, reflecting the high number of shared anatomical features. None characteristic is exclusive to this taxonomic group. The value of axial parenchyma arrangement to species segregation is confirmed, as well as the frequency of pores and characteristics of rays. It is not possible to disprove, based on wood anatomy, the inclusion of Hexachlamys in Eugenia, as suggested by Landrum and Kawasaki (1997)

UNDERSTOREY OF PINE-PLANTATIONS ON DEGRADED SITES IN THE REGION OF DECIDUOUS FORESTS OF RIO GRANDE DO SUL

Analisou-se o sub-bosque de 12 povoamentos de Pinus sp. e um de Araucaria angustifolia O.Ktze., crescendo em solos degradados pelo uso agr\uedcola na chamada 4a Col\uf4nia do Rio Grande do Sul. A Araucaria foi semeada diretamente, um dos povoamentos de Pinus, de 10 anos, resultou de uma renova\ue7\ue3o natural, os demais prov\ueam de plantios de 25 a 30 anos atr\ue1s. Em 575 parcelas de 25 m2 cada, distribu\ueddas sistematicamente nos povoamentos, foram levantados o estrato arb\uf3reo e a vegeta\ue7\ue3o inferior, classificada em estratos de 0,3 a 1,3 m e maior que 1,3 m; no estrato inferior a 0,3 m somente a renova\ue7\ue3o natural de Pinus foi contada. A vegeta\ue7\ue3o interna dos povoamentos se comp\uf4s de 121 esp\ue9cies lenhosas, incluindo esp\ue9cies desde comuns at\ue9 nobres, mas tamb\ue9m ornamentais ou frut\uedferas nativas e ex\uf3ticas. Um bom n\ufamero de esp\ue9cies, por\ue9m, ocorreu com poucos representantes. Al\ue9m disso registrou-se a presen\ue7a freq\ufcente de esp\ue9cies n\ue3o-arb\uf3reas como ervas, gramas, samambaias e cip\uf3s. O n\ufamero de esp\ue9cies e o grau de cobertura do sub-bosque n\ue3o dependiam da densidade do estrato superior de pinheiros. A abund\ue2ncia e a freq\ufc\ueancia das esp\ue9cies n\ue3o variavam significativamente entre parcelas do centro dos povoamentos e da faixa perif\ue9rica. O padr\ue3o de distribui\ue7\ue3o espacial das plantas dentro dos povoamentos foi quantificado pelo \ucdndice de Cox. O \ucdndice de Shannon foi usado como medida da diversidade em esp\ue9cies; pelo \ucdndice de S\uf6rensen foi estudada a semelhan\ue7a dos povoamentos. Conclui-se que plantios de ex\uf3ticas nessa regi\ue3o n\ue3o somente podem ser de interesse para os agricultores pelo elevado potencial produtivo em madeira, como tamb\ue9m significam manchas de inesperada biodiversidade numa paisagem degradada. A riqueza do sub-bosque possivelmente se deve \ue1 extens\ue3o reduzida desses povoamentos.In the central part of Rio Grande do Sul State understoreys of 12 stands of Pinus sp. and one of Araucaria angustifolia O.Ktze were studied, all growing on soils, degraded by agriculture. One pine stand, 10 years old, originated from a natural renovation, the others had been planted 25 to 30 years ago, Araucaria was seeded directly. A total of 575 plots were sampled, 25 m2 each, distributed systematically within the stands. Measurements included pines overstorey, and all understorey woody species, separeted into layers of more than 1,3 m high and 1,3 to 0,3 m; the layer lower than 0,3 m included only natural renovation of pines. Understoreys were composed by 121 species, ocurring common and high value timber species, ornamental trees, native and exotic fruit tree species. A higher number of species was present with a very few individuals only. The presence of non woody species like grasses, herbs, ferns and lians also was quantified. The number of tree species and the presence of non woody species did not correlat with density of overstorey pines. Abundance and frequency of species showed no significant diferences, when samples were grouped according to their location in the center or close to stands edge. Distribution pattern of understorey trees within stands was quantified, using Cox\u2019 index, species diversity was compared by means of Shannon-index. Similarity of stands was compared by S\uf6rensen-Index. It was concluded, that exotic species planted on poor agricultural soil may not only be of farmers interest because of their high potential for wood production. These plantations also may be considered from conservationist point of view, since they show an unexpected high diversity, so contributing in a longer run to landscape improvement, possibly due to the small extension of stands

WOOD ANATOMY OF TWO SPECIES OF THE GENUS Heterothalamus Lessing (ASTERACEAE) FROM RIO GRANDE DO SUL (BRAZIL)

O presente trabalho descreve a anatomia da madeira de Heterothalamus alienus e Heterothalamus rupestris (Astereae \u2013 Asteraceae), como parte do estudo do xilema secund\ue1rio do referido g\ueanero. Para ambas as esp\ue9cies, foram confirmados detalhes anat\uf4micos mencionados na literatura para a fam\uedlia Asteraceae, como vasos tipicamente pequenos e agrupados em padr\ue3o dendr\uedtico, placas de perfura\ue7\ue3o invariavelmente simples e par\ueanquima paratraqueal. Heterothalamus alienus possui espessamentos espiralados nos vasos lenhosos e par\ueanquima axial vasic\ueantrico estratificado. Heterothalamus rupestris distingue-se pela aus\ueancia de espessamentos espiralados nos vasos e pelo par\ueanquima paratraqueal vasic\ueantrico a unilateral. S\ue3o fornecidas fotomicrografias, dados quantitativos de caracter\uedsticas anat\uf4micas e uma compara\ue7\ue3o entre a madeira das duas esp\ue9cies.The present work describes the wood anatomy of Heterothalamus alienus and Heterothalamus rupestris (Astereae - Asteraceae), as part of the secondary xylem study in the named genus. For the two species it was recorded some features usually mentioned in the literature for the Asteraceae, as typically small vessels, grouped in a dendritic pattern, the presence of only simple perforation plates and of paratracheal parenchyma. Heterothalamus alienus shows spiral thickenings in the wood vessels and storied vasicentric axial parenchyma. Heterothalamus rupestris differs itself by the absence of spiral thickenings in wood vessels and by no storied axial parenchyma, in paratracheal vasicentric to unilateral patterns. Photomicrographs, quantitative data of anatomical features and a comparison between the two species of wood are also provided

ANATOMIA DA MADEIRA DE PHYLLANTHUS SELLOWIANUS M\ufcll. ARG. (PHYLLANTHACEAE)

The present study aimed to describe the wood anatomy of Phyllanthus sellowianus M\ufcll. Arg.(Phyllanthaceae), as well as the research of anatomical characters associated with the flexibility of their stems, desirable characteristic for bioengineering works. Belonging to the group of reophyllous and with up to three meters in height, the species occurs naturally in the south of Brazil, Uruguay and Argentina. The exsicat and wood sample from a P. sellowianus, located in the municipality of Santa Maria, Rio Grande do Sul state, Brazi, were deposited in the University Federal de Santa Maria under the numbers HDCF 5587 e 5588. Standard technique was used to set the histological lamina of wood. For macerations used the method of Jeffrey. The Wood anatomy description followed the IAWA Committee (1989). The microscopic analysis revealed the presence vassels of small diameter (< 60\u3bcm), radial multiples of 2 to 4 units, and simple perforation plates, obliquely, axial parenchyma absent, heterogeneous rays, with 1-3 cells large, and gelatinous fibers. The absence of axial parenchyma and laticifer tubes is compatible to the Phyllanthaceae group. The presence of perforated ray cells is, probably, the main anatomic component for differentiation of P. sellowianus from the other species of the genera. The abundant presence of gelatinous fibers certainly is one of the main anatomical characteristics related to the high flexibility of its stem.O presente estudo teve por objetivos descrever anatomicamente o lenho de Phyllanthus sellowianus M\ufcll. Arg. (Phyllanthaceae), bem como investigar caracteres anat\uf4micos associados \ue0 flexibilidade de seus caules, caracter\uedstica desej\ue1vel para obras de bioengenharia em taludes fluviais. Pertencente ao grupo das re\uf3filas, e com at\ue9 3 metros de altura, a esp\ue9cie ocorre naturalmente no sul do Brasil, Uruguai e Argentina. As exsicatas e as amostras de madeira, provenientes de um exemplar localizado no munic\uedpio de Santa Maria-RS (Brasil), foram acondicionadas no Herb\ue1rio e Xiloteca da Universidade Federal de Santa Maria, sob os n\ufameros HDCF 5587 e 5588. Para a confec\ue7\ue3o das l\ue2minas histol\uf3gicas de madeira, seguiu-se a t\ue9cnica padr\ue3o. Para a macera\ue7\ue3o, utilizou-se o m\ue9todo de Jeffrey. A descri\ue7\ue3o anat\uf4mica da madeira seguiu as recomenda\ue7\uf5es do IAWA Committee (1989). A an\ue1lise microsc\uf3pica do lenho revelou a presen\ue7a de poros com pequeno di\ue2metro (< 60 \u3bcm), dispostos em m\ufaltiplos radiais de 2 \u2013 4 unidades, e de placas de perfura\ue7\ue3o simples, obl\uedquas; par\ueanquima axial ausente, raios heterog\ueaneos, com 1 \u2013 3 c\ue9lulas de largura, e fibras gelatinosas. A aus\ueancia de par\ueanquima axial e de tubos latic\uedferos \ue9 compat\uedvel com o grupo das Phyllanthaceae. A presen\ue7a de c\ue9lulas perfuradas de raio constitui-se, possivelmente, no principal elemento anat\uf4mico para a diferencia\ue7\ue3o de P. sellowianus em rela\ue7\ue3o \ue0s demais esp\ue9cies do g\ueanero. A presen\ue7a abundante de fibras gelatinosas \ue9 seguramente uma das principais caracter\uedsticas anat\uf4micas relacionadas \ue0 elevada flexibilidade de seu caule