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1.
Sci Rep ; 10(1): 3424, 2020 02 25.
Artículo en Inglés | MEDLINE | ID: mdl-32099071

RESUMEN

Climatic factors can influence the establishment and growth of wood species, but little is known about the effect of these factors on monodominant communities in wetlands. Therefore, we asked how climatic factors, such as ENSO (El Niño-Southern Oscillation), precipitation and flooding, influence growth and establishment of the dominant species Erythrina fusca in the Pantanal. We determined the age of sampled individuals, the age of the population and evaluated the effects of climate on tree growth. We obtained samples for dendrochronological analyses using destructive (seven individuals) and non-destructive methods. We cross-dated and built a chronology, correlating results with climatic factors. We sampled 0.6 ha of the population and separated individuals into diameter classes to determine age based on diameter/age ratio obtained through dendrochronological analyses. We obtained a chronology with individuals up to 34 years old, while in the population sample, the oldest individual was 54 years old. The factors that influenced growth during the study period were precipitation (positive correlation) and El Niño (negative correlation). E. fusca individuals seem to grow more during the period of highest precipitation, and El Niño events reduce precipitation in the Pantanal, resulting in a decrease in the growth of E. fusca individuals. We detected a decrease of young individuals in the last nine years, which seems to be related to the decrease in minimum flood levels. This indicates a future decline in the number of individuals. These results allow us to propose measures to protect these monodominant formations, which mainly involve avoiding further anthropic activities, that could reduce flooding levels.

2.
An Acad Bras Cienc ; 87(2): 787-96, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25910176

RESUMEN

Large elongated glands occur on Cercideae leaf surfaces. Leaves of Bauhinia (55 taxa, 53 species), Cercis (1 species), Phanera (1 species), Piliostigma (2 species), Schnella (19 species) and Tylosema (1 species) were observed to determine location and relative number of glands. They were only observed on the abaxial leaf surface of 42 Bauhinia taxa. The glands were analyzed by light stereomicroscope and scanning electron microscopy. They are large (up to 270 µm long and 115 µm wide) and multicellular, containing lipophilic substances, probably volatile oils. Presence or absence and density of the glands in species of Bauhinia may be useful to determine species delimitation or distinction among infraspecific taxa. Higher density of glands is more common in species from "cerrado" (a savanna ecosystem) and "caatinga" (a semiarid ecosystem from northeast Brazil) areas. Bauhinia species devoid of foliar glands are frequently from humid forests.


Asunto(s)
Bauhinia/ultraestructura , Hojas de la Planta/ultraestructura , Bauhinia/clasificación , Bauhinia/citología , Microscopía Electrónica de Rastreo , Hojas de la Planta/citología , Especificidad de la Especie
3.
Rev. bras. farmacogn ; 21(3): 373-381, maio-jun. 2011. ilus, tab
Artículo en Inglés | LILACS | ID: lil-593281

RESUMEN

Eugenia rotundifolia Casar., Myrtaceae, occurs in the sandy coastal environments of Rio de Janeiro and Espírito Santo States. To the best of our knowledge, E. rotundifolia was not included in ethnobotanical and nor in pharmacological research, but its leaves are sold in a public market of Rio de Janeiro City as "abajurú", the common name for Chrysobalanus icaco L., Chrysobalanaceae. C. icaco, in contrast, has been studied and its medicinal effects reported. Since E. rotundifolia is often sold in the public market as "abajurú," this paper describes and compares the leaf anatomy and morphology of E. rotundifolia with C. icaco, previously described in the literature, in order to provide tools for the authentication of commercialized "abajurú." Phyllotaxy; texture; color; margin; midrib prominence; stomata type; type and shape of midrib and petiole vascular bundle; the presence of marginal vein, secretory cavities, which are seen as translucent dots, and overlying cells only in E. rotundifolia; and the presence of trichomes, periclinal divisions in adaxial face epidermis, hypodermis and vascular bundle extensions only in C. icaco were found to be the most distinguishable diagnostic characters.

4.
An. acad. bras. ciênc ; 77(2): 259-274, June 2005. ilus
Artículo en Inglés | LILACS | ID: lil-399100

RESUMEN

A proposta deste trabalho é mostrar uma nova interpretação do meristema de espessamento primário em monocotiledôneas. Anatomia dos órgãos vegetativos das seguintes espécies foi examinada: Cephalostemon riedelianus (Rapataceae), Cyperus papyrus (Cyperaceae), Lagenocarpus rigidus, L. Junciformis (Cyperaceae), Echinodorus paniculatus (Alismataceae) and Zingiberofficinale (Zingiberaceae). A atividade meristemática da endoderme foi observada nas raizes de todas as espécies, no caule de Cyperus, Cephalostemum e Lagenocarpus rigidus, e no traço foliar de Cyperus e folha de Echinodorus. Considerando a continuidade dos tecidos através da raiz, caule e folha, as autoras concluem que no caule o periciclo permanece ativo durante a vida da planta, como um gerador de tecidos vasculares. O "Meristema de Espessamento Primário" é o periciclo em fase meristemática, juntamente com a endoderme e suas derivadas (ou apenas o periciclo). Próximo ao ápice caulinar, esses tecidos se assemelham a um único meristema, dando origem ao córtex interno e aos tecidos vasculares.


Asunto(s)
Magnoliopsida/citología , Endodermo/fisiología , Meristema/fisiología , Magnoliopsida/fisiología , Meristema/citología
5.
An Acad Bras Cienc ; 77(2): 259-74, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15895162

RESUMEN

This paper proposes a new interpretation for primary thickening in monocotyledons. The anatomy of the vegetative organs of the following species was examined: Cephalostemon riedelianus (Rapataceae), Cyperus papyrus (Cyperaceae), Lagenocarpus rigidus, L. junciformis (Cyperaceae), Echinodorus paniculatus (Alismataceae) and Zingiber officinale (Zingiberaceae). The endodermis with meristematic activity was observed in the root of all the species, in the stem of Cyperus, Cephalostemum and Lagenocarpus rigidus, and in the leaf trace of Cyperus and leaf of Echinodorus. Considering the continuity of tissues through the root, stem and leaf, the authors conclude that in the stem the pericycle remains active throughout the life of the plant as the generator of the vascular tissue. The "Primary Thickening Meristem" is in fact the pericycle plus the endodermis and its derivatives (or only the pericycle). Close to the stem apex, the assemblage of seems to be a unique meristem, giving rise to the inner cortex and vascular tissues.


Asunto(s)
Endodermo/fisiología , Magnoliopsida/citología , Meristema/fisiología , Magnoliopsida/fisiología , Meristema/citología
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